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synchronize_rcu() users have to be processed regardless
of memory pressure so our private WQ needs to have at least
one execution context what WQ_MEM_RECLAIM flag guarantees.
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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This patch introduces a small enhancement which allows to do a
direct wake-up of synchronize_rcu() callers. It occurs after a
completion of grace period, thus by the gp-kthread.
Number of clients is limited by the hard-coded maximum allowed
threshold. The remaining part, if still exists is deferred to
a main worker.
Link: https://lore.kernel.org/lkml/Zd0ZtNu+Rt0qXkfS@lothringen/
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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Add an rcu_sr_normal() trace event. It takes three arguments
first one is the name of RCU flavour, second one is a user id
which triggeres synchronize_rcu_normal() and last one is an
event.
There are two traces in the synchronize_rcu_normal(). On entry,
when a new request is registered and on exit point when request
is completed.
Please note, CONFIG_RCU_TRACE=y is required to activate traces.
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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A call to a synchronize_rcu() can be optimized from a latency
point of view. Workloads which depend on this can benefit of it.
The delay of wakeme_after_rcu() callback, which unblocks a waiter,
depends on several factors:
- how fast a process of offloading is started. Combination of:
- !CONFIG_RCU_NOCB_CPU/CONFIG_RCU_NOCB_CPU;
- !CONFIG_RCU_LAZY/CONFIG_RCU_LAZY;
- other.
- when started, invoking path is interrupted due to:
- time limit;
- need_resched();
- if limit is reached.
- where in a nocb list it is located;
- how fast previous callbacks completed;
Example:
1. On our embedded devices i can easily trigger the scenario when
it is a last in the list out of ~3600 callbacks:
<snip>
<...>-29 [001] d..1. 21950.145313: rcu_batch_start: rcu_preempt CBs=3613 bl=28
...
<...>-29 [001] ..... 21950.152578: rcu_invoke_callback: rcu_preempt rhp=00000000b2d6dee8 func=__free_vm_area_struct.cfi_jt
<...>-29 [001] ..... 21950.152579: rcu_invoke_callback: rcu_preempt rhp=00000000a446f607 func=__free_vm_area_struct.cfi_jt
<...>-29 [001] ..... 21950.152580: rcu_invoke_callback: rcu_preempt rhp=00000000a5cab03b func=__free_vm_area_struct.cfi_jt
<...>-29 [001] ..... 21950.152581: rcu_invoke_callback: rcu_preempt rhp=0000000013b7e5ee func=__free_vm_area_struct.cfi_jt
<...>-29 [001] ..... 21950.152582: rcu_invoke_callback: rcu_preempt rhp=000000000a8ca6f9 func=__free_vm_area_struct.cfi_jt
<...>-29 [001] ..... 21950.152583: rcu_invoke_callback: rcu_preempt rhp=000000008f162ca8 func=wakeme_after_rcu.cfi_jt
<...>-29 [001] d..1. 21950.152625: rcu_batch_end: rcu_preempt CBs-invoked=3612 idle=....
<snip>
2. We use cpuset/cgroup to classify tasks and assign them into
different cgroups. For example "backgrond" group which binds tasks
only to little CPUs or "foreground" which makes use of all CPUs.
Tasks can be migrated between groups by a request if an acceleration
is needed.
See below an example how "surfaceflinger" task gets migrated.
Initially it is located in the "system-background" cgroup which
allows to run only on little cores. In order to speed it up it
can be temporary moved into "foreground" cgroup which allows
to use big/all CPUs:
cgroup_attach_task():
-> cgroup_migrate_execute()
-> cpuset_can_attach()
-> percpu_down_write()
-> rcu_sync_enter()
-> synchronize_rcu()
-> now move tasks to the new cgroup.
-> cgroup_migrate_finish()
<snip>
rcuop/1-29 [000] ..... 7030.528570: rcu_invoke_callback: rcu_preempt rhp=00000000461605e0 func=wakeme_after_rcu.cfi_jt
PERFD-SERVER-1855 [000] d..1. 7030.530293: cgroup_attach_task: dst_root=3 dst_id=22 dst_level=1 dst_path=/foreground pid=1900 comm=surfaceflinger
TimerDispatch-2768 [002] d..5. 7030.537542: sched_migrate_task: comm=surfaceflinger pid=1900 prio=98 orig_cpu=0 dest_cpu=4
<snip>
"Boosting a task" depends on synchronize_rcu() latency:
- first trace shows a completion of synchronize_rcu();
- second shows attaching a task to a new group;
- last shows a final step when migration occurs.
