summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/smp.c
AgeCommit message (Collapse)Author
2024-11-02powerpc: Split systemcfg struct definitions out from vdsoThomas Weißschuh
The systemcfg data has nothing to do anymore with the vdso. Split it into a dedicated header file. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-27-b64f0842d512@linutronix.de
2024-11-02powerpc: Split systemcfg data out of vdso data pageThomas Weißschuh
The systemcfg data only has minimal overlap with the vdso data. Splitting the two avoids mapping the implementation-defined vdso data into /proc/ppc64/systemcfg. It is also a preparation for the standardization of vdso data storage. The only field actually used by both systemcfg and vdso is tb_ticks_per_sec and it is only changed once during time_init(). Initialize it in both structures there. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-26-b64f0842d512@linutronix.de
2024-09-08smp: Mark smp_prepare_boot_cpu() __initBibo Mao
smp_prepare_boot_cpu() is only called during boot, hence mark it as __init. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Huacai Chen <chenhuacai@loongson.cn> Link: https://lore.kernel.org/all/20240907082720.452148-1-maobibo@loongson.cn
2024-05-08powerpc: Fix typosBjorn Helgaas
Fix typos, most reported by "codespell arch/powerpc". Only touches comments, no code changes. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240103231605.1801364-8-helgaas@kernel.org
2024-03-17powerpc/kdump: Split KEXEC_CORE and CRASH_DUMP dependencyHari Bathini
Remove CONFIG_CRASH_DUMP dependency on CONFIG_KEXEC. CONFIG_KEXEC_CORE was used at places where CONFIG_CRASH_DUMP or CONFIG_CRASH_RESERVE was appropriate. Replace with appropriate #ifdefs to support CONFIG_KEXEC and !CONFIG_CRASH_DUMP configuration option. Also, make CONFIG_FA_DUMP dependent on CONFIG_CRASH_DUMP to avoid unmet dependencies for FA_DUMP with !CONFIG_KEXEC_CORE configuration option. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240226103010.589537-4-hbathini@linux.ibm.com
2024-02-28sched/topology: Rename SD_SHARE_PKG_RESOURCES to SD_SHARE_LLCAlex Shi
SD_SHARE_PKG_RESOURCES is a bit of a misnomer: its naming suggests that it's sharing all 'package resources' - while in reality it's specifically for sharing the LLC only. Rename it to SD_SHARE_LLC to reduce confusion. [ mingo: Rewrote the confusing changelog as well. ] Suggested-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Alex Shi <alexs@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Valentin Schneider <vschneid@redhat.com> Reviewed-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Reviewed-by: Barry Song <baohua@kernel.org> Link: https://lore.kernel.org/r/20240210113924.1130448-5-alexs@kernel.org
2023-12-15powerpc/smp: Dynamically build Powerpc topologySrikar Dronamraju
Currently there are four Powerpc specific sched topologies. These are all statically defined. However not all these topologies are used by all Powerpc systems. To avoid unnecessary degenerations by the scheduler, masks and flags are compared. However if the sched topologies are build dynamically then the code is simpler and there are greater chances of avoiding degenerations. Note: Even X86 builds its sched topologies dynamically and proposed changes are very similar to the way X86 is building its topologies. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231214180720.310852-6-srikar@linux.vnet.ibm.com
2023-12-15powerpc/smp: Avoid asym packing within thread_group of a coreSrikar Dronamraju
PowerVM Hypervisor will schedule at a core granularity. However each core can have more than one thread_groups. For better utilization in case of a shared processor, its preferable for the scheduler to pack to the lowest core. However there is no benefit of moving a thread between two thread groups of the same core. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231214180720.310852-5-srikar@linux.vnet.ibm.com
2023-12-15powerpc/smp: Add __ro_after_init attributeSrikar Dronamraju
There are some variables that are only updated at boot time. So add __ro_after_init attribute to such variables Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231214180720.310852-4-srikar@linux.vnet.ibm.com
2023-12-15powerpc/smp: Disable MC domain for shared processorSrikar Dronamraju
Like L2-cache info, coregroup information which is used to determine MC sched domains is only present on dedicated LPARs. i.e PowerVM doesn't export coregroup information for shared processor LPARs. Hence disable creating MC domains on shared LPAR Systems. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231214180720.310852-3-srikar@linux.vnet.ibm.com
2023-12-15powerpc/smp: Enable Asym packing for cores on shared processorSrikar Dronamraju
