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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance events updates from Ingo Molnar:
"Seqlock optimizations that arose in a perf context and were merged
into the perf tree:
- seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
- mm: Convert mm_lock_seq to a proper seqcount (Suren Baghdasaryan)
- mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren
Baghdasaryan)
- mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)
Core perf enhancements:
- Reduce 'struct page' footprint of perf by mapping pages in advance
(Lorenzo Stoakes)
- Save raw sample data conditionally based on sample type (Yabin Cui)
- Reduce sampling overhead by checking sample_type in
perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin
Cui)
- Export perf_exclude_event() (Namhyung Kim)
Uprobes scalability enhancements: (Andrii Nakryiko)
- Simplify find_active_uprobe_rcu() VMA checks
- Add speculative lockless VMA-to-inode-to-uprobe resolution
- Simplify session consumer tracking
- Decouple return_instance list traversal and freeing
- Ensure return_instance is detached from the list before freeing
- Reuse return_instances between multiple uretprobes within task
- Guard against kmemdup() failing in dup_return_instance()
AMD core PMU driver enhancements:
- Relax privilege filter restriction on AMD IBS (Namhyung Kim)
AMD RAPL energy counters support: (Dhananjay Ugwekar)
- Introduce topology_logical_core_id() (K Prateek Nayak)
- Remove the unused get_rapl_pmu_cpumask() function
- Remove the cpu_to_rapl_pmu() function
- Rename rapl_pmu variables
- Make rapl_model struct global
- Add arguments to the init and cleanup functions
- Modify the generic variable names to *_pkg*
- Remove the global variable rapl_msrs
- Move the cntr_mask to rapl_pmus struct
- Add core energy counter support for AMD CPUs
Intel core PMU driver enhancements:
- Support RDPMC 'metrics clear mode' feature (Kan Liang)
- Clarify adaptive PEBS processing (Kan Liang)
- Factor out functions for PEBS records processing (Kan Liang)
- Simplify the PEBS records processing for adaptive PEBS (Kan Liang)
Intel uncore driver enhancements: (Kan Liang)
- Convert buggy pmu->func_id use to pmu->registered
- Support more units on Granite Rapids"
* tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
perf: map pages in advance
perf/x86/intel/uncore: Support more units on Granite Rapids
perf/x86/intel/uncore: Clean up func_id
perf/x86/intel: Support RDPMC metrics clear mode
uprobes: Guard against kmemdup() failing in dup_return_instance()
perf/x86: Relax privilege filter restriction on AMD IBS
perf/core: Export perf_exclude_event()
uprobes: Reuse return_instances between multiple uretprobes within task
uprobes: Ensure return_instance is detached from the list before freeing
uprobes: Decouple return_instance list traversal and freeing
uprobes: Simplify session consumer tracking
uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
uprobes: simplify find_active_uprobe_rcu() VMA checks
mm: introduce mmap_lock_speculate_{try_begin|retry}
mm: convert mm_lock_seq to a proper seqcount
mm/gup: Use raw_seqcount_try_begin()
seqlock: add raw_seqcount_try_begin
perf/x86/rapl: Add core energy counter support for AMD CPUs
perf/x86/rapl: Move the cntr_mask to rapl_pmus struct
perf/x86/rapl: Remove the global variable rapl_msrs
...
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We are adjusting struct page to make it smaller, removing unneeded fields
which correctly belong to struct folio.
Two of those fields are page->index and page->mapping. Perf is currently
making use of both of these. This is unnecessary. This patch eliminates
this.
Perf establishes its own internally controlled memory-mapped pages using
vm_ops hooks. The first page in the mapping is the read/write user control
page, and the rest of the mapping consists of read-only pages.
The VMA is backed by kernel memory either from the buddy allocator or
vmalloc depending on configuration. It is intended to be mapped read/write,
but because it has a page_mkwrite() hook, vma_wants_writenotify() indicates
that it should be mapped read-only.
When a write fault occurs, the provided page_mkwrite() hook,
perf_mmap_fault() (doing double duty handing faults as well) uses the
vmf->pgoff field to determine if this is the first page, allowing for the
desired read/write first page, read-only rest mapping.
For this to work the implementation has to carefully work around faulting
logic. When a page is write-faulted, the fault() hook is called first, then
its page_mkwrite() hook is called (to allow for dirty tracking in file
systems).
On fault we set the folio's mapping in perf_mmap_fault(), this is because
when do_page_mkwrite() is subsequently invoked, it treats a missing mapping
as an indicator that the fault should be retried.
We also set the folio's index so, given the folio is being treated as faux
user memory, it correctly references its offset within the VMA.
This explains why the mapping and index fields are used - but it's not
necessary.
We preallocate pages when perf_mmap() is called for the first time via
rb_alloc(), and further allocate auxiliary pages via rb_aux_alloc() as
needed if the mapping requires it.
This allocation is done in the f_ops->mmap() hook provided in perf_mmap(),
and so we can instead simply map all the memory right away here - there's
no point in handling (read) page faults when we don't demand page nor need
to be notified about them (perf does not).
This patch therefore changes this logic to map everything when the mmap()
hook is called, establishing a PFN map. It implements vm_ops->pfn_mkwrite()
to provide the required read/write vs. read-only behaviour, which does not
require the previously implemented workarounds.
While it is not ideal to use a VM_PFNMAP here, doing anything else will
result in the page_mkwrite() hook need to be provided, which requires the
same page->mapping hack this patch seeks to undo.
It will also result in the pages being treated as folios and placed on the
rmap, which really does not make sense for these mappings.
Semantically it makes sense to establish this as some kind of special
mapping, as the pages are managed by perf and are not strictly user pages,
but currently the only means by which we can do so functionally while
maintaining the required R/W and R/O behaviour is a PFN map.
There should be no change to actual functionality as a result of this
change.
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250103153151.124163-1-lorenzo.stoakes@oracle.com
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Max Makarov reported kernel panic [1] in perf user callchain code.
The reason for that is the race between uprobe_free_utask and bpf
profiler code doing the perf user stack unwind and is triggered
within uprobe_free_utask function:
- after current->utask is freed and
- before current->utask is set to NULL
general protection fault, probably for non-canonical address 0x9e759c37ee555c76: 0000 [#1] SMP PTI
RIP: 0010:is_uprobe_at_func_entry+0x28/0x80
...
? die_addr+0x36/0x90
? exc_general_protection+0x217/0x420
? asm_exc_general_protection+0x26/0x30
? is_uprobe_at_func_entry+0x28/0x80
perf_callchain_user+0x20a/0x360
get_perf_callchain+0x147/0x1d0
bpf_get_stackid+0x60/0x90
bpf_prog_9aac297fb833e2f5_do_perf_event+0x434/0x53b
? __smp_call_single_queue+0xad/0x120
bpf_overflow_handler+0x75/0x110
...
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__kmem_cache_free+0x1cb/0x350
...
? uprobe_free_utask+0x62/0x80
? acct_collect+0x4c/0x220
uprobe_free_utask+0x62/0x80
mm_release+0x12/0xb0
do_exit+0x26b/0xaa0
__x64_sys_exit+0x1b/0x20
do_syscall_64+0x5a/0x80
It can be easily reproduced by running following commands in
separate terminals:
# while :; do bpftrace -e 'uprobe:/bin/ls:_start { printf("hit\n"); }' -c ls; done
# bpftrace -e 'profile:hz:100000 { @[ustack()] = count(); }'
Fixing this by making sure current->utask pointer is set to NULL
before we start to release the utask object.
[1] https://github.com/grafana/pyroscope/issues/3673
Fixes: cfa7f3d2c526 ("perf,x86: avoid missing caller address in stack traces captured in uprobe")
Reported-by: Max Makarov <maxpain@linux.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250109141440.2692173-1-jolsa@kernel.org
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If kmemdup() failed to alloc memory, don't proceed with extra_consumers
copy.
Fixes: e62f2d492728 ("uprobes: Simplify session consumer tracking")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20241206183436.968068-1-andrii@kernel.org
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While at it, rename the same function in s390 cpum_sf PMU.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Ravi Bangoria <ravi.bangoria@amd.com>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20241203180441.1634709-2-namhyung@kernel.org
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Instead of constantly allocating and freeing very short-lived
struct return_instance, reuse it as much as possible within current
task. For that, store a linked list of reusable return_instances within
current->utask.
The only complication is that ri_timer() might be still processing such
return_instance. And so while the main uretprobe processing logic might
be already done with return_instance and would be OK to immediately
reuse it for the next uretprobe instance, it's not correct to
unconditionally reuse it just like that.
Instead we make sure that ri_timer() can't possibly be processing it by
using seqcount_t, with ri_timer() being "a writer", while
free_ret_instance() being "a reader". If, after we unlink return
instance from utask->return_instances list, we know that ri_timer()
hasn't gotten to processing utask->return_instances yet, then we can be
sure that immediate return_instance reuse is OK, and so we put it
onto utask->ri_pool for future (potentially, almost immediate) reuse.