3. To address this drawback, maintain a separate track that consists
of synchronize_rcu() callers only. After completion of a grace period
users are deferred to a dedicated worker to process requests.
4. This patch reduces the latency of synchronize_rcu() approximately
by ~30-40% on synthetic tests. The real test case, camera launch time,
shows(time is in milliseconds):
1-run 542 vs 489 improvement 9%
2-run 540 vs 466 improvement 13%
3-run 518 vs 468 improvement 9%
4-run 531 vs 457 improvement 13%
5-run 548 vs 475 improvement 13%
6-run 509 vs 484 improvement 4%
Synthetic test(no "noise" from other callbacks):
Hardware: x86_64 64 CPUs, 64GB of memory
Linux-6.6
- 10K tasks(simultaneous);
- each task does(1000 loops)
synchronize_rcu();
kfree(p);
default: CONFIG_RCU_NOCB_CPU: takes 54 seconds to complete all users;
patch: CONFIG_RCU_NOCB_CPU: takes 35 seconds to complete all users.
Running 60K gives approximately same results on my setup. Please note
it is without any interaction with another type of callbacks, otherwise
it will impact a lot a default case.
5. By default it is disabled. To enable this perform one of the
below sequence:
echo 1 > /sys/module/rcutree/parameters/rcu_normal_wake_from_gp
or pass a boot parameter "rcutree.rcu_normal_wake_from_gp=1"
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Co-developed-by: Neeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com>
Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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The rcuc-starvation output from print_cpu_stall_info() might overflow the
buffer if there is a huge difference in jiffies difference. The situation
might seem improbable, but computers sometimes get very confused about
time, which can result in full-sized integers, and, in this case,
buffer overflow.
Also, the unsigned jiffies difference is printed using %ld, which is
normally for signed integers. This is intentional for debugging purposes,
but it is not obvious from the code.
This commit therefore changes sprintf() to snprintf() and adds a
clarifying comment about intention of %ld format.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 245a62982502 ("rcu: Dump rcuc kthread status for CPUs not reporting quiescent state")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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When using "guard(rcu)();" sparse will complain, because even
though it now understands the cleanup attribute, it doesn't
evaluate the calls from it at function exit, and thus doesn't
count the context correctly.
Given that there's a conditional in the resulting code:
static inline void class_rcu_destructor(class_rcu_t *_T)
{
if (_T->lock) {
rcu_read_unlock();
}
}
it seems that even trying to teach sparse to evalulate the
cleanup attribute function it'd still be difficult to really
make it understand the full context here.
Suppress the sparse warning by just releasing the context in
the acquisition part of the function, after all we know it's
safe with the guard, that's the whole point of it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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There is a possibility of buffer overflow in
show_rcu_tasks_trace_gp_kthread() if counters, passed
to sprintf() are huge. Counter numbers, needed for this
are unrealistically high, but buffer overflow is still
possible.
Use snprintf() with buffer size instead of sprintf().
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: edf3775f0ad6 ("rcu-tasks: Add count for idle tasks on offline CPUs")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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The synchronize_srcu() has been removed by commit("rcu-tasks: Eliminate
deadlocks involving do_exit() and RCU tasks") in rcu_tasks_postscan.
This commit therefore fixes the tasks_rcu_exit_srcu_stall_timer comment.
Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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Because the Tasks RCU ->rtp_exit_list is initialized at rcu_init()
time while there is only one CPU running with interrupts disabled, it
is not possible for an exiting task to encounter an uninitialized list.
This commit therefore replaces the conditional initialization with
a WARN_ON_ONCE().
Reported-by: Frederic Weisbecker <frederic@kernel.org>
Closes: https://lore.kernel.org/all/ZdiNXmO3wRvmzPsr@lothringen/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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This is part of a larger series cleaning up the semantics of
should_be_locked and adding assertions around it; if we don't need an
iterator/path anymore, it clearly doesn't need to be locked.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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In __bch2_read_super(), if kstrdup() fails, it needs to release memory
in sb->holder, fix to call bch2_free_super() in the error path.
Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kselftest fixes from Shuah Khan:
"A fix to kselftest harness to prevent infinite loop triggered in an
assert in FIXTURE_TEARDOWN and a fix to a problem seen in being able
to stop subsystem-enable tests when sched events are being traced"
* tag 'linux_kselftest-fixes-6.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests/harness: Prevent infinite loop due to Assert in FIXTURE_TEARDOWN
selftests/ftrace: Limit length in subsystem-enable tests
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Currently normal HugeTLB fault ends up crashing the kernel, as p4dp derived
from p4d_offset() is an invalid address when PGTABLE_LEVEL = 5. A p4d level
entry needs to be allocated when not available while walking the page table
during HugeTLB faults. Let's call p4d_alloc() to allocate such entries when
required instead of current p4d_offset().
Unable to handle kernel paging request at virtual address ffffffff80000000
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
Data abort info:
ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
swapper pgtable: 4k pages, 52-bit VAs, pgdp=0000000081da9000
[ffffffff80000000] pgd=1000000082cec003, p4d=0000000082c32003, pud=0000000000000000
Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 108 Comm: high_addr_hugep Not tainted 6.9.0-rc4 #48
Hardware name: Foundation-v8A (DT)
pstate: 01402005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : huge_pte_alloc+0xd4/0x334
lr : hugetlb_fault+0x1b8/0xc68
sp : ffff8000833bbc20
x29: ffff8000833bbc20 x28: fff000080080cb58 x27: ffff800082a7cc58
x26: 0000000000000000 x25: fff0000800378e40 x24: fff00008008d6c60
x23: 00000000de9dbf07 x22: fff0000800378e40 x21: 0004000000000000
x20: 0004000000000000 x19: ffffffff80000000 x18: 1ffe00010011d7a1
x17: 0000000000000001 x16: ffffffffffffffff x15: 0000000000000001
x14: 0000000000000000 x13: ffff8000816120d0 x12: ffffffffffffffff
x11: 0000000000000000 x10: fff00008008ebd0c x9 : 0004000000000000
x8 : 0000000000001255 x7 : fff00008003e2000 x6 : 00000000061d54b0
x5 : 0000000000001000 x4 : ffffffff80000000 x3 : 0000000000200000
x2 : 0000000000000004 x1 : 0000000080000000 x0 : 0000000000000000
Call trace:
huge_pte_alloc+0xd4/0x334
hugetlb_fault+0x1b8/0xc68
handle_mm_fault+0x260/0x29c
do_page_fault+0xfc/0x47c
do_translation_fault+0x68/0x74
do_mem_abort+0x44/0x94
el0_da+0x2c/0x9c
el0t_64_sync_handler+0x70/0xc4
el0t_64_sync+0x190/0x194
Code: aa000084 cb010084 b24c2c84 8b130c93 (f9400260)
---[ end trace 0000000000000000 ]---
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Fixes: a6bbf5d4d9d1 ("arm64: mm: Add definitions to support 5 levels of paging")
Reported-by: Dev Jain <dev.jain@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/r/20240415094003.1812018-1-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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The #if condition controlling the rcu_preempt_sleep_check() definition
has a redundant check for CONFIG_PREEMPT_RCU, which is already checked
for by an enclosing #ifndef. This commit therefore removes this redundant
condition from the inner #if.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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Tasks Trace RCU needs a single-byte cmpxchg(), but no such thing exists.
Therefore, rcu_trc_cmpxchg_need_qs() emulates one using field substitution
and a four-byte cmpxchg(), such that the other three bytes are always
atomically updated to their old values. This works, but results in
false-positive KCSAN failures because as far as KCSAN knows, this
cmpxchg() operation is updating all four bytes.
This commit therefore encloses the cmpxchg() in a data_race() and adds
a single-byte instrument_atomic_read_write(), thus telling KCSAN exactly
what is going on so as to avoid the false positives.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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The FF-A uses the notification pending interrupt to inform the receiver
that it has a pending notification. This is a virtual interrupt and is
used by the following type of receivers:
1. A guest/VM running under a hypervisor.
2. An S-EL1 SP running under a S-EL2 SPMC.
The rules that govern the properties of the NPI are the same as the
rules for the SRI with couple of exceptions. Both SRI and NPI can be
supported simultaneously.