If there are shared processor LPARs, underlying Hypervisor can have more virtual cores to handle than actual physical cores. Starting with Power 9, a big core (aka SMT8 core) has 2 nearly independent thread groups. On a shared processors LPARs, it helps to pack threads to lesser number of cores so that the overall system performance and utilization improves. PowerVM schedules at a big core level. Hence packing to fewer cores helps. Since each thread-group is independent, running threads on both the thread-groups of a SMT8 core, should have a minimal adverse impact in non over provisioned scenarios. These changes in this patchset will not affect in the over provisioned scenario. If there are more threads than SMT domains, then asym_packing will not kick-in For example: Lets says there are two 8-core Shared LPARs that are actually sharing a 8 Core shared physical pool, each running 8 threads each. Then Consolidating 8 threads to 4 cores on each LPAR would help them to perform better. This is because each of the LPAR will get 100% time to run applications and there will no switching required by the Hypervisor. To achieve this, enable SD_ASYM_PACKING flag at CACHE, MC and DIE level when the system is running in shared processor mode and has big cores. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231214180720.310852-2-srikar@linux.vnet.ibm.com
2023-10-30Merge tag 'rcu-next-v6.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks Pull RCU updates from Frederic Weisbecker: - RCU torture, locktorture and generic torture infrastructure updates that include various fixes, cleanups and consolidations. Among the user visible things, ftrace dumps can now be found into their own file, and module parameters get better documented and reported on dumps. - Generic and misc fixes all over the place. Some highlights: * Hotplug handling has seen some light cleanups and comments * An RCU barrier can now be triggered through sysfs to serialize memory stress testing and avoid OOM * Object information is now dumped in case of invalid callback invocation * Also various SRCU issues, too hard to trigger to deserve urgent pull requests, have been fixed - RCU documentation updates - RCU reference scalability test minor fixes and doc improvements. - RCU tasks minor fixes - Stall detection updates. Introduce RCU CPU Stall notifiers that allows a subsystem to provide informations to help debugging. Also cure some false positive stalls. * tag 'rcu-next-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks: (56 commits) srcu: Only accelerate on enqueue time locktorture: Check the correct variable for allocation failure srcu: Fix callbacks acceleration mishandling rcu: Comment why callbacks migration can't wait for CPUHP_RCUTREE_PREP rcu: Standardize explicit CPU-hotplug calls rcu: Conditionally build CPU-hotplug teardown callbacks rcu: Remove references to rcu_migrate_callbacks() from diagrams rcu: Assume rcu_report_dead() is always called locally rcu: Assume IRQS disabled from rcu_report_dead() rcu: Use rcu_segcblist_segempty() instead of open coding it rcu: kmemleak: Ignore kmemleak false positives when RCU-freeing objects srcu: Fix srcu_struct node grpmask overflow on 64-bit systems torture: Convert parse-console.sh to mktemp rcutorture: Traverse possible cpu to set maxcpu in rcu_nocb_toggle() rcutorture: Replace schedule_timeout*() 1-jiffy waits with HZ/20 torture: Add kvm.sh --debug-info argument locktorture: Rename readers_bind/writers_bind to bind_readers/bind_writers doc: Catch-up update for locktorture module parameters locktorture: Add call_rcu_chains module parameter locktorture: Add new module parameters to lock_torture_print_module_parms() ...
2023-10-12sched/topology: Rename 'DIE' domain to 'PKG'Peter Zijlstra
While reworking the x86 topology code Thomas tripped over creating a 'DIE' domain for the package mask. :-) Since these names are CONFIG_SCHED_DEBUG=y only, rename them to make the name less ambiguous. [ Shrikanth Hegde: rename on s390 as well. ] [ Valentin Schneider: also rename it in the comments. ] [ mingo: port to recent kernels & find all remaining occurances. ] Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Valentin Schneider <vschneid@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20230712141056.GI3100107@hirez.programming.kicks-ass.net
2023-10-04rcu: Standardize explicit CPU-hotplug callsFrederic Weisbecker
rcu_report_dead() and rcutree_migrate_callbacks() have their headers in rcupdate.h while those are pure rcutree calls, like the other CPU-hotplug functions. Also rcu_cpu_starting() and rcu_report_dead() have different naming conventions while they mirror each other's effects. Fix the headers and propose a naming that relates both functions and aligns with the prefix of other rcutree CPU-hotplug functions. Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2023-08-14Merge branch 'topic/cpu-smt' into nextMichael Ellerman
Merge SMT changes we are sharing with the tip tree.