This change shows improvements both in single CPU performance (by
avoiding relatively expensive kmalloc/free combon) and in terms of
multi-CPU scalability, where you can see that per-CPU throughput doesn't
decline as steeply with increased number of CPUs (which were previously
attributed to kmalloc()/free() through profiling):
BASELINE (latest perf/core)
===========================
uretprobe-nop ( 1 cpus): 1.898 ± 0.002M/s ( 1.898M/s/cpu)
uretprobe-nop ( 2 cpus): 3.574 ± 0.011M/s ( 1.787M/s/cpu)
uretprobe-nop ( 3 cpus): 5.279 ± 0.066M/s ( 1.760M/s/cpu)
uretprobe-nop ( 4 cpus): 6.824 ± 0.047M/s ( 1.706M/s/cpu)
uretprobe-nop ( 5 cpus): 8.339 ± 0.060M/s ( 1.668M/s/cpu)
uretprobe-nop ( 6 cpus): 9.812 ± 0.047M/s ( 1.635M/s/cpu)
uretprobe-nop ( 7 cpus): 11.030 ± 0.048M/s ( 1.576M/s/cpu)
uretprobe-nop ( 8 cpus): 12.453 ± 0.126M/s ( 1.557M/s/cpu)
uretprobe-nop (10 cpus): 14.838 ± 0.044M/s ( 1.484M/s/cpu)
uretprobe-nop (12 cpus): 17.092 ± 0.115M/s ( 1.424M/s/cpu)
uretprobe-nop (14 cpus): 19.576 ± 0.022M/s ( 1.398M/s/cpu)
uretprobe-nop (16 cpus): 22.264 ± 0.015M/s ( 1.391M/s/cpu)
uretprobe-nop (24 cpus): 33.534 ± 0.078M/s ( 1.397M/s/cpu)
uretprobe-nop (32 cpus): 43.262 ± 0.127M/s ( 1.352M/s/cpu)
uretprobe-nop (40 cpus): 53.252 ± 0.080M/s ( 1.331M/s/cpu)
uretprobe-nop (48 cpus): 55.778 ± 0.045M/s ( 1.162M/s/cpu)
uretprobe-nop (56 cpus): 56.850 ± 0.227M/s ( 1.015M/s/cpu)
uretprobe-nop (64 cpus): 62.005 ± 0.077M/s ( 0.969M/s/cpu)
uretprobe-nop (72 cpus): 66.445 ± 0.236M/s ( 0.923M/s/cpu)
uretprobe-nop (80 cpus): 68.353 ± 0.180M/s ( 0.854M/s/cpu)
THIS PATCHSET (on top of latest perf/core)
==========================================
uretprobe-nop ( 1 cpus): 2.253 ± 0.004M/s ( 2.253M/s/cpu)
uretprobe-nop ( 2 cpus): 4.281 ± 0.003M/s ( 2.140M/s/cpu)
uretprobe-nop ( 3 cpus): 6.389 ± 0.027M/s ( 2.130M/s/cpu)
uretprobe-nop ( 4 cpus): 8.328 ± 0.005M/s ( 2.082M/s/cpu)
uretprobe-nop ( 5 cpus): 10.353 ± 0.001M/s ( 2.071M/s/cpu)
uretprobe-nop ( 6 cpus): 12.513 ± 0.010M/s ( 2.086M/s/cpu)
uretprobe-nop ( 7 cpus): 14.525 ± 0.017M/s ( 2.075M/s/cpu)
uretprobe-nop ( 8 cpus): 15.633 ± 0.013M/s ( 1.954M/s/cpu)
uretprobe-nop (10 cpus): 19.532 ± 0.011M/s ( 1.953M/s/cpu)
uretprobe-nop (12 cpus): 21.405 ± 0.009M/s ( 1.784M/s/cpu)
uretprobe-nop (14 cpus): 24.857 ± 0.020M/s ( 1.776M/s/cpu)
uretprobe-nop (16 cpus): 26.466 ± 0.018M/s ( 1.654M/s/cpu)
uretprobe-nop (24 cpus): 40.513 ± 0.222M/s ( 1.688M/s/cpu)
uretprobe-nop (32 cpus): 54.180 ± 0.074M/s ( 1.693M/s/cpu)
uretprobe-nop (40 cpus): 66.100 ± 0.082M/s ( 1.652M/s/cpu)
uretprobe-nop (48 cpus): 70.544 ± 0.068M/s ( 1.470M/s/cpu)
uretprobe-nop (56 cpus): 74.494 ± 0.055M/s ( 1.330M/s/cpu)
uretprobe-nop (64 cpus): 79.317 ± 0.029M/s ( 1.239M/s/cpu)
uretprobe-nop (72 cpus): 84.875 ± 0.020M/s ( 1.179M/s/cpu)
uretprobe-nop (80 cpus): 92.318 ± 0.224M/s ( 1.154M/s/cpu)
For reference, with uprobe-nop we hit the following throughput:
uprobe-nop (80 cpus): 143.485 ± 0.035M/s ( 1.794M/s/cpu)
So now uretprobe stays a bit closer to that performance.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20241206002417.3295533-5-andrii@kernel.org
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Ensure that by the time we call free_ret_instance() to clean up an
instance of struct return_instance it isn't reachable from
utask->return_instances anymore.
free_ret_instance() is called in a few different situations, all but one
of which already are fine w.r.t. return_instance visibility:
- uprobe_free_utask() guarantees that ri_timer() won't be called
(through timer_delete_sync() call), and so there is no need to
unlink anything, because entire utask is being freed;
- uprobe_handle_trampoline() is already unlinking to-be-freed
return_instance with rcu_assign_pointer() before calling
free_ret_instance().
Only cleanup_return_instances() violates this property, which so far is
not causing problems due to RCU-delayed freeing of return_instance,
which we'll change in the next patch. So make sure we unlink
return_instance before passing it into free_ret_instance(), as otherwise
reuse will be unsafe.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20241206002417.3295533-4-andrii@kernel.org
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free_ret_instance() has two unrelated responsibilities: actually
cleaning up return_instance's resources and freeing memory, and also
helping with utask->return_instances list traversal by returning the
next alive pointer.
There is no reason why these two aspects have to be mixed together, so
turn free_ret_instance() into void-returning function and make callers
do list traversal on their own.
We'll use this simplification in the next patch that will guarantee that
to-be-freed return_instance isn't reachable from utask->return_instances
list.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20241206002417.3295533-3-andrii@kernel.org
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In practice, each return_instance will typically contain either zero or
one return_consumer, depending on whether it has any uprobe session
consumer attached or not. It's highly unlikely that more than one uprobe
session consumers will be attached to any given uprobe, so there is no
need to optimize for that case. But the way we currently do memory
allocation and accounting is by pre-allocating the space for 4 session
consumers in contiguous block of memory next to struct return_instance
fixed part. This is unnecessarily wasteful.
This patch changes this to keep struct return_instance fixed-sized with one
pre-allocated return_consumer, while (in a highly unlikely scenario)
allowing for more session consumers in a separate dynamically
allocated and reallocated array.
We also simplify accounting a bit by not maintaining a separate
temporary capacity for consumers array, and, instead, relying on
krealloc() to be a no-op if underlying memory can accommodate a slightly
bigger allocation (but again, it's very uncommon scenario to even have
to do this reallocation).
All this gets rid of ri_size(), simplifies push_consumer() and removes
confusing ri->consumers_cnt re-assignment, while containing this
singular preallocated consumer logic contained within a few simple
preexisting helpers.
Having fixed-sized struct return_instance simplifies and speeds up
return_instance reuse that we ultimately add later in this patch set,
see follow up patches.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20241206002417.3295533-2-andrii@kernel.org
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Given filp_cachep is marked SLAB_TYPESAFE_BY_RCU (and FMODE_BACKING
files, a special case, now goes through RCU-delated freeing), we can
safely access vma->vm_file->f_inode field locklessly under just
rcu_read_lock() protection, which enables looking up uprobe from
uprobes_tree completely locklessly and speculatively without the need to
acquire mmap_lock for reads. In most cases, anyway, assuming that there
are no parallel mm and/or VMA modifications. The underlying struct
file's memory won't go away from under us (even if struct file can be
reused in the meantime).
We rely on newly added mmap_lock_speculate_{try_begin,retry}() helpers to
validate that mm_struct stays intact for entire duration of this
speculation. If not, we fall back to mmap_lock-protected lookup.
The speculative logic is written in such a way that it will safely
handle any garbage values that might be read from vma or file structs.
Benchmarking results speak for themselves.