The handling of NPI is also same as the handling of notification for the
self/primary VM with ID 0 except the absence of global notification.
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Link: https://lore.kernel.org/r/20240411-ffa_npi_support-v2-3-927a670254e6@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
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In preparation to support handling of Notification Pending Interrupt(NPI)
in addition to the existing support for Schedule Receiver Interrupt(SRI),
refactor the code around SRI handling so that NPI support can reuse some
of it. This change shouldn't have any functionality impact. It neither
adds the support for NPIs nor changes any SRI support.
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Link: https://lore.kernel.org/r/20240411-ffa_npi_support-v2-2-927a670254e6@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
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When the FF-A driver is running inside a guest VM under an hypervisor,
the driver/guest VM doesn't have the permission/capability to request
the creation of notification bitmaps. For a VM, the hypervisor reserves
memory for its VM and hypervisor framework notification bitmaps and the
SPMC reserves memory for its SP and SPMC framework notification bitmaps
before the hypervisor initializes it.
The hypervisor does not initialize a VM if memory cannot be reserved
for all its notification bitmaps. So the creation of all the necessary
bitmaps are already done when the driver initialises and hence it can be
skipped. We rely on FFA_FEATURES(FFA_NOTIFICATION_BITMAP_CREATE) to fail
when running in the guest to handle this in the driver.
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Link: https://lore.kernel.org/r/20240411-ffa_npi_support-v2-1-927a670254e6@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
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The table of primary plane formats wasn't sorted at all, leading to
applications picking our least desirable formats by defaults.
Sort the primary plane formats according to our order of preference.
Nice side-effect of this change is that it makes IGT's kms_atomic
plane-invalid-params pass because the test picks the first format
which for vmwgfx was DRM_FORMAT_XRGB1555 and uses fb's with odd sizes
which make Pixman, which IGT depends on assert due to the fact that our
16bpp formats aren't 32 bit aligned like Pixman requires all formats
to be.
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Fixes: 36cc79bc9077 ("drm/vmwgfx: Add universal plane support")
Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.12+
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240412025511.78553-6-zack.rusin@broadcom.com
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The conditional was supposed to prevent enabling of a crtc state
without a set primary plane. Accidently it also prevented disabling
crtc state with a set primary plane. Neither is correct.
Fix the conditional and just driver-warn when a crtc state has been
enabled without a primary plane which will help debug broken userspace.
Fixes IGT's kms_atomic_interruptible and kms_atomic_transition tests.
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Fixes: 06ec41909e31 ("drm/vmwgfx: Add and connect CRTC helper functions")
Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.12+
Reviewed-by: Ian Forbes <ian.forbes@broadcom.com>
Reviewed-by: Martin Krastev <martin.krastev@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240412025511.78553-5-zack.rusin@broadcom.com
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vmwgfx never supported prime import of external buffers. Furthermore the
driver exposes two different objects to userspace: vmw_surface's and
gem buffers but prime import/export only worked with vmw_surfaces.
Because gem buffers are used through the dumb_buffer interface this meant
that the driver created buffers couldn't have been prime exported or
imported.
Fix prime import/export. Makes IGT's kms_prime pass.
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Fixes: 8afa13a0583f ("drm/vmwgfx: Implement DRIVER_GEM")
Cc: <stable@vger.kernel.org> # v6.6+
Reviewed-by: Martin Krastev <martin.krastev@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240412025511.78553-4-zack.rusin@broadcom.com
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Rearrange the instructions so that readers facing a regression within a
stable or longterm series first test its latest release before testing
mainline. This is less scary for some people. It also reduces the chance
that something goes sideways for readers that compile their first
kernel, as mainline can cause slightly more trouble.
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/efd3cb9c68db450091021326bf9c334553df0ec2.1712647788.git.linux@leemhuis.info
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Describe how to build kernels on another system (with and without
cross-compiling), as building locally can be quite painfully on some
slow systems. This is done in an add-on section, as it would make the
step-by-step guide to complicated if this special case would be
described there.
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/288160cb4769e46a3280250ca71da0abc4aa002d.1712647788.git.linux@leemhuis.info
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Rename 'Supplementary tasks' to 'Complementary tasks' while introducing
a section 'Optional tasks: test reverts, patches, or later versions':
the latter is something readers occasionally will have to do after
reporting a bug and thus is best covered here.