2023-08-02powerpc: Add HOTPLUG_SMT supportMichael Ellerman
Add support for HOTPLUG_SMT, which enables the generic sysfs SMT support files in /sys/devices/system/cpu/smt, as well as the "nosmt" boot parameter. Implement the recently added hooks to allow partial SMT states, allow any number of threads per core. Tie the config symbol to HOTPLUG_CPU, which enables it on the major platforms that support SMT. If there are other platforms that want the SMT support that can be tweaked in future. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> [ldufour: remove topology_smt_supported] [ldufour: remove topology_smt_threads_supported] [ldufour: select CONFIG_SMT_NUM_THREADS_DYNAMIC] [ldufour: update kernel-parameters.txt] Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Link: https://msgid.link/20230705145143.40545-10-ldufour@linux.ibm.com
2023-08-02powerpc: Account mm_cpumask and active_cpus in init_mmNicholas Piggin
init_mm mm_cpumask and context.active_cpus is not maintained at boot and hotplug. This seems to be harmless because init_mm does not have a userspace and so never gets user TLBs flushed, but it looks odd and it prevents some sanity checks being added. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230524060821.148015-2-npiggin@gmail.com
2023-06-30Merge tag 'powerpc-6.5-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Extend KCSAN support to 32-bit and BookE. Add some KCSAN annotations - Make ELFv2 ABI the default for 64-bit big-endian kernel builds, and use the -mprofile-kernel option (kernel specific ftrace ABI) for big endian ELFv2 kernels - Add initial Dynamic Execution Control Register (DEXCR) support, and allow the ROP protection instructions to be used on Power 10 - Various other small features and fixes Thanks to Aditya Gupta, Aneesh Kumar K.V, Benjamin Gray, Brian King, Christophe Leroy, Colin Ian King, Dmitry Torokhov, Gaurav Batra, Jean Delvare, Joel Stanley, Marco Elver, Masahiro Yamada, Nageswara R Sastry, Nathan Chancellor, Naveen N Rao, Nayna Jain, Nicholas Piggin, Paul Gortmaker, Randy Dunlap, Rob Herring, Rohan McLure, Russell Currey, Sachin Sant, Timothy Pearson, Tom Rix, and Uwe Kleine-König. * tag 'powerpc-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (76 commits) powerpc: remove checks for binutils older than 2.25 powerpc: Fail build if using recordmcount with binutils v2.37 powerpc/iommu: TCEs are incorrectly manipulated with DLPAR add/remove of memory powerpc/iommu: Only build sPAPR access functions on pSeries powerpc: powernv: Annotate data races in opal events powerpc: Mark writes registering ipi to host cpu through kvm and polling powerpc: Annotate accesses to ipi message flags powerpc: powernv: Fix KCSAN datarace warnings on idle_state contention powerpc: Mark [h]ssr_valid accesses in check_return_regs_valid powerpc: qspinlock: Enforce qnode writes prior to publishing to queue powerpc: qspinlock: Mark accesses to qnode lock checks powerpc/powernv/pci: Remove last IODA1 defines powerpc/powernv/pci: Remove MVE code powerpc/powernv/pci: Remove ioda1 support powerpc: 52xx: Make immr_id DT match tables static powerpc: mpc512x: Remove open coded "ranges" parsing powerpc: fsl_soc: Use of_range_to_resource() for "ranges" parsing powerpc: fsl: Use of_property_read_reg() to parse "reg" powerpc: fsl_rio: Use of_range_to_resource() for "ranges" parsing macintosh: Use of_property_read_reg() to parse "reg" ...
2023-06-27Merge tag 'objtool-core-2023-06-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molar: "Build footprint & performance improvements: - Reduce memory usage with CONFIG_DEBUG_INFO=y In the worst case of an allyesconfig+CONFIG_DEBUG_INFO=y kernel, DWARF creates almost 200 million relocations, ballooning objtool's peak heap usage to 53GB. These patches reduce that to 25GB. On a distro-type kernel with kernel IBT enabled, they reduce objtool's peak heap usage from 4.2GB to 2.8GB. These changes also improve the runtime significantly. Debuggability improvements: - Add the unwind_debug command-line option, for more extend unwinding debugging output - Limit unreachable warnings to once per function - Add verbose option for disassembling affected functions - Include backtrace in verbose mode - Detect missing __noreturn annotations - Ignore exc_double_fault() __noreturn warnings - Remove superfluous global_noreturns entries - Move noreturn function list to separate file - Add __kunit_abort() to noreturns Unwinder improvements: - Allow stack operations in UNWIND_HINT_UNDEFINED regions - drm/vmwgfx: Add unwind hints around RBP clobber Cleanups: - Move the x86 entry thunk restore code into thunk functions - x86/unwind/orc: Use swap() instead of open coding it - Remove unnecessary/unused variables Fixes for modern stack canary handling" * tag 'objtool-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits) x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y objtool: Skip reading DWARF section data objtool: Free insns when done objtool: Get rid of reloc->rel[a] objtool: Shrink elf hash nodes objtool: Shrink reloc->sym_reloc_entry objtool: Get rid of reloc->jump_table_start objtool: Get rid of reloc->addend objtool: Get rid of reloc->type objtool: Get rid of reloc->offset objtool: Get rid of reloc->idx objtool: Get rid of reloc->list objtool: Allocate relocs in advance for new rela sections objtool: Add for_each_reloc() objtool: Don't free memory in elf_close() objtool: Keep GElf_Rel[a] structs synced objtool: Add elf_create_section_pair() objtool: Add mark_sec_changed() objtool: Fix reloc_hash size objtool: Consolidate rel/rela handling ...