BEFORE (latest tip/perf/core)
=============================
uprobe-nop ( 1 cpus): 3.384 ± 0.004M/s ( 3.384M/s/cpu)
uprobe-nop ( 2 cpus): 5.456 ± 0.005M/s ( 2.728M/s/cpu)
uprobe-nop ( 3 cpus): 7.863 ± 0.015M/s ( 2.621M/s/cpu)
uprobe-nop ( 4 cpus): 9.442 ± 0.008M/s ( 2.360M/s/cpu)
uprobe-nop ( 5 cpus): 11.036 ± 0.013M/s ( 2.207M/s/cpu)
uprobe-nop ( 6 cpus): 10.884 ± 0.019M/s ( 1.814M/s/cpu)
uprobe-nop ( 7 cpus): 7.897 ± 0.145M/s ( 1.128M/s/cpu)
uprobe-nop ( 8 cpus): 10.021 ± 0.128M/s ( 1.253M/s/cpu)
uprobe-nop (10 cpus): 9.932 ± 0.170M/s ( 0.993M/s/cpu)
uprobe-nop (12 cpus): 8.369 ± 0.056M/s ( 0.697M/s/cpu)
uprobe-nop (14 cpus): 8.678 ± 0.017M/s ( 0.620M/s/cpu)
uprobe-nop (16 cpus): 7.392 ± 0.003M/s ( 0.462M/s/cpu)
uprobe-nop (24 cpus): 5.326 ± 0.178M/s ( 0.222M/s/cpu)
uprobe-nop (32 cpus): 5.426 ± 0.059M/s ( 0.170M/s/cpu)
uprobe-nop (40 cpus): 5.262 ± 0.070M/s ( 0.132M/s/cpu)
uprobe-nop (48 cpus): 6.121 ± 0.010M/s ( 0.128M/s/cpu)
uprobe-nop (56 cpus): 6.252 ± 0.035M/s ( 0.112M/s/cpu)
uprobe-nop (64 cpus): 7.644 ± 0.023M/s ( 0.119M/s/cpu)
uprobe-nop (72 cpus): 7.781 ± 0.001M/s ( 0.108M/s/cpu)
uprobe-nop (80 cpus): 8.992 ± 0.048M/s ( 0.112M/s/cpu)
AFTER
=====
uprobe-nop ( 1 cpus): 3.534 ± 0.033M/s ( 3.534M/s/cpu)
uprobe-nop ( 2 cpus): 6.701 ± 0.007M/s ( 3.351M/s/cpu)
uprobe-nop ( 3 cpus): 10.031 ± 0.007M/s ( 3.344M/s/cpu)
uprobe-nop ( 4 cpus): 13.003 ± 0.012M/s ( 3.251M/s/cpu)
uprobe-nop ( 5 cpus): 16.274 ± 0.006M/s ( 3.255M/s/cpu)
uprobe-nop ( 6 cpus): 19.563 ± 0.024M/s ( 3.261M/s/cpu)
uprobe-nop ( 7 cpus): 22.696 ± 0.054M/s ( 3.242M/s/cpu)
uprobe-nop ( 8 cpus): 24.534 ± 0.010M/s ( 3.067M/s/cpu)
uprobe-nop (10 cpus): 30.475 ± 0.117M/s ( 3.047M/s/cpu)
uprobe-nop (12 cpus): 33.371 ± 0.017M/s ( 2.781M/s/cpu)
uprobe-nop (14 cpus): 38.864 ± 0.004M/s ( 2.776M/s/cpu)
uprobe-nop (16 cpus): 41.476 ± 0.020M/s ( 2.592M/s/cpu)
uprobe-nop (24 cpus): 64.696 ± 0.021M/s ( 2.696M/s/cpu)
uprobe-nop (32 cpus): 85.054 ± 0.027M/s ( 2.658M/s/cpu)
uprobe-nop (40 cpus): 101.979 ± 0.032M/s ( 2.549M/s/cpu)
uprobe-nop (48 cpus): 110.518 ± 0.056M/s ( 2.302M/s/cpu)
uprobe-nop (56 cpus): 117.737 ± 0.020M/s ( 2.102M/s/cpu)
uprobe-nop (64 cpus): 124.613 ± 0.079M/s ( 1.947M/s/cpu)
uprobe-nop (72 cpus): 133.239 ± 0.032M/s ( 1.851M/s/cpu)
uprobe-nop (80 cpus): 142.037 ± 0.138M/s ( 1.775M/s/cpu)
Previously total throughput was maxing out at 11mln/s, and gradually
declining past 8 cores. With this change, it now keeps growing with each
added CPU, reaching 142mln/s at 80 CPUs (this was measured on a 80-core
Intel(R) Xeon(R) Gold 6138 CPU @ 2.00GHz).
Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20241122035922.3321100-3-andrii@kernel.org
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At the point where find_active_uprobe_rcu() is used we know that VMA in
question has triggered software breakpoint, so we don't need to validate
vma->vm_flags. Keep only vma->vm_file NULL check.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20241122035922.3321100-2-andrii@kernel.org
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- The series "resource: A couple of cleanups" from Andy Shevchenko
performs some cleanups in the resource management code
- The series "Improve the copy of task comm" from Yafang Shao addresses
possible race-induced overflows in the management of
task_struct.comm[]
- The series "Remove unnecessary header includes from
{tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
small fix to the list_sort library code and to its selftest
- The series "Enhance min heap API with non-inline functions and
optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
min_heap library code
- The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
finishes off nilfs2's folioification
- The series "add detect count for hung tasks" from Lance Yang adds
more userspace visibility into the hung-task detector's activity
- Apart from that, singelton patches in many places - please see the
individual changelogs for details
* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
gdb: lx-symbols: do not error out on monolithic build
kernel/reboot: replace sprintf() with sysfs_emit()
lib: util_macros_kunit: add kunit test for util_macros.h
util_macros.h: fix/rework find_closest() macros
Improve consistency of '#error' directive messages
ocfs2: fix uninitialized value in ocfs2_file_read_iter()
hung_task: add docs for hung_task_detect_count
hung_task: add detect count for hung tasks
dma-buf: use atomic64_inc_return() in dma_buf_getfile()
fs/proc/kcore.c: fix coccinelle reported ERROR instances
resource: avoid unnecessary resource tree walking in __region_intersects()
ocfs2: remove unused errmsg function and table
ocfs2: cluster: fix a typo
lib/scatterlist: use sg_phys() helper
checkpatch: always parse orig_commit in fixes tag
nilfs2: convert metadata aops from writepage to writepages
nilfs2: convert nilfs_recovery_copy_block() to take a folio
nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
nilfs2: remove nilfs_writepage
nilfs2: convert checkpoint file to be folio-based
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection
algorithm. This leads to improved memory savings.
- Wei Yang has gone to town on the mapletree code, contributing several
series which clean up the implementation:
- "refine mas_mab_cp()"
- "Reduce the space to be cleared for maple_big_node"
- "maple_tree: simplify mas_push_node()"
- "Following cleanup after introduce mas_wr_store_type()"
- "refine storing null"
- The series "selftests/mm: hugetlb_fault_after_madv improvements" from
David Hildenbrand fixes this selftest for s390.
- The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
implements some rationaizations and cleanups in the page mapping
code.
- The series "mm: optimize shadow entries removal" from Shakeel Butt
optimizes the file truncation code by speeding up the handling of
shadow entries.
- The series "Remove PageKsm()" from Matthew Wilcox completes the
migration of this flag over to being a folio-based flag.
- The series "Unify hugetlb into arch_get_unmapped_area functions" from
Oscar Salvador implements a bunch of consolidations and cleanups in
the hugetlb code.
- The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
takes away the wp-fault time practice of turning a huge zero page
into small pages. Instead we replace the whole thing with a THP. More
consistent cleaner and potentiall saves a large number of pagefaults.
- The series "percpu: Add a test case and fix for clang" from Andy
Shevchenko enhances and fixes the kernel's built in percpu test code.
- The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
optimizes mremap() by avoiding doing things which we didn't need to
do.
- The series "Improve the tmpfs large folio read performance" from
Baolin Wang teaches tmpfs to copy data into userspace at the folio
size rather than as individual pages. A 20% speedup was observed.
- The series "mm/damon/vaddr: Fix issue in
damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
splitting.
- The series "memcg-v1: fully deprecate charge moving" from Shakeel
Butt removes the long-deprecated memcgv2 charge moving feature.
- The series "fix error handling in mmap_region() and refactor" from
Lorenzo Stoakes cleanup up some of the mmap() error handling and
addresses some potential performance issues.
- The series "x86/module: use large ROX pages for text allocations"
from Mike Rapoport teaches x86 to use large pages for
read-only-execute module text.
- The series "page allocation tag compression" from Suren Baghdasaryan
is followon maintenance work for the new page allocation profiling
feature.
- The series "page->index removals in mm" from Matthew Wilcox remove
most references to page->index in mm/. A slow march towards shrinking
struct page.