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/dacf26a4c48e9e8f04ecbc77e0a74c9b2a6a1103.1712647788.git.linux@leemhuis.info
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Various small improvements and fixes:
* Separate ref links from their target with a space for better
readability.
* Add a proper heading for the note at the end of the step-by-step
guide.
* Use proper 3rd and 4th level headlines in the reference section and
add short intros for the 2nd level headlines that lacked one.
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/f59f0f235a2192ed93899a7338153e4cb71075f0.1712647788.git.linux@leemhuis.info
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Add and fetch all required stable branches ahead of time. This fixes a
bug, as readers that wanted to bisect a regression within a stable or
longterm series otherwise did not have them available at the right time.
This way also matches the flow somewhat better and avoids some "if you
haven't already added it" phrases that otherwise become necessary in
future changes.
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/57dcf312959476abe6151bf3d35eb79e3e9a83d1.1712647788.git.linux@leemhuis.info
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Various small improvements and fixes:
* Use the more modern 'git switch' instead of 'git checkout', which
makes it more obvious what's happening (among others due to the
--discard-changes parameter that is more clear than --force).
* Provide a hint how a mainline version number and one from a stable
series look like.
* When trying to validate the bisection result with a revert, add a
special tag to facilitate the identification.
* Sync version numbers used in various examples for consistency: stick
to 6.0.13, 6.0.15, and 6.1.5.
* Fix a few typos and oddities.
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/85029aa004447b0eeb5043fb014630f2acafacec.1712647788.git.linux@leemhuis.info
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Allow the power-domains property to the PWM_DISP block as on some SoCs
this does need at most one power domain.
Fixes: b09b179bac0a ("dt-bindings: pwm: Convert pwm-mtk-disp.txt to mediatek,pwm-disp.yaml format")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240404081808.92199-1-angelogioacchino.delregno@collabora.com
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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With 16 channel pwm support, we're registering two instances of pwm_chip
with 8 channels each. We need to update PM functions to use both instances
of pwm_chip during power state transitions.
Introduce struct dwc_pwm_drvdata and use it as driver_data, which will
maintain both instances of pwm_chip along with dwc_pwm_info and allow us
to use them inside suspend/resume handles.
Fixes: ebf2c89eb95e ("pwm: dwc: Add 16 channel support for Intel Elkhart Lake")
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240415074051.14681-1-raag.jadav@intel.com
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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We only pool write combined and uncached allocations because they
require extra overhead on allocation and release.
If we also pool cached NUMA it not only means some extra unnecessary
overhead, but also that under memory pressure it can happen that
pages from the wrong NUMA node enters the pool and are re-used
over and over again.
This can lead to performance reduction after running into memory
pressure.
v2: restructure and cleanup the code a bit from the internal hack to
test this.
Signed-off-by: Christian König <christian.koenig@amd.com>
Fixes: 4482d3c94d7f ("drm/ttm: add NUMA node id to the pool")
CC: stable@vger.kernel.org
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240415134821.1919-1-christian.koenig@amd.com
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Now the __GFP_COMP is set only if the higher-order is not 0. However,
__GFP_COMP flag can be set unconditionally because compound page can
not be created in the order-0 case. And this can also simplify the code
a bit (no need to check the order is 0 or not).
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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Currently, there are rcu_data structure fields named ->rcu_onl_gp_seq
and ->rcu_ofl_gp_seq that track the rcu_state.gp_flags field at the
time of the corresponding CPU's last online or offline operation,
respectively. However, this information is not particularly useful.
It would be better to instead track the grace period state kept
in rcu_state.gp_state. This would also be consistent with the
initialization in rcu_boot_init_percpu_data(), which is to RCU_GP_CLEANED
(an rcu_state.gp_state value), and also with the diagnostics in
rcu_implicit_dynticks_qs(), whose format is consistent with an integer,
not a bitmask.
This commit therefore makes this change and changes the names to
->rcu_onl_gp_flags and ->rcu_ofl_gp_flags, respectively.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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The rcu_state.n_online_cpus value is only ever updated by CPU-hotplug
operations, which are serialized. However, this value is read locklessly.
This commit therefore marks those reads. While in the area, it also
adds ASSERT_EXCLUSIVE_WRITER() calls just in case parallel CPU hotplug
becomes a thing.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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The rcu_sync structure's ->gp_count field is updated under the protection
of ->rss_lock, but read locklessly, and KCSAN noted the data race.