2023-06-21powerpc: Annotate accesses to ipi message flagsRohan McLure
IPI message flags are observed and consequently consumed in the smp_ipi_demux_relaxed function, which handles these message sources until it observes none more arriving. Mark the checked loop guard with READ_ONCE, to signal to KCSAN that the read is known to be volatile, and that non-determinism is expected. Mark write for message source in smp_muxed_ipi_set_message(). Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230510033117.1395895-8-rmclure@linux.ibm.com
2023-06-05locking/atomic: treewide: use raw_atomic*_<op>()Mark Rutland
Now that we have raw_atomic*_<op>() definitions, there's no need to use arch_atomic*_<op>() definitions outside of the low-level atomic definitions. Move treewide users of arch_atomic*_<op>() over to the equivalent raw_atomic*_<op>(). There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230605070124.3741859-19-mark.rutland@arm.com
2023-05-16start_kernel: Add __no_stack_protector function attributendesaulniers@google.com
Back during the discussion of commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try") we discussed the need for a function attribute to control the omission of stack protectors on a per-function basis; at the time Clang had support for no_stack_protector but GCC did not. This was fixed in gcc-11. Now that the function attribute is available, let's start using it. Callers of boot_init_stack_canary need to use this function attribute unless they're compiled with -fno-stack-protector, otherwise the canary stored in the stack slot of the caller will differ upon the call to boot_init_stack_canary. This will lead to a call to __stack_chk_fail() then panic. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94722 Link: https://lore.kernel.org/all/20200316130414.GC12561@hirez.programming.kicks-ass.net/ Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Miguel Ojeda <ojeda@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20230412-no_stackp-v2-1-116f9fe4bbe7@google.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: ndesaulniers@google.com <ndesaulniers@google.com>
2023-04-28Merge tag 'smp-core-2023-04-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP cross-CPU function-call updates from Ingo Molnar: - Remove diagnostics and adjust config for CSD lock diagnostics - Add a generic IPI-sending tracepoint, as currently there's no easy way to instrument IPI origins: it's arch dependent and for some major architectures it's not even consistently available. * tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: trace,smp: Trace all smp_function_call*() invocations trace: Add trace_ipi_send_cpu() sched, smp: Trace smp callback causing an IPI smp: reword smp call IPI comment treewide: Trace IPIs sent via smp_send_reschedule() irq_work: Trace self-IPIs sent via arch_irq_work_raise() smp: Trace IPIs sent via arch_send_call_function_ipi_mask() sched, smp: Trace IPIs sent via send_call_function_single_ipi() trace: Add trace_ipi_send_cpumask() kernel/smp: Make csdlock_debug= resettable locking/csd_lock: Remove per-CPU data indirection from CSD lock debugging locking/csd_lock: Remove added data from CSD lock debugging locking/csd_lock: Add Kconfig option for csd_debug default
2023-04-28Merge tag 'objtool-core-2023-04-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molnar: - Mark arch_cpu_idle_dead() __noreturn, make all architectures & drivers that did this inconsistently follow this new, common convention, and fix all the fallout that objtool can now detect statically - Fix/improve the ORC unwinder becoming unreliable due to UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED to resolve it - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code - Generate ORC data for __pfx code - Add more __noreturn annotations to various kernel startup/shutdown and panic functions - Misc improvements & fixes * tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/hyperv: Mark hv_ghcb_terminate() as noreturn scsi: message: fusion: Mark mpt_halt_firmware() __noreturn x86/cpu: Mark {hlt,resume}_play_dead() __noreturn btrfs: Mark btrfs_assertfail() __noreturn objtool: Include weak functions in global_noreturns check cpu: Mark nmi_panic_self_stop() __noreturn cpu: Mark panic_smp_self_stop() __noreturn arm64/cpu: Mark cpu_park_loop() and friends __noreturn x86/head: Mark *_start_kernel() __noreturn init: Mark start_kernel() __noreturn init: Mark [arch_call_]rest_init() __noreturn objtool: Generate ORC data for __pfx code x86/linkage: Fix padding for typed functions objtool: Separate prefix code from stack validation code objtool: Remove superfluous dead_end_function() check objtool: Add symbol iteration helpers objtool: Add WARN_INSN() scripts/objdump-func: Support multiple functions context_tracking: Fix KCSAN noinstr violation objtool: Add stackleak instrumentation to uaccess safe list ...
2023-03-28lazy tlb: introduce lazy tlb mm refcount helper functionsNicholas Piggin
Add explicit _lazy_tlb annotated functions for lazy tlb mm refcounting. This makes the lazy tlb mm references more obvious, and allows the refcounting scheme to be modified in later changes. There is no functional change with this patch. Link: https://lkml.kernel.org/r/20230203071837.1136453-3-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-24treewide: Trace IPIs sent via smp_send_reschedule()Valentin Schneider