- The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
interface tests" from Andrew Paniakin performs maintenance work for
DAMON's self testing code.
- The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
improves zswap's batching of compression and decompression. It is a
step along the way towards using Intel IAA hardware acceleration for
this zswap operation.
- The series "kasan: migrate the last module test to kunit" from
Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
tests over to the KUnit framework.
- The series "implement lightweight guard pages" from Lorenzo Stoakes
permits userapace to place fault-generating guard pages within a
single VMA, rather than requiring that multiple VMAs be created for
this. Improved efficiencies for userspace memory allocators are
expected.
- The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
tracepoints to provide increased visibility into memcg stats flushing
activity.
- The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
fixes a zram buglet which potentially affected performance.
- The series "mm: add more kernel parameters to control mTHP" from
Maíra Canal enhances our ability to control/configuremultisize THP
from the kernel boot command line.
- The series "kasan: few improvements on kunit tests" from Sabyrzhan
Tasbolatov has a couple of fixups for the KASAN KUnit tests.
- The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
from Kairui Song optimizes list_lru memory utilization when lockdep
is enabled.
* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
mm/kfence: add a new kunit test test_use_after_free_read_nofault()
zram: fix NULL pointer in comp_algorithm_show()
memcg/hugetlb: add hugeTLB counters to memcg
vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
zram: ZRAM_DEF_COMP should depend on ZRAM
MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
Docs/mm/damon: recommend academic papers to read and/or cite
mm: define general function pXd_init()
kmemleak: iommu/iova: fix transient kmemleak false positive
mm/list_lru: simplify the list_lru walk callback function
mm/list_lru: split the lock to per-cgroup scope
mm/list_lru: simplify reparenting and initial allocation
mm/list_lru: code clean up for reparenting
mm/list_lru: don't export list_lru_add
mm/list_lru: don't pass unnecessary key parameters
kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance events updates from Ingo Molnar:
"Uprobes:
- Add BPF session support (Jiri Olsa)
- Switch to RCU Tasks Trace flavor for better performance (Andrii
Nakryiko)
- Massively increase uretprobe SMP scalability by SRCU-protecting
the uretprobe lifetime (Andrii Nakryiko)
- Kill xol_area->slot_count (Oleg Nesterov)
Core facilities:
- Implement targeted high-frequency profiling by adding the ability
for an event to "pause" or "resume" AUX area tracing (Adrian
Hunter)
VM profiling/sampling:
- Correct perf sampling with guest VMs (Colton Lewis)
New hardware support:
- x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi)
Misc fixes and enhancements:
- x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter)
- x86/amd: Warn only on new bits set (Breno Leitao)
- x86/amd/uncore: Avoid a false positive warning about snprintf
truncation in amd_uncore_umc_ctx_init (Jean Delvare)
- uprobes: Re-order struct uprobe_task to save some space
(Christophe JAILLET)
- x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang)
- x86/rapl: Clean up cpumask and hotplug (Kan Liang)
- uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg
Nesterov)"
* tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
perf/core: Correct perf sampling with guest VMs
perf/x86: Refactor misc flag assignments
perf/powerpc: Use perf_arch_instruction_pointer()
perf/core: Hoist perf_instruction_pointer() and perf_misc_flags()
perf/arm: Drop unused functions
uprobes: Re-order struct uprobe_task to save some space
perf/x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init
perf/x86/intel: Do not enable large PEBS for events with aux actions or aux sampling
perf/x86/intel/pt: Add support for pause / resume
perf/core: Add aux_pause, aux_resume, aux_start_paused
perf/x86/intel/pt: Fix buffer full but size is 0 case
uprobes: SRCU-protect uretprobe lifetime (with timeout)
uprobes: allow put_uprobe() from non-sleepable softirq context
perf/x86/rapl: Clean up cpumask and hotplug
perf/x86/rapl: Move the pmu allocation out of CPU hotplug
uprobe: Add support for session consumer
uprobe: Add data pointer to consumer handlers
perf/x86/amd: Warn only on new bits set
uprobes: fold xol_take_insn_slot() into xol_get_insn_slot()
uprobes: kill xol_area->slot_count
...
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Currently, space for raw sample data is always allocated within sample
records for both BPF output and tracepoint events. This leads to unused
space in sample records when raw sample data is not requested.
This patch enforces checking sample type of an event in
perf_sample_save_raw_data(). So raw sample data will only be saved if
explicitly requested, reducing overhead when it is not needed.
Fixes: 0a9081cf0a11 ("perf/core: Add perf_sample_save_raw_data() helper")
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240515193610.2350456-2-yabinc@google.com
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Pull 'struct fd' class updates from Al Viro:
"The bulk of struct fd memory safety stuff
Making sure that struct fd instances are destroyed in the same scope
where they'd been created, getting rid of reassignments and passing
them by reference, converting to CLASS(fd{,_pos,_raw}).
We are getting very close to having the memory safety of that stuff
trivial to verify"
* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
deal with the last remaing boolean uses of fd_file()
css_set_fork(): switch to CLASS(fd_raw, ...)
memcg_write_event_control(): switch to CLASS(fd)
assorted variants of irqfd setup: convert to CLASS(fd)
do_pollfd(): convert to CLASS(fd)
convert do_select()
convert vfs_dedupe_file_range().
convert cifs_ioctl_copychunk()
convert media_request_get_by_fd()
convert spu_run(2)
switch spufs_calls_{get,put}() to CLASS() use
convert cachestat(2)
convert do_preadv()/do_pwritev()
fdget(), more trivial conversions
fdget(), trivial conversions
privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
o2hb_region_dev_store(): avoid goto around fdget()/fdput()
introduce "fd_pos" class, convert fdget_pos() users to it.
fdget_raw() users: switch to CLASS(fd_raw)
convert vmsplice() to CLASS(fd)
...
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Previously any PMU overflow interrupt that fired while a VCPU was
loaded was recorded as a guest event whether it truly was or not. This
resulted in nonsense perf recordings that did not honor
perf_event_attr.exclude_guest and recorded guest IPs where it should
have recorded host IPs.
Rework the sampling logic to only record guest samples for events with
exclude_guest = 0. This way any host-only events with exclude_guest
set will never see unexpected guest samples. The behaviour of events
with exclude_guest = 0 is unchanged.
Note that events configured to sample both host and guest may still
misattribute a PMI that arrived in the host as a guest event depending
on KVM arch and vendor behavior.
Signed-off-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241113190156.2145593-6-coltonlewis@google.com
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For clarity, rename the arch-specific definitions of these functions
to perf_arch_* to denote they are arch-specifc. Define the
generic-named functions in one place where they can call the
arch-specific ones as needed.
Signed-off-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20241113190156.2145593-3-coltonlewis@google.com
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After introducing the default builtin swap implementation, update the
min_heap_callbacks to replace the swp function pointer with NULL. This
change allows the min heap to directly utilize the builtin swap,
simplifying the code.
Link: https://lkml.kernel.org/r/20241020040200.939973-6-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "Enhance min heap API with non-inline functions and
optimizations", v2.
Add non-inline versions of the min heap API functions in lib/min_heap.c
and updates all users outside of kernel/events/core.c to use these
non-inline versions. To mitigate the performance impact of indirect
function calls caused by the non-inline versions of the swap and compare
functions, a builtin swap has been introduced that swaps elements based on
their size. Additionally, it micro-optimizes the efficiency of the min
heap by pre-scaling the counter, following the same approach as in
lib/sort.c. Documentation for the min heap API has also been added to the
core-api section.
This patch (of 10):
All current min heap API functions are marked with '__always_inline'.
However, as the number of users increases, inlining these functions
everywhere leads to a increase in kernel size.
In performance-critical paths, such as when perf events are enabled and
min heap functions are called on every context switch, it is important to
retain the inline versions for optimal performance. To balance this, the
original inline functions are kept, and additional non-inline versions of
the functions have been added in lib/min_heap.c.
Link: https://lkml.kernel.org/r/20241020040200.939973-1-visitorckw@gmail.com
Link: https://lore.kernel.org/20240522161048.8d8bbc7b153b4ecd92c50666@linux-foundation.org
Link: https://lkml.kernel.org/r/20241020040200.939973-2-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Use ERR_PTR_PCPU() when returning error pointer in the percpu address
space. Use IS_ERR_PCPU() and PTR_ERR_PCPU() when returning the error
pointer from the percpu address space. These macros add intermediate cast
to unsigned long when switching named address spaces.
The patch will avoid future build errors due to pointer address space
mismatch with enabled strict percpu address space checks.
Link: https://lkml.kernel.org/r/20240924090813.1353586-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The types of mm flags are now far beyond the core dump related features.
This patch moves mm flags from linux/sched/coredump.h to linux/mm_types.h.