This commit therefore uses WRITE_ONCE() to do this update to clearly
document its racy nature.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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This commit adds READ_ONCE() to a lockless diagnostic read from
rcu_state.gp_flags to avoid giving the compiler any chance whatsoever
of confusing the diagnostic state printed.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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The of_match shall correspond to the name of the regulator subnode,
or the deprecated `regulator-compatible` property must be used:
failing to do so, the regulator won't probe (and the driver will
as well not probe).
Since the devicetree binding for this driver is actually correct
and wants DTs to use the "usb-otg-vbus-regulator" subnode name,
fix this driver by aligning the `of_match` string to what the DT
binding wants.
Fixes: 0402e8ebb8b8 ("power: supply: mt6360_charger: add MT6360 charger support")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20240410084405.1389378-1-angelogioacchino.delregno@collabora.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Although it is functionally OK to do READ_ONCE() of a variable that
cannot change, it is confusing and at best an accident waiting to happen.
This commit therefore removes a number of READ_ONCE(rcu_state.gp_flags)
instances from kernel/rcu/tree.c that are not needed due to updates
to this field being excluded by virtue of holding the root rcu_node
structure's ->lock.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Closes: https://lore.kernel.org/lkml/4857c5ef-bd8f-4670-87ac-0600a1699d05@paulmck-laptop/T/#mccb23c2a4902da4d3c750165329f8de056903c58
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Closes: https://lore.kernel.org/lkml/4857c5ef-bd8f-4670-87ac-0600a1699d05@paulmck-laptop/T/#md1b5c026584f9c3c7b0fbc9240dd7de584597b73
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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MTD OTP logic is very fragile on parsing NVMEM cell and can be
problematic with some specific kind of devices.
The problem was discovered by e87161321a40 ("mtd: rawnand: macronix:
OTP access for MX30LFxG18AC") where OTP support was added to a NAND
device. With the case of NAND devices, it does require a node where ECC
info are declared and all the fixed partitions, and this cause the OTP
codepath to parse this node as OTP NVMEM cells, making probe fail and
the NAND device registration fail.
MTD OTP parsing should have been limited to always using compatible to
prevent this error by using node with compatible "otp-user" or
"otp-factory".
NVMEM across the years had various iteration on how cells could be
declared in DT, in some old implementation, no_of_node should have been
enabled but now add_legacy_fixed_of_cells should be used to disable
NVMEM to parse child node as NVMEM cell.
To fix this and limit any regression with other MTD that makes use of
declaring OTP as direct child of the dev node, disable
add_legacy_fixed_of_cells if we detect the MTD type is Nand.
With the following logic, the OTP NVMEM entry is correctly created with
no cells and the MTD Nand is correctly probed and partitions are
correctly exposed.
Fixes: 4b361cfa8624 ("mtd: core: add OTP nvmem provider support")
Cc: <stable@vger.kernel.org> # v6.7+
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240412105030.1598-1-ansuelsmth@gmail.com
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Upon reviewing the flower control flags handling in
this driver, I notice that the key wasn't being used,
only the mask.
Ie. `tc flower ... ip_flags nofrag` was hardware
offloaded as `... ip_flags frag`.
Only compile tested, no access to HW.
Fixes: c672e3727989 ("octeontx2-pf: Add support to filter packet based on IP fragment")
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Because Tiny RCU is used only in kernels built with either
CONFIG_PREEMPT_NONE=y or CONFIG_PREEMPT_VOLUNTARY=y, there has not been
any need for TINY RCU to explicitly disable preemption. However, the
prospect of lazy preemption changes that, and preemption means that
the non-atomic increment in synchronize_rcu() can be preempted, with
the possibility that one of the increments is lost. This could cause
failures for users of the APIs that poll RCU grace periods.
This commit therefore adds the needed preempt_disable() and
preempt_enable() call to Tiny RCU.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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The TINY_RCU rcu_process_callbacks() function is only ever invoked from
a softirq handler, which means that BH is already disabled. This commit
therefore removes the redundant local_bh_disable() and local_bh_ennable()
from this function.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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Currently, if a Kconfig option depends on TASKS_RCU, it conditionally does
"select TASKS_RCU if PREEMPTION". This works, but requires any change in
this enablement logic to be replicated across all such "select" clauses.