To be able to trace invocations of smp_send_reschedule(), rename the arch-specific definitions of it to arch_smp_send_reschedule() and wrap it into an smp_send_reschedule() that contains a tracepoint. Changes to include the declaration of the tracepoint were driven by the following coccinelle script: @func_use@ @@ smp_send_reschedule(...); @include@ @@ #include <trace/events/ipi.h> @no_include depends on func_use && !include@ @@ #include <...> + + #include <trace/events/ipi.h> [csky bits] [riscv bits] Signed-off-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Guo Ren <guoren@kernel.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230307143558.294354-6-vschneid@redhat.com
2023-03-08sched/idle: Mark arch_cpu_idle_dead() __noreturnJosh Poimboeuf
Before commit 076cbf5d2163 ("x86/xen: don't let xen_pv_play_dead() return"), in Xen, when a previously offlined CPU was brought back online, it unexpectedly resumed execution where it left off in the middle of the idle loop. There were some hacks to make that work, but the behavior was surprising as do_idle() doesn't expect an offlined CPU to return from the dead (in arch_cpu_idle_dead()). Now that Xen has been fixed, and the arch-specific implementations of arch_cpu_idle_dead() also don't return, give it a __noreturn attribute. This will cause the compiler to complain if an arch-specific implementation might return. It also improves code generation for both caller and callee. Also fixes the following warning: vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction Reported-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/60d527353da8c99d4cf13b6473131d46719ed16d.1676358308.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2022-12-02powerpc: allow minimum sized kernel stack framesNicholas Piggin
This affects only 64-bit ELFv2 kernels, and reduces the minimum asm-created stack frame size from 112 to 32 byte on those kernels. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221127124942.1665522-16-npiggin@gmail.com
2022-09-28powerpc/smp: poll cpu_callin_map more aggressively in __cpu_up()Nathan Lynch
At boot time, it is not necessary to delay between polls of cpu_callin_map when waiting for a kicked CPU to come up. Remove the delay intervals, but preserve the overall deadline (five seconds). At run time, the first poll result is usually negative and we incur a sleeping wait. If we spin on the callin word for a short time first, we can reduce __cpu_up() from dozens of milliseconds to under 1ms in the common case on a P9 LPAR: $ ppc64_cpu --smt=off $ bpftrace -e 'kprobe:__cpu_up { @start[tid] = nsecs; } kretprobe:__cpu_up /@start[tid]/ { @us = hist((nsecs - @start[tid]) / 1000); delete(@start[tid]); }' -c 'ppc64_cpu --smt=on' Before: @us: [16K, 32K) 85 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [32K, 64K) 13 |@@@@@@@ | After: @us: [128, 256) 95 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [256, 512) 3 |@ | Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220926220250.157022-1-nathanl@linux.ibm.com
2022-09-26powerpc: Remove CONFIG_PPC_FSL_BOOK3EChristophe Leroy
CONFIG_PPC_FSL_BOOK3E is redundant with CONFIG_PPC_E500. Remove it. And rename five files accordingly. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Rename include guards to match new file names] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/795cb93b88c9a0279289712e674f39e3b108a1b4.1663606876.git.christophe.leroy@csgroup.eu
2022-08-07Merge tag 'mm-nonmm-stable-2022-08-06-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc updates from Andrew Morton: "Updates to various subsystems which I help look after. lib, ocfs2, fatfs, autofs, squashfs, procfs, etc. A relatively small amount of material this time" * tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits) scripts/gdb: ensure the absolute path is generated on initial source MAINTAINERS: kunit: add David Gow as a maintainer of KUnit mailmap: add linux.dev alias for Brendan Higgins mailmap: update Kirill's email profile: setup_profiling_timer() is moslty not implemented ocfs2: fix a typo in a comment ocfs2: use the bitmap API to simplify code ocfs2: remove some useless functions lib/mpi: fix typo 'the the' in comment proc: add some (hopefully) insightful comments bdi: remove enum wb_congested_state kernel/hung_task: fix address space of proc_dohung_task_timeout_secs lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t() squashfs: support reading fragments in readahead call squashfs: implement readahead squashfs: always build "file direct" version of page actor Revert "squashfs: provide backing_dev_info in order to disable read-ahead" fs/ocfs2: Fix spelling typo in comment ia64: old_rr4 added under CONFIG_HUGETLB_PAGE proc: fix test for "vsyscall=xonly" boot option ...
2022-07-29profile: setup_profiling_timer() is moslty not implementedBen Dooks
The setup_profiling_timer() is mostly un-implemented by many architectures. In many places it isn't guarded by CONFIG_PROFILE which is needed for it to be used. Make it a weak symbol in kernel/profile.c and remove the 'return -EINVAL' implementations from the kenrel. There are a couple of architectures which do return 0 from the setup_profiling_timer() function but they don't seem to do anything else with it. To keep the /proc compatibility for now, leave these for a future update or removal. On ARM, this fixes the following sparse warning: arch/arm/kernel/smp.c:793:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static? Link: https://lkml.kernel.org/r/20220721195509.418205-1-ben-linux@fluff.org Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-28powerpc/crash: save cpu register data in crash_smp_send_stop()Hari Bathini