The linux/sched/coredump.h has include the mm_types.h, so the C files
related to coredump does not need to change head file inclusion. In
addition, the inclusion of sched/coredump.h now can be deleted from the C
files that irrelevant to core dump.
Link: https://lkml.kernel.org/r/20240926074922.2721274-1-sunnanyong@huawei.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Hardware traces, such as instruction traces, can produce a vast amount of
trace data, so being able to reduce tracing to more specific circumstances
can be useful.
The ability to pause or resume tracing when another event happens, can do
that.
Add ability for an event to "pause" or "resume" AUX area tracing.
Add aux_pause bit to perf_event_attr to indicate that, if the event
happens, the associated AUX area tracing should be paused. Ditto
aux_resume. Do not allow aux_pause and aux_resume to be set together.
Add aux_start_paused bit to perf_event_attr to indicate to an AUX area
event that it should start in a "paused" state.
Add aux_paused to struct hw_perf_event for AUX area events to keep track of
the "paused" state. aux_paused is initialized to aux_start_paused.
Add PERF_EF_PAUSE and PERF_EF_RESUME modes for ->stop() and ->start()
callbacks. Call as needed, during __perf_event_output(). Add
aux_in_pause_resume to struct perf_buffer to prevent races with the NMI
handler. Pause/resume in NMI context will miss out if it coincides with
another pause/resume.
To use aux_pause or aux_resume, an event must be in a group with the AUX
area event as the group leader.
Example (requires Intel PT and tools patches also):
$ perf record --kcore -e intel_pt/aux-action=start-paused/k,syscalls:sys_enter_newuname/aux-action=resume/,syscalls:sys_exit_newuname/aux-action=pause/ uname
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.043 MB perf.data ]
$ perf script --call-trace
uname 30805 [000] 24001.058782799: name: 0x7ffc9c1865b0
uname 30805 [000] 24001.058784424: psb offs: 0
uname 30805 [000] 24001.058784424: cbr: 39 freq: 3904 MHz (139%)
uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) debug_smp_processor_id
uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) __x64_sys_newuname
uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) down_read
uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) __cond_resched
uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) preempt_count_add
uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) in_lock_functions
uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) preempt_count_sub
uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) up_read
uname 30805 [000] 24001.058784629: ([kernel.kallsyms]) preempt_count_add
uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) in_lock_functions
uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) preempt_count_sub
uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) _copy_to_user
uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) syscall_exit_to_user_mode
uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) syscall_exit_work
uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) perf_syscall_exit
uname 30805 [000] 24001.058784838: ([kernel.kallsyms]) debug_smp_processor_id
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_trace_buf_alloc
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_swevent_get_recursion_context
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) debug_smp_processor_id
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) debug_smp_processor_id
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_tp_event
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_trace_buf_update
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) tracing_gen_ctx_irq_test
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_swevent_event
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) __perf_event_account_interrupt
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) __this_cpu_preempt_check
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_event_output_forward
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) perf_event_aux_pause
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) ring_buffer_get
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) __rcu_read_lock
uname 30805 [000] 24001.058785046: ([kernel.kallsyms]) __rcu_read_unlock
uname 30805 [000] 24001.058785254: ([kernel.kallsyms]) pt_event_stop
uname 30805 [000] 24001.058785254: ([kernel.kallsyms]) debug_smp_processor_id
uname 30805 [000] 24001.058785254: ([kernel.kallsyms]) debug_smp_processor_id
uname 30805 [000] 24001.058785254: ([kernel.kallsyms]) native_write_msr
uname 30805 [000] 24001.058785463: ([kernel.kallsyms]) native_write_msr
uname 30805 [000] 24001.058785639: 0x0
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: James Clark <james.clark@arm.com>
Link: https://lkml.kernel.org/r/20241022155920.17511-3-adrian.hunter@intel.com
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fdget() is the first thing done in scope, all matching fdput() are
immediately followed by leaving the scope.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Lift fdget() and fdput() out of perf_fget_light(), turning it into
is_perf_file(struct fd f). The life gets easier in both callers
if we do fdget() unconditionally, including the case when we are
given -1 instead of a descriptor - that avoids a reassignment in
perf_event_open(2) and it avoids a nasty temptation in _perf_ioctl()
where we must *not* lift output_event out of scope for output.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Avoid taking refcount on uprobe in prepare_uretprobe(), instead take
uretprobe-specific SRCU lock and keep it active as kernel transfers
control back to user space.
Given we can't rely on user space returning from traced function within
reasonable time period, we need to make sure not to keep SRCU lock
active for too long, though. To that effect, we employ a timer callback
which is meant to terminate SRCU lock region after predefined timeout
(currently set to 100ms), and instead transfer underlying struct
uprobe's lifetime protection to refcounting.
This fallback to less scalable refcounting after 100ms is a fine
tradeoff from uretprobe's scalability and performance perspective,
because uretprobing *long running* user functions inherently doesn't run
into scalability issues (there is just not enough frequency to cause
noticeable issues with either performance or scalability).
The overall trick is in ensuring synchronization between current thread
and timer's callback fired on some other thread. To cope with that with
minimal logic complications, we add hprobe wrapper which is used to
contain all the synchronization related issues behind a small number of
basic helpers: hprobe_expire() for "downgrading" uprobe from SRCU-protected
state to refcounted state, and a hprobe_consume() and hprobe_finalize()
pair of single-use consuming helpers. Other than that, whatever current
thread's logic is there stays the same, as timer thread cannot modify
return_instance state (or add new/remove old return_instances). It only
takes care of SRCU unlock and uprobe refcounting, which is hidden from
the higher-level uretprobe handling logic.
We use atomic xchg() in hprobe_consume(), which is called from
performance critical handle_uretprobe_chain() function run in the
current context. When uncontended, this xchg() doesn't seem to hurt
performance as there are no other competing CPUs fighting for the same
cache line. We also mark struct return_instance as ____cacheline_aligned
to ensure no false sharing can happen.
Another technical moment. We need to make sure that the list of return
instances can be safely traversed under RCU from timer callback, so we
delay return_instance freeing with kfree_rcu() and make sure that list
modifications use RCU-aware operations.
Also, given SRCU lock survives transition from kernel to user space and
back we need to use lower-level __srcu_read_lock() and
__srcu_read_unlock() to avoid lockdep complaining.
Just to give an impression of a kind of performance improvements this
change brings, below are benchmarking results with and without these
SRCU changes, assuming other uprobe optimizations (mainly RCU Tasks
Trace for entry uprobes, lockless RB-tree lookup, and lockless VMA to
uprobe lookup) are left intact:
WITHOUT SRCU for uretprobes
===========================
uretprobe-nop ( 1 cpus): 2.197 ± 0.002M/s ( 2.197M/s/cpu)
uretprobe-nop ( 2 cpus): 3.325 ± 0.001M/s ( 1.662M/s/cpu)
uretprobe-nop ( 3 cpus): 4.129 ± 0.002M/s ( 1.376M/s/cpu)
uretprobe-nop ( 4 cpus): 6.180 ± 0.003M/s ( 1.545M/s/cpu)
uretprobe-nop ( 8 cpus): 7.323 ± 0.005M/s ( 0.915M/s/cpu)
uretprobe-nop (16 cpus): 6.943 ± 0.005M/s ( 0.434M/s/cpu)
uretprobe-nop (32 cpus): 5.931 ± 0.014M/s ( 0.185M/s/cpu)
uretprobe-nop (64 cpus): 5.145 ± 0.003M/s ( 0.080M/s/cpu)
uretprobe-nop (80 cpus): 4.925 ± 0.005M/s ( 0.062M/s/cpu)
WITH SRCU for uretprobes
========================
uretprobe-nop ( 1 cpus): 1.968 ± 0.001M/s ( 1.968M/s/cpu)
uretprobe-nop ( 2 cpus): 3.739 ± 0.003M/s ( 1.869M/s/cpu)
uretprobe-nop ( 3 cpus): 5.616 ± 0.003M/s ( 1.872M/s/cpu)
uretprobe-nop ( 4 cpus): 7.286 ± 0.002M/s ( 1.822M/s/cpu)
uretprobe-nop ( 8 cpus): 13.657 ± 0.007M/s ( 1.707M/s/cpu)
uretprobe-nop (32 cpus): 45.305 ± 0.066M/s ( 1.416M/s/cpu)
uretprobe-nop (64 cpus): 42.390 ± 0.922M/s ( 0.662M/s/cpu)
uretprobe-nop (80 cpus): 47.554 ± 2.411M/s ( 0.594M/s/cpu)
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241024044159.3156646-3-andrii@kernel.org
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Currently put_uprobe() might trigger mutex_lock()/mutex_unlock(), which
makes it unsuitable to be called from more restricted context like softirq.
Let's make put_uprobe() agnostic to the context in which it is called,
and use work queue to defer the mutex-protected clean up steps.