This commit therefore creates a new NEED_TASKS_RCU Kconfig option so
that the default value of TASKS_RCU can depend on a combination of this
new option and any needed enablement logic, so that this logic is in
one place.
While in the area, also anticipate a likely future change by adding
PREEMPT_AUTO to that logic.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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Because Tiny SRCU is used only in kernels built with either
CONFIG_PREEMPT_NONE=y or CONFIG_PREEMPT_VOLUNTARY=y, there has not
been any need for TINY SRCU to explicitly disable preemption. However,
the prospect of lazy preemption changes that, and the lazy-preemption
patches do result in rcutorture runs finding both too-short grace periods
and grace-period hangs for Tiny SRCU.
This commit therefore adds the needed preempt_disable() and
preempt_enable() calls to Tiny SRCU.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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Right now, TINY_RCU depends on (!PREEMPTION && !SMP), which has served the
kernel well for many years due to the fact that PREEMPT_RCU is normally
a synonym for PREEMPTION. But with the advent of lazy preemption,
it will be possible to have non-preemptible RCU in a preemptible kernel,
so that kernels could be built with PREEMPT_RCU=n and PREEMPTION=y.
This commit therefore makes TINY_RCU depend on (!PREEMPT_RCU && !SMP),
thus allowing for a non-preemptible RCU in preemptible kernels.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
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With Ankur's lazy-/auto-preemption patches applied and with a
lazy-preemptible kernel in combination with a non-preemptible RCU,
lockdep sometimes complains about context switches within RCU read-side
critical sections. This is a false positive due to rcu_read_unlock()
updating lockdep state too late:
__release(RCU);
__rcu_read_unlock();
// Context switch here results in lockdep false positive!!!
rcu_lock_release(&rcu_lock_map); /* Keep acq info for rls diags. */
Although this complaint could also happen with preemptible RCU
in a preemptible kernel, the odds of that happening aer quite low.
In constrast, with non-preemptible RCU, a long critical section has a
high probability of performing a context switch from the preempt_enable()
in __rcu_read_unlock().
The fix is straightforward, just move the rcu_lock_release()
within rcu_read_unlock() to obtain the reverse order from that of
rcu_read_lock():
rcu_lock_release(&rcu_lock_map); /* Keep acq info for rls diags. */
__release(RCU);
__rcu_read_unlock();
This commit makes this change.
Co-developed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Co-developed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
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Commit under Fixes optimized the number of recv() calls
needed during RTM_GETROUTE dumps, but we got multiple
reports of applications hanging on recv() calls.
Applications expect that a route dump will be terminated
with a recv() reading an individual NLM_DONE message.
Coalescing NLM_DONE is perfectly legal in netlink,
but even tho reporters fixed the code in respective
projects, chances are it will take time for those
applications to get updated. So revert to old behavior
(for now)?
Old kernel (5.19):
$ ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
--dump getroute --json '{"rtm-family": 2}'
Recv: read 692 bytes, 11 messages
nl_len = 68 (52) nl_flags = 0x22 nl_type = 24
...
nl_len = 60 (44) nl_flags = 0x22 nl_type = 24
Recv: read 20 bytes, 1 messages
nl_len = 20 (4) nl_flags = 0x2 nl_type = 3
Before (6.9-rc2):
$ ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
--dump getroute --json '{"rtm-family": 2}'
Recv: read 712 bytes, 12 messages
nl_len = 68 (52) nl_flags = 0x22 nl_type = 24
...
nl_len = 60 (44) nl_flags = 0x22 nl_type = 24
nl_len = 20 (4) nl_flags = 0x2 nl_type = 3
After:
$ ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
--dump getroute --json '{"rtm-family": 2}'
Recv: read 692 bytes, 11 messages
nl_len = 68 (52) nl_flags = 0x22 nl_type = 24
...
nl_len = 60 (44) nl_flags = 0x22 nl_type = 24
Recv: read 20 bytes, 1 messages
nl_len = 20 (4) nl_flags = 0x2 nl_type = 3
Reported-by: Stefano Brivio <sbrivio@redhat.com>
Link: https://lore.kernel.org/all/20240315124808.033ff58d@elisabeth
Reported-by: Ilya Maximets <i.maximets@ovn.org>
Link: https://lore.kernel.org/all/02b50aae-f0e9-47a4-8365-a977a85975d3@ovn.org
Fixes: 4ce5dc9316de ("inet: switch inet_dump_fib() to RCU protection")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This commit adds kernel-doc style comments with complete parameter
descriptions for the function cuse_process_init_reply.