During kdump, two set of NMI IPIs are sent to secondary CPUs, if 'crash_kexec_post_notifiers' option is set. The first set of NMI IPIs to stop the CPUs and the other set to collect register data. Instead, capture register data for secondary CPUs while stopping them itself. Also, fallback to smp_send_stop() in case the function gets called without kdump configured. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220630064942.192283-1-hbathini@linux.ibm.com
2022-05-22powerpc: Fix all occurences of "the the"Michael Ellerman
Rather than waiting for the bots to fix these one-by-one, fix all occurences of "the the" throughout arch/powerpc. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220518142629.513007-1-mpe@ellerman.id.au
2022-05-22powerpc/kasan: Don't instrument non-maskable or raw interruptsDaniel Axtens
Disable address sanitization for raw and non-maskable interrupt handlers, because they can run in real mode, where we cannot access the shadow memory. (Note that kasan_arch_is_ready() doesn't test for real mode, since it is a static branch for speed, and in any case not all the entry points to the generic KASAN code are protected by kasan_arch_is_ready guards.) The changes to interrupt_nmi_enter/exit_prepare() look larger than they actually are. The changes are equivalent to adding !IS_ENABLED(CONFIG_KASAN) to the conditions for calling nmi_enter() or nmi_exit() in real mode. That is, the code is equivalent to using the following condition for calling nmi_enter/exit: if (((!IS_ENABLED(CONFIG_PPC_BOOK3S_64) || !firmware_has_feature(FW_FEATURE_LPAR) || radix_enabled()) && !IS_ENABLED(CONFIG_KASAN) || (mfmsr() & MSR_DR)) That unwieldy condition has been split into several statements with comments, for easier reading. The nmi_ipi_lock functions that call atomic functions (i.e., nmi_ipi_lock_start(), nmi_ipi_lock() and nmi_ipi_unlock()), besides being marked noinstr, now call arch_atomic_* functions instead of atomic_* functions because with KASAN enabled, the atomic_* functions are wrappers which explicitly do address sanitization on their arguments. Since we are trying to avoid address sanitization, we have to use the lower-level arch_atomic_* versions. In hv_nmi_check_nonrecoverable(), the regs_set_unrecoverable() call has been open-coded so as to avoid having to either trust the inlining or mark regs_set_unrecoverable() as noinstr. [paulus@ozlabs.org: combined a few work-in-progress commits of Daniel's and wrote the commit message.] Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/YoTFGaKM8Pd46PIK@cleo
2022-05-08powerpc: Remove asm/prom.h from all files that don't need itChristophe Leroy
Several files include asm/prom.h for no reason. Clean it up. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Drop change to prom_parse.c as reported by lkp@intel.com] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7c9b8fda63dcf63e1b28f43e7ebdb95182cbc286.1646767214.git.christophe.leroy@csgroup.eu
2022-05-05powerpc: fix typos in commentsJulia Lawall
Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr
2022-03-08powerpc: Move C prototypes out of asm-prototypes.hChristophe Leroy
We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc: Introduce asm-prototypes.h"). It's purpose was for prototypes of C functions that are only called from asm, in order to fix sparse warnings about missing prototypes. A few months later Nick added a different use case in commit 4efca4ed05cb ("kbuild: modversions for EXPORT_SYMBOL() for asm") for C prototypes for exported asm functions. This is basically the inverse of our original usage. Since then we've added various prototypes to asm-prototypes.h for both reasons, meaning we now need to unstitch it all. Dispatch prototypes of C functions into relevant headers and keep only the prototypes for functions defined in assembly. For the time being, leave prom_init() there because moving it into asm/prom.h or asm/setup.h conflicts with drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o This will be fixed later by untaggling asm/pci.h and asm/prom.h or by renaming the function in shadowrom.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu
2022-03-08powerpc/smp: Declare current_set staticChristophe Leroy
current_set extern not needed anymore since commit eafd825ed710 ("powerpc/64: Simplify __secondary_start paca->kstack handling") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a55eb65c9d7319f0af3c31e3f6ba36522f10003d.1646413435.git.christophe.leroy@csgroup.eu
2021-12-23powerpc/kernel: Add __init attribute to eligible functionsNick Child
Some functions defined in `arch/powerpc/kernel` (and one in `arch/powerpc/ kexec`) are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by: Nick Child <nick.child@ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211216220035.605465-2-nick.child@ibm.com
2021-12-09powerpc/fadump: Fix inaccurate CPU state info in vmcore generated with panicHari Bathini
In panic path, fadump is triggered via a panic notifier function. Before calling panic notifier functions, smp_send_stop() gets called, which stops all CPUs except the panic'ing CPU. Commit 8389b37dffdc ("powerpc: stop_this_cpu: remove the cpu from the online map.") and again commit bab26238bbd4 ("powerpc: Offline CPU in stop_this_cpu()") started marking CPUs as offline while stopping them. So, if a kernel has either of the above commits, vmcore captured with fadump via panic path would not process register data for all CPUs except the panic'ing CPU. Sample output of crash-utility with such vmcore: # crash vmlinux vmcore ... KERNEL: vmlinux DUMPFILE: vmcore [PARTIAL DUMP] CPUS: 1 DATE: Wed Nov 10 09:56:34 EST 2021 UPTIME: 00:00:42 LOAD AVERAGE: 2.27, 0.69, 0.24 TASKS: 183 NODENAME: XXXXXXXXX RELEASE: 5.15.0+ VERSION: #974 SMP Wed Nov 10 04:18:19 CST 2021 MACHINE: ppc64le (2500 Mhz) MEMORY: 8 GB PANIC: "Kernel panic - not syncing: sysrq triggered crash" PID: 3394 COMMAND: "bash" TASK: c0000000150a5f80 [THREAD_INFO: c0000000150a5f80] CPU: 1 STATE: TASK_RUNNING (PANIC) crash> p -x __cpu_online_mask __cpu_online_mask = $1 = { bits = {0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0} } crash> crash> crash> p -x __cpu_active_mask __cpu_active_mask = $2 = { bits = {0xff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0} } crash> While this has been the case since fadump was introduced, the issue was not identified for two probable reasons: - In general, the bulk of the vmcores analyzed were from crash due to exception. - The above did change since commit 8341f2f222d7 ("sysrq: Use panic() to force a crash") started using panic() instead of deferencing NULL pointer to force a kernel crash. But then commit de6e5d38417e ("powerpc: smp_send_stop do not offline stopped CPUs") stopped marking CPUs as offline till kernel commit bab26238bbd4 ("powerpc: Offline CPU in stop_this_cpu()") reverted that change. To ensure post processing register data of all other CPUs happens as intended, let panic() function take the crash friendly path (read crash_smp_send_stop()) with the help of crash_kexec_post_notifiers option. Also, as register data for all CPUs is captured by f/w, skip IPI callbacks here for fadump, to avoid any complications in finding the right backtraces. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211207103719.91117-2-hbathini@linux.ibm.com
2021-12-09powerpc: handle kdump appropriately with crash_kexec_post_notifiers optionHari Bathini
Kdump can be triggered after panic_notifers since commit f06e5153f4ae2 ("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers") introduced crash_kexec_post_notifiers option. But using this option would mean smp_send_stop(), that marks all other CPUs as offline, gets called before kdump is triggered. As a result, kdump routines fail to save other CPUs' registers. To fix this, kdump friendly crash_smp_send_stop() function was introduced with kernel commit 0ee59413c967 ("x86/panic: replace smp_send_stop() with kdump friendly version in panic path"). Override this kdump friendly weak function to handle crash_kexec_post_notifiers option appropriately on powerpc. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> [Fixed signature of crash_stop_this_cpu() - reported by lkp@intel.com] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211207103719.91117-1-hbathini@linux.ibm.com
2021-11-29powerpc/smp: Move setup_profiling_timer() under CONFIG_PROFILINGMichael Ellerman
setup_profiling_timer() is only needed when CONFIG_PROFILING is enabled. Fixes the following W=1 warning when CONFIG_PROFILING=n: linux/arch/powerpc/kernel/smp.c:1638:5: error: no previous prototype for ‘setup_profiling_timer’ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211124093254.1054750-5-mpe@ellerman.id.au
2021-11-02Merge tag 'devicetree-for-5.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull devicetree updates from Rob Herring: - Convert /reserved-memory bindings to schemas - Convert a bunch of NFC bindings to schemas - Convert bindings to schema: Xilinx USB, Freescale DDR controller, Arm CCI-400, UBlox Neo-6M, 1-Wire GPIO, MSI controller, ASpeed LPC, OMAP and Inside-Secure HWRNG, register-bit-led, OV5640, Silead GSL1680, Elan ekth3000, Marvell bluetooth, TI wlcore, TI bluetooth, ESP ESP8089, tlm,trusted-foundations, Microchip cap11xx, Ralink SoCs and boards, and TI sysc - New binding schemas for: msi-ranges, Aspeed UART routing controller, palmbus, Xylon LogiCVC display controller, Mediatek's MT7621 SDRAM memory controller, and Apple M1 PCIe host - Run schema checks for %.dtb targets - Improve build time when using DT_SCHEMA_FILES - Improve error message when dtschema is not found - Various doc reference fixes in MAINTAINERS - Convert architectures to common CPU h/w ID parsing function of_get_cpu_hwid(). - Allow for empty NUMA node IDs which may be hotplugged - Cleanup of __fdt_scan_reserved_mem() - Constify device_node parameters - Update dtc to upstream v1.6.1-19-g0a3a9d3449c8. Adds new checks 'node_name_vs_property_name' and 'interrupt_map'. - Enable dtc 'unit_address_format' warning by default - Fix unittest EXPECT text for gpio hog errors * tag 'devicetree-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (97 commits) dt-bindings: net: ti,bluetooth: Document default max-speed dt-bindings: pci: rcar-pci-ep: Document r8a7795 dt-bindings: net: qcom,ipa: IPA does support up to two iommus of/fdt: Remove of_scan_flat_dt() usage for __fdt_scan_reserved_mem() of: unittest: document intentional interrupt-map provider build warning of: unittest: fix EXPECT text for gpio hog errors of/unittest: Disable new dtc node_name_vs_property_name and interrupt_map warnings scripts/dtc: Update to upstream version v1.6.1-19-g0a3a9d3449c8 dt-bindings: arm: firmware: tlm,trusted-foundations: Convert txt bindings to yaml dt-bindings: display: tilcd: Fix endpoint addressing in example dt-bindings: input: microchip,cap11xx: Convert txt bindings to yaml dt-bindings: ufs: exynos-ufs: add exynosautov9 compatible dt-bindings: ufs: exynos-ufs: add io-coherency property dt-bindings: mips: convert Ralink SoCs and boards to schema dt-bindings: display: xilinx: Fix example with psgtr dt-bindings: net: nfc: nxp,pn544: Convert txt bindings to yaml dt-bindings: Add a help message when dtschema tools are missing dt-bindings: bus: ti-sysc: Update to use yaml binding dt-bindings: sram: Allow numbers in sram region node name dt-bindings: display: Document the Xylon LogiCVC display controller ...