RB tree removal step is also moved into work-deferred callback to avoid
potential deadlock between softirq-based timer callback, added in the
next patch, and the rest of uprobe code.
We can rework locking altogher as a follow up, but that's significantly
more tricky, so warrants its own patch set. For now, we need to make
sure that changes in the next patch that add timer thread work correctly
with existing approach, while concentrating on SRCU + timeout logic.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241024044159.3156646-2-andrii@kernel.org
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This change allows the uprobe consumer to behave as session which
means that 'handler' and 'ret_handler' callbacks are connected in
a way that allows to:
- control execution of 'ret_handler' from 'handler' callback
- share data between 'handler' and 'ret_handler' callbacks
The session concept fits to our common use case where we do filtering
on entry uprobe and based on the result we decide to run the return
uprobe (or not).
It's also convenient to share the data between session callbacks.
To achive this we are adding new return value the uprobe consumer
can return from 'handler' callback:
UPROBE_HANDLER_IGNORE
- Ignore 'ret_handler' callback for this consumer.
And store cookie and pass it to 'ret_handler' when consumer has both
'handler' and 'ret_handler' callbacks defined.
We store shared data in the return_consumer object array as part of
the return_instance object. This way the handle_uretprobe_chain can
find related return_consumer and its shared data.
We also store entry handler return value, for cases when there are
multiple consumers on single uprobe and some of them are ignored and
some of them not, in which case the return probe gets installed and
we need to have a way to find out which consumer needs to be ignored.
The tricky part is when consumer is registered 'after' the uprobe
entry handler is hit. In such case this consumer's 'ret_handler' gets
executed as well, but it won't have the proper data pointer set,
so we can filter it out.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241018202252.693462-3-jolsa@kernel.org
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Adding data pointer to both entry and exit consumer handlers and all
its users. The functionality itself is coming in following change.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241018202252.693462-2-jolsa@kernel.org
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Running rcutorture scenario TREE05, the below warning is triggered.
[ 32.604594] WARNING: suspicious RCU usage
[ 32.605928] 6.11.0-rc5-00040-g4ba4f1afb6a9 #55238 Not tainted
[ 32.607812] -----------------------------
[ 32.609140] kernel/events/core.c:13946 RCU-list traversed in non-reader section!!
[ 32.611595] other info that might help us debug this:
[ 32.614247] rcu_scheduler_active = 2, debug_locks = 1
[ 32.616392] 3 locks held by cpuhp/4/35:
[ 32.617687] #0: ffffffffb666a650 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x4e/0x200
[ 32.620563] #1: ffffffffb666cd20 (cpuhp_state-down){+.+.}-{0:0}, at: cpuhp_thread_fun+0x4e/0x200
[ 32.623412] #2: ffffffffb677c288 (pmus_lock){+.+.}-{3:3}, at: perf_event_exit_cpu_context+0x32/0x2f0
In perf_event_clear_cpumask(), uses list_for_each_entry_rcu() without an
obvious RCU read-side critical section.
Either pmus_srcu or pmus_lock is good enough to protect the pmus list.
In the current context, pmus_lock is already held. The
list_for_each_entry_rcu() is not required.
Fixes: 4ba4f1afb6a9 ("perf: Generic hotplug support for a PMU with a scope")
Closes: https://lore.kernel.org/lkml/2b66dff8-b827-494b-b151-1ad8d56f13e6@paulmck-laptop/
Closes: https://lore.kernel.org/oe-lkp/202409131559.545634cc-oliver.sang@intel.com
Reported-by: "Paul E. McKenney" <paulmck@kernel.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: "Paul E. McKenney" <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240913162340.2142976-1-kan.liang@linux.intel.com
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Sean noted that ever since commit 152e11f6df29 ("sched/fair: Implement
delayed dequeue") KVM's preemption notifiers have started
mis-classifying preemption vs blocking.
Notably p->on_rq is no longer sufficient to determine if a task is
runnable or blocked -- the aforementioned commit introduces tasks that
remain on the runqueue even through they will not run again, and
should be considered blocked for many cases.
Add the task_is_runnable() helper to classify things and audit all
external users of the p->on_rq state. Also add a few comments.
Fixes: 152e11f6df29 ("sched/fair: Implement delayed dequeue")
Reported-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20241010091843.GK33184@noisy.programming.kicks-ass.net
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After the previous change xol_take_insn_slot() becomes trivial, kill it.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241001142503.GA13633@redhat.com
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Add the new helper, xol_get_slot_nr() which does
find_first_zero_bit() + test_and_set_bit().
xol_take_insn_slot() can wait for the "xol_get_slot_nr() < UINSNS_PER_PAGE"
event instead of "area->slot_count < UINSNS_PER_PAGE".
So we can kill area->slot_count and avoid atomic_inc() + atomic_dec(), this
simplifies the code and can slightly improve the performance.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241001142458.GA13629@redhat.com
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kernel/events/uprobes.c assumes that xol_area->vaddr is always correct but
a malicious application can remap its "[uprobes]" vma to another adress to
confuse the kernel. Introduce xol_mremap() to make this impossible.
With this change utask->xol_vaddr in xol_free_insn_slot() can't be invalid,
we can turn the offset check into WARN_ON_ONCE(offset >= PAGE_SIZE).
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144258.GA9492@redhat.com
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Add the "struct uprobe_task *utask" argument to xol_get_insn_slot() and
xol_free_insn_slot(), their callers already have it so we can avoid the
unnecessary dereference and simplify the code.
Kill the "tsk" argument of xol_free_insn_slot(), it is always current.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144253.GA9487@redhat.com
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xol_get_insn_slot()
This simplifies the code and makes xol_get_insn_slot() symmetric with
xol_free_insn_slot() which clears utask->xol_vaddr.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144248.GA9483@redhat.com
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The do / while (slot_nr >= UINSNS_PER_PAGE) loop in xol_take_insn_slot()
makes no sense, the checked condition is always true. Change this code
to use the "for (;;)" loop, this way we do not need to change slot_nr if
test_and_set_bit() fails.
Also, kill the unnecessary xol_vaddr != NULL check in xol_get_insn_slot(),
xol_take_insn_slot() never returns NULL.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144244.GA9480@redhat.com
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uprobe_free_utask()
If pre_ssout() succeeds and sets utask->active_uprobe and utask->xol_vaddr
the task must not exit until it calls handle_singlestep() which does the
necessary put_uprobe() and xol_free_insn_slot().
Remove put_uprobe() and xol_free_insn_slot() from uprobe_free_utask(). With
this change xol_free_insn_slot() can't hit xol_area/utask/xol_vaddr == NULL,
we can kill the unnecessary checks checks and simplify this function more.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144239.GA9475@redhat.com
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1. Clear utask->xol_vaddr unconditionally, even if this addr is not valid,
xol_free_insn_slot() should never return with utask->xol_vaddr != NULL.
2. Add a comment to explain why do we need to validate slot_addr.
3. Simplify the validation above. We can simply check offset < PAGE_SIZE,
unsigned underflows are fine, it should work if slot_addr < area->vaddr.
4. Kill the unnecessary "slot_nr >= UINSNS_PER_PAGE" check, slot_nr must
be valid if offset < PAGE_SIZE.
The next patches will cleanup this function even more.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144235.GA9471@redhat.com
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handle_swbp() calls get_utask() before prepare_uretprobe() or pre_ssout()
can be called, they can simply use current->utask which can't be NULL.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144230.GA9468@redhat.com
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This patch switches uprobes SRCU usage to RCU Tasks Trace flavor, which
is optimized for more lightweight and quick readers (at the expense of
slower writers, which for uprobes is a fine tradeof) and has better
performance and scalability with number of CPUs.
Similarly to baseline vs SRCU, we've benchmarked SRCU-based
implementation vs RCU Tasks Trace implementation.