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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When Output Resource (dcb->or) value is assigned in
fabricate_dcb_output(), there may be out of bounds access to
dac_users array in case dcb->or is zero because ffs(dcb->or) is
used as index there.
The 'or' argument of fabricate_dcb_output() must be interpreted as a
number of bit to set, not value.
Utilize macros from 'enum nouveau_or' in calls instead of hardcoding.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 2e5702aff395 ("drm/nouveau: fabricate DCB encoder table for iMac G4")
Fixes: 670820c0e6a9 ("drm/nouveau: Workaround incorrect DCB entry on a GeForce3 Ti 200.")
Signed-off-by: Mikhail Kobuk <m.kobuk@ispras.ru>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240411110854.16701-1-m.kobuk@ispras.ru
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Running a lot of VK CTS in parallel against nouveau, once every
few hours you might see something like this crash.
BUG: kernel NULL pointer dereference, address: 0000000000000008
PGD 8000000114e6e067 P4D 8000000114e6e067 PUD 109046067 PMD 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 7 PID: 53891 Comm: deqp-vk Not tainted 6.8.0-rc6+ #27
Hardware name: Gigabyte Technology Co., Ltd. Z390 I AORUS PRO WIFI/Z390 I AORUS PRO WIFI-CF, BIOS F8 11/05/2021
RIP: 0010:gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]
Code: c7 48 01 c8 49 89 45 58 85 d2 0f 84 95 00 00 00 41 0f b7 46 12 49 8b 7e 08 89 da 42 8d 2c f8 48 8b 47 08 41 83 c7 01 48 89 ee <48> 8b 40 08 ff d0 0f 1f 00 49 8b 7e 08 48 89 d9 48 8d 75 04 48 c1
RSP: 0000:ffffac20c5857838 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00000000004d8001 RCX: 0000000000000001
RDX: 00000000004d8001 RSI: 00000000000006d8 RDI: ffffa07afe332180
RBP: 00000000000006d8 R08: ffffac20c5857ad0 R09: 0000000000ffff10
R10: 0000000000000001 R11: ffffa07af27e2de0 R12: 000000000000001c
R13: ffffac20c5857ad0 R14: ffffa07a96fe9040 R15: 000000000000001c
FS: 00007fe395eed7c0(0000) GS:ffffa07e2c980000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000011febe001 CR4: 00000000003706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
...
? gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]
? gp100_vmm_pgt_mem+0x37/0x180 [nouveau]
nvkm_vmm_iter+0x351/0xa20 [nouveau]
? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
? __lock_acquire+0x3ed/0x2170
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
nvkm_vmm_ptes_get_map+0xc2/0x100 [nouveau]
? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
nvkm_vmm_map_locked+0x224/0x3a0 [nouveau]
Adding any sort of useful debug usually makes it go away, so I hand
wrote the function in a line, and debugged the asm.
Every so often pt->memory->ptrs is NULL. This ptrs ptr is set in
the nv50_instobj_acquire called from nvkm_kmap.
If Thread A and Thread B both get to nv50_instobj_acquire around
the same time, and Thread A hits the refcount_set line, and in
lockstep thread B succeeds at refcount_inc_not_zero, there is a
chance the ptrs value won't have been stored since refcount_set
is unordered. Force a memory barrier here, I picked smp_mb, since
we want it on all CPUs and it's write followed by a read.
v2: use paired smp_rmb/smp_wmb.
Cc: <stable@vger.kernel.org>
Fixes: be55287aa5ba ("drm/nouveau/imem/nv50: embed nvkm_instobj directly into nv04_instobj")
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240411011510.2546857-1-airlied@gmail.com
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U-Boot uses "ethernet0", not "eth0".
While at it, fix nearby whitespace errors (TAB instead of space before
equal sign).
Fixes: 93be50c7ff8e8087 ("arm64: dts: renesas: Add R-Car S4 Starter Kit support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/2f62c29e4222387a95ebadc65ba90a0cdea9b78c.1712647914.git.geert+renesas@glider.be
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