SRCU
====
uprobe-nop ( 1 cpus): 3.276 ± 0.005M/s ( 3.276M/s/cpu)
uprobe-nop ( 2 cpus): 4.125 ± 0.002M/s ( 2.063M/s/cpu)
uprobe-nop ( 4 cpus): 7.713 ± 0.002M/s ( 1.928M/s/cpu)
uprobe-nop ( 8 cpus): 8.097 ± 0.006M/s ( 1.012M/s/cpu)
uprobe-nop (16 cpus): 6.501 ± 0.056M/s ( 0.406M/s/cpu)
uprobe-nop (32 cpus): 4.398 ± 0.084M/s ( 0.137M/s/cpu)
uprobe-nop (64 cpus): 6.452 ± 0.000M/s ( 0.101M/s/cpu)
uretprobe-nop ( 1 cpus): 2.055 ± 0.001M/s ( 2.055M/s/cpu)
uretprobe-nop ( 2 cpus): 2.677 ± 0.000M/s ( 1.339M/s/cpu)
uretprobe-nop ( 4 cpus): 4.561 ± 0.003M/s ( 1.140M/s/cpu)
uretprobe-nop ( 8 cpus): 5.291 ± 0.002M/s ( 0.661M/s/cpu)
uretprobe-nop (16 cpus): 5.065 ± 0.019M/s ( 0.317M/s/cpu)
uretprobe-nop (32 cpus): 3.622 ± 0.003M/s ( 0.113M/s/cpu)
uretprobe-nop (64 cpus): 3.723 ± 0.002M/s ( 0.058M/s/cpu)
RCU Tasks Trace
===============
uprobe-nop ( 1 cpus): 3.396 ± 0.002M/s ( 3.396M/s/cpu)
uprobe-nop ( 2 cpus): 4.271 ± 0.006M/s ( 2.135M/s/cpu)
uprobe-nop ( 4 cpus): 8.499 ± 0.015M/s ( 2.125M/s/cpu)
uprobe-nop ( 8 cpus): 10.355 ± 0.028M/s ( 1.294M/s/cpu)
uprobe-nop (16 cpus): 7.615 ± 0.099M/s ( 0.476M/s/cpu)
uprobe-nop (32 cpus): 4.430 ± 0.007M/s ( 0.138M/s/cpu)
uprobe-nop (64 cpus): 6.887 ± 0.020M/s ( 0.108M/s/cpu)
uretprobe-nop ( 1 cpus): 2.174 ± 0.001M/s ( 2.174M/s/cpu)
uretprobe-nop ( 2 cpus): 2.853 ± 0.001M/s ( 1.426M/s/cpu)
uretprobe-nop ( 4 cpus): 4.913 ± 0.002M/s ( 1.228M/s/cpu)
uretprobe-nop ( 8 cpus): 5.883 ± 0.002M/s ( 0.735M/s/cpu)
uretprobe-nop (16 cpus): 5.147 ± 0.001M/s ( 0.322M/s/cpu)
uretprobe-nop (32 cpus): 3.738 ± 0.008M/s ( 0.117M/s/cpu)
uretprobe-nop (64 cpus): 4.397 ± 0.002M/s ( 0.069M/s/cpu)
Peak throughput for uprobes increases from 8 mln/s to 10.3 mln/s
(+28%!), and for uretprobes from 5.3 mln/s to 5.8 mln/s (+11%), as we
have more work to do on uretprobes side.
Even single-thread (no contention) performance is slightly better: 3.276
mln/s to 3.396 mln/s (+3.5%) for uprobes, and 2.055 mln/s to 2.174 mln/s
(+5.8%) for uretprobes.
We also select TASKS_TRACE_RCU for UPROBES in Kconfig due to the new
dependency.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20240910174312.3646590-1-andrii@kernel.org
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xol_add_vma() maps the uninitialized page allocated by __create_xol_area()
into userspace. On some architectures (x86) this memory is readable even
without VM_READ, VM_EXEC results in the same pgprot_t as VM_EXEC|VM_READ,
although this doesn't really matter, debugger can read this memory anyway.
Link: https://lore.kernel.org/all/20240929162047.GA12611@redhat.com/
Reported-by: Will Deacon <will@kernel.org>
Fixes: d4b3b6384f98 ("uprobes/core: Allocate XOL slots for uprobes use")
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull 'struct fd' updates from Al Viro:
"Just the 'struct fd' layout change, with conversion to accessor
helpers"
* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
add struct fd constructors, get rid of __to_fd()
struct fd: representation change
introduce fd_file(), convert all accessors to it.
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The below warning is triggered when building with arm
multi_v7_defconfig.
kernel/events/core.c: In function 'perf_event_setup_cpumask':
kernel/events/core.c:14012:13: warning: the comparison will always evaluate as 'true' for the address of 'thread_sibling' will never be NULL [-Waddress]
14012 | if (!topology_sibling_cpumask(cpu)) {
The perf_event_init_cpu() may be invoked at the early boot stage, while
the topology_*_cpumask hasn't been initialized yet. The check is to
specially handle the case, and initialize the perf_online_<domain>_masks
on the boot CPU.
X86 uses a per-cpu cpumask pointer, which could be NULL at the early
boot stage. However, ARM uses a global variable, which never be NULL.
Use perf_online_mask as an indicator instead. Only initialize the
perf_online_<domain>_masks when perf_online_mask is empty.
Fix a typo as well.
Fixes: 4ba4f1afb6a9 ("perf: Generic hotplug support for a PMU with a scope")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/lkml/20240911153854.240bbc1f@canb.auug.org.au/
Reported-by: Steven Price <steven.price@arm.com>
Closes: https://lore.kernel.org/lkml/1835eb6d-3e05-47f3-9eae-507ce165c3bf@arm.com/
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Steven Price <steven.price@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Introduce '__attribute__((bpf_fastcall))' for helpers and kfuncs with
corresponding support in LLVM.
It is similar to existing 'no_caller_saved_registers' attribute in
GCC/LLVM with a provision for backward compatibility. It allows
compilers generate more efficient BPF code assuming the verifier or
JITs will inline or partially inline a helper/kfunc with such
attribute. bpf_cast_to_kern_ctx, bpf_rdonly_cast,
bpf_get_smp_processor_id are the first set of such helpers.
- Harden and extend ELF build ID parsing logic.
When called from sleepable context the relevants parts of ELF file
will be read to find and fetch .note.gnu.build-id information. Also
harden the logic to avoid TOCTOU, overflow, out-of-bounds problems.
- Improvements and fixes for sched-ext:
- Allow passing BPF iterators as kfunc arguments
- Make the pointer returned from iter_next method trusted
- Fix x86 JIT convergence issue due to growing/shrinking conditional
jumps in variable length encoding
- BPF_LSM related:
- Introduce few VFS kfuncs and consolidate them in
fs/bpf_fs_kfuncs.c
- Enforce correct range of return values from certain LSM hooks
- Disallow attaching to other LSM hooks
- Prerequisite work for upcoming Qdisc in BPF:
- Allow kptrs in program provided structs
- Support for gen_epilogue in verifier_ops
- Important fixes:
- Fix uprobe multi pid filter check
- Fix bpf_strtol and bpf_strtoul helpers
- Track equal scalars history on per-instruction level
- Fix tailcall hierarchy on x86 and arm64
- Fix signed division overflow to prevent INT_MIN/-1 trap on x86
- Fix get kernel stack in BPF progs attached to tracepoint:syscall
- Selftests:
- Add uprobe bench/stress tool
- Generate file dependencies to drastically improve re-build time
- Match JIT-ed and BPF asm with __xlated/__jited keywords
- Convert older tests to test_progs framework
- Add support for RISC-V
- Few fixes when BPF programs are compiled with GCC-BPF backend
(support for GCC-BPF in BPF CI is ongoing in parallel)
- Add traffic monitor
- Enable cross compile and musl libc
* tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (260 commits)
btf: require pahole 1.21+ for DEBUG_INFO_BTF with default DWARF version
btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug
btf: remove redundant CONFIG_BPF test in scripts/link-vmlinux.sh
bpf: Call the missed kfree() when there is no special field in btf
bpf: Call the missed btf_record_free() when map creation fails
selftests/bpf: Add a test case to write mtu result into .rodata
selftests/bpf: Add a test case to write strtol result into .rodata
selftests/bpf: Rename ARG_PTR_TO_LONG test description
selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test
bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error
bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types
bpf: Fix helper writes to read-only maps
bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers
bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit
selftests/bpf: Add tests for sdiv/smod overflow cases
bpf: Fix a sdiv overflow issue
libbpf: Add bpf_object__token_fd accessor
docs/bpf: Add missing BPF program types to docs
docs/bpf: Add constant values for linkages
bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Along with the usual shower of singleton patches, notable patch series
in this pull request are:
- "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
consistency to the APIs and behaviour of these two core allocation
functions. This also simplifies/enables Rustification.
- "Some cleanups for shmem" from Baolin Wang. No functional changes -
mode code reuse, better function naming, logic simplifications.
- "mm: some small page fault cleanups" from Josef Bacik. No
functional changes - code cleanups only.
- "Various memory tiering fixes" from Zi Yan. A small fix and a
little cleanup.
- "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
simplifications and .text shrinkage.
- "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
Butt. This is a feature, it adds new feilds to /proc/vmstat such as
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
which tells us that 11391 processes used 4k of stack while none at
all used 16k. Useful for some system tuning things, but
partivularly useful for "the dynamic kernel stack project".
- "kmemleak: support for percpu memory leak detect" from Pavel
Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.
- "mm: memcg: page counters optimizations" from Roman Gushchin. "3
independent small optimizations of page counters".
- "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
David Hildenbrand. Improves PTE/PMD splitlock detection, makes
powerpc/8xx work correctly by design rather than by accident.
- "mm: remove arch_make_page_accessible()" from David Hildenbrand.
Some folio conversions which make arch_make_page_accessible()
unneeded.
- "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
Finkel. Cleans up and fixes our handling of the resetting of the
cgroup/process peak-memory-use detector.
- "Make core VMA operations internal and testable" from Lorenzo
Stoakes. Rationalizaion and encapsulation of the VMA manipulation
APIs. With a view to better enable testing of the VMA functions,
even from a userspace-only harness.
- "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
issues in the zswap global shrinker, resulting in improved
performance.
- "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
in some missing info in /proc/zoneinfo.
- "mm: replace follow_page() by folio_walk" from David Hildenbrand.
Code cleanups and rationalizations (conversion to folio_walk())
resulting in the removal of follow_page().
- "improving dynamic zswap shrinker protection scheme" from Nhat
Pham. Some tuning to improve zswap's dynamic shrinker. Significant
reductions in swapin and improvements in performance are shown.
- "mm: Fix several issues with unaccepted memory" from Kirill
Shutemov. Improvements to the new unaccepted memory feature,
- "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
DAX PUDs. This was missing, although nobody seems to have notied
yet.
- "Introduce a store type enum for the Maple tree" from Sidhartha
Kumar. Cleanups and modest performance improvements for the maple
tree library code.
- "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
more cgroup v1 remnants away from the v2 memcg code.
- "memcg: initiate deprecation of v1 features" from Shakeel Butt.
Adds various warnings telling users that memcg v1 features are
deprecated.
- "mm: swap: mTHP swap allocator base on swap cluster order" from
Chris Li. Greatly improves the success rate of the mTHP swap
allocation.
- "mm: introduce numa_memblks" from Mike Rapoport. Moves various
disparate per-arch implementations of numa_memblk code into generic
code.
- "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
improves the performance of munmap() of swap-filled ptes.
- "support large folio swap-out and swap-in for shmem" from Baolin
Wang. With this series we no longer split shmem large folios into
simgle-page folios when swapping out shmem.
- "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
performance improvements and code reductions for gigantic folios.
- "support shmem mTHP collapse" from Baolin Wang. Adds support for
khugepaged's collapsing of shmem mTHP folios.
- "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
performance regression due to the addition of mseal().
- "Increase the number of bits available in page_type" from Matthew
Wilcox. Increases the number of bits available in page_type!
- "Simplify the page flags a little" from Matthew Wilcox. Many legacy
page flags are now folio flags, so the page-based flags and their
accessors/mutators can be removed.
- "mm: store zero pages to be swapped out in a bitmap" from Usama
Arif. An optimization which permits us to avoid writing/reading
zero-filled zswap pages to backing store.
- "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
window which occurs when a MAP_FIXED operqtion is occurring during
an unrelated vma tree walk.
- "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
the vma_merge() functionality, making ot cleaner, more testable and
better tested.
- "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
Minor fixups of DAMON selftests and kunit tests.
- "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
Code cleanups and folio conversions.
- "Shmem mTHP controls and stats improvements" from Ryan Roberts.
Cleanups for shmem controls and stats.
- "mm: count the number of anonymous THPs per size" from Barry Song.
Expose additional anon THP stats to userspace for improved tuning.
- "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
folio conversions and removal of now-unused page-based APIs.
- "replace per-quota region priorities histogram buffer with
per-context one" from SeongJae Park. DAMON histogram
rationalization.
- "Docs/damon: update GitHub repo URLs and maintainer-profile" from
SeongJae Park. DAMON documentation updates.
- "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
improve related doc and warn" from Jason Wang: fixes usage of page
allocator __GFP_NOFAIL and GFP_ATOMIC flags.
- "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
This was overprovisioning THPs in sparsely accessed memory areas.
- "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
Add support for zram run-time compression algorithm tuning.
- "mm: Care about shadow stack guard gap when getting an unmapped
area" from Mark Brown. Fix up the various arch_get_unmapped_area()
implementations to better respect guard areas.
- "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
of mem_cgroup_iter() and various code cleanups.
- "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
pfnmap support.
- "resource: Fix region_intersects() vs add_memory_driver_managed()"
from Huang Ying. Fix a bug in region_intersects() for systems with
CXL memory.
- "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
a couple more code paths to correctly recover from the encountering
of poisoned memry.
- "mm: enable large folios swap-in support" from Barry Song. Support
the swapin of mTHP memory into appropriately-sized folios, rather
than into single-page folios"
* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
zram: free secondary algorithms names
uprobes: turn xol_area->pages[2] into xol_area->page
uprobes: introduce the global struct vm_special_mapping xol_mapping
Revert "uprobes: use vm_special_mapping close() functionality"
mm: support large folios swap-in for sync io devices
mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
set_memory: add __must_check to generic stubs
mm/vma: return the exact errno in vms_gather_munmap_vmas()
memcg: cleanup with !CONFIG_MEMCG_V1
mm/show_mem.c: report alloc tags in human readable units
mm: support poison recovery from copy_present_page()
mm: support poison recovery from do_cow_fault()
resource, kunit: add test case for region_intersects()
resource: make alloc_free_mem_region() works for iomem_resource
mm: z3fold: deprecate CONFIG_Z3FOLD
vfio/pci: implement huge_fault support
mm/arm64: support large pfn mappings
mm/x86: support large pfn mappings
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events updates from Ingo Molnar:
- Implement per-PMU context rescheduling to significantly improve
single-PMU performance, and related cleanups/fixes (Peter Zijlstra
and Namhyung Kim)
- Fix ancient bug resulting in a lot of events being dropped
erroneously at higher sampling frequencies (Luo Gengkun)
- uprobes enhancements:
- Implement RCU-protected hot path optimizations for better
performance:
"For baseline vs SRCU, peak througput increased from 3.7 M/s
(million uprobe triggerings per second) up to about 8 M/s. For
uretprobes it's a bit more modest with bump from 2.4 M/s to
5 M/s.
For SRCU vs RCU Tasks Trace, peak throughput for uprobes
increases further from 8 M/s to 10.3 M/s (+28%!), and for
uretprobes from 5.3 M/s to 5.8 M/s (+11%), as we have more
work to do on uretprobes side.
Even single-thread (no contention) performance is slightly
better: 3.276 M/s to 3.396 M/s (+3.5%) for uprobes, and 2.055
M/s to 2.174 M/s (+5.8%) for uretprobes."
(Andrii Nakryiko et al)
- Document mmap_lock, don't abuse get_user_pages_remote() (Oleg
Nesterov)
- Cleanups & fixes to prepare for future work:
- Remove uprobe_register_refctr()
- Simplify error handling for alloc_uprobe()
- Make uprobe_register() return struct uprobe *
- Fold __uprobe_unregister() into uprobe_unregister()
- Shift put_uprobe() from delete_uprobe() to uprobe_unregister()
- BPF: Fix use-after-free in bpf_uprobe_multi_link_attach()
(Oleg Nesterov)
- New feature & ABI extension: allow events to use PERF_SAMPLE READ
with inheritance, enabling sample based profiling of a group of
counters over a hierarchy of processes or threads (Ben Gainey)
- Intel uncore & power events updates:
- Add Arrow Lake and Lunar Lake support
- Add PERF_EV_CAP_READ_SCOPE
- Clean up and enhance cpumask and hotplug support
(Kan Liang)
- Add LNL uncore iMC freerunning support
- Use D0:F0 as a default device
(Zhenyu Wang)
- Intel PT: fix AUX snapshot handling race (Adrian Hunter)
- Misc fixes and cleanups (James Clark, Jiri Olsa, Oleg Nesterov and
Peter Zijlstra)
* tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
dmaengine: idxd: Clean up cpumask and hotplug for perfmon
iommu/vt-d: Clean up cpumask and hotplug for perfmon
perf/x86/intel/cstate: Clean up cpumask and hotplug
perf: Add PERF_EV_CAP_READ_SCOPE
perf: Generic hotplug support for a PMU with a scope
uprobes: perform lockless SRCU-protected uprobes_tree lookup
rbtree: provide rb_find_rcu() / rb_find_add_rcu()
perf/uprobe: split uprobe_unregister()
uprobes: travers uprobe's consumer list locklessly under SRCU protection
uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks
uprobes: protected uprobe lifetime with SRCU
uprobes: revamp uprobe refcounting and lifetime management
bpf: Fix use-after-free in bpf_uprobe_multi_link_attach()
perf/core: Fix small negative period being ignored
perf: Really fix event_function_call() locking
perf: Optimize __pmu_ctx_sched_out()
perf: Add context time freeze
perf: Fix event_function_call() locking
perf: Extract a few helpers
perf: Optimize context reschedule for single PMU cases
...
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Now that xol_mapping has its own ->fault() method we no longer need
xol_area->pages[1] == NULL, we need a single page.
Link: https://lkml.kernel.org/r/20240911131437.GC3448@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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