2021-11-01Merge tag 'cpu-to-thread_info-v5.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull thread_info update to move 'cpu' back from task_struct from Kees Cook: "Cross-architecture update to move task_struct::cpu back into thread_info on arm64, x86, s390, powerpc, and riscv. All Acked by arch maintainers. Quoting Ard Biesheuvel: 'Move task_struct::cpu back into thread_info Keeping CPU in task_struct is problematic for architectures that define raw_smp_processor_id() in terms of this field, as it requires linux/sched.h to be included, which causes a lot of pain in terms of circular dependencies (aka 'header soup') This series moves it back into thread_info (where it came from) for all architectures that enable THREAD_INFO_IN_TASK, addressing the header soup issue as well as some pointless differences in the implementations of task_cpu() and set_task_cpu()'" * tag 'cpu-to-thread_info-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: riscv: rely on core code to keep thread_info::cpu updated powerpc: smp: remove hack to obtain offset of task_struct::cpu sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y powerpc: add CPU field to struct thread_info s390: add CPU field to struct thread_info x86: add CPU field to struct thread_info arm64: add CPU field to struct thread_info
2021-10-20powerpc: Use of_get_cpu_hwid()Rob Herring
Replace open coded parsing of CPU nodes' 'reg' property with of_get_cpu_hwid(). Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211006164332.1981454-8-robh@kernel.org
2021-10-20powerpc/smp: do not decrement idle task preempt count in CPU offlineNathan Lynch
With PREEMPT_COUNT=y, when a CPU is offlined and then onlined again, we get: BUG: scheduling while atomic: swapper/1/0/0x00000000 no locks held by swapper/1/0. CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.15.0-rc2+ #100 Call Trace: dump_stack_lvl+0xac/0x108 __schedule_bug+0xac/0xe0 __schedule+0xcf8/0x10d0 schedule_idle+0x3c/0x70 do_idle+0x2d8/0x4a0 cpu_startup_entry+0x38/0x40 start_secondary+0x2ec/0x3a0 start_secondary_prolog+0x10/0x14 This is because powerpc's arch_cpu_idle_dead() decrements the idle task's preempt count, for reasons explained in commit a7c2bb8279d2 ("powerpc: Re-enable preemption before cpu_die()"), specifically "start_secondary() expects a preempt_count() of 0." However, since commit 2c669ef6979c ("powerpc/preempt: Don't touch the idle task's preempt_count during hotplug") and commit f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled"), that justification no longer holds. The idle task isn't supposed to re-enable preemption, so remove the vestigial preempt_enable() from the CPU offline path. Tested with pseries and powernv in qemu, and pseries on PowerVM. Fixes: 2c669ef6979c ("powerpc/preempt: Don't touch the idle task's preempt_count during hotplug") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211015173902.2278118-1-nathanl@linux.ibm.com
2021-09-30sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=yArd Biesheuvel
THREAD_INFO_IN_TASK moved the CPU field out of thread_info, but this causes some issues on architectures that define raw_smp_processor_id() in terms of this field, due to the fact that #include'ing linux/sched.h to get at struct task_struct is problematic in terms of circular dependencies. Given that thread_info and task_struct are the same data structure anyway when THREAD_INFO_IN_TASK=y, let's move it back so that having access to the type definition of struct thread_info is sufficient to reference the CPU number of the current task. Note that this requires THREAD_INFO_IN_TASK's definition of the task_thread_info() helper to be updated, as task_cpu() takes a pointer-to-const, whereas task_thread_info() (which is used to generate lvalues as well), needs a non-const pointer. So make it a macro instead. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
2021-08-27powerpc/numa: Update cpu_cpu_map on CPU online/offlineSrikar Dronamraju
cpu_cpu_map holds all the CPUs in the DIE. However in PowerPC, when onlining/offlining of CPUs, this mask doesn't get updated. This mask is however updated when CPUs are added/removed. So when both operations like online/offline of CPUs and adding/removing of CPUs are done simultaneously, then cpumaps end up broken. WARNING: CPU: 13 PID: 1142 at kernel/sched/topology.c:898 build_sched_domains+0xd48/0x1720 Modules linked in: rpadlpar_io rpaphp mptcp_diag xsk_diag tcp_diag udp_diag raw_diag inet_diag unix_diag af_packet_diag netlink_diag bonding tls nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set rfkill nf_tables nfnetlink pseries_rng xts vmx_crypto uio_pdrv_genirq uio binfmt_misc ip_tables xfs libcrc32c dm_service_time sd_mod t10_pi sg ibmvfc scsi_transport_fc ibmveth dm_multipath dm_mirror dm_region_hash dm_log dm_mod fuse CPU: 13 PID: 1142 Comm: kworker/13:2 Not tainted 5.13.0-rc6+ #28 Workqueue: events cpuset_hotplug_workfn NIP: c0000000001caac8 LR: c0000000001caac4 CTR: 00000000007088ec REGS: c00000005596f220 TRAP: 0700 Not tainted (5.13.0-rc6+) MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 48828222 XER: 00000009 CFAR: c0000000001ea698 IRQMASK: 0 GPR00: c0000000001caac4 c00000005596f4c0 c000000001c4a400 0000000000000036 GPR04: 00000000fffdffff c00000005596f1d0 0000000000000027 c0000018cfd07f90 GPR08: 0000000000000023 0000000000000001 0000000000000027 c0000018fe68ffe8 GPR12: 0000000000008000 c00000001e9d1880 c00000013a047200 0000000000000800 GPR16: c000000001d3c7d0 0000000000000240 0000000000000048 c000000010aacd18 GPR20: 0000000000000001 c000000010aacc18 c00000013a047c00 c000000139ec2400 GPR24: 0000000000000280 c000000139ec2520 c000000136c1b400 c000000001c93060 GPR28: c00000013a047c20 c000000001d3c6c0 c000000001c978a0 000000000000000d NIP [c0000000001caac8] build_sched_domains+0xd48/0x1720 LR [c0000000001caac4] build_sched_domains+0xd44/0x1720 Call Trace: [c00000005596f4c0] [c0000000001caac4] build_sched_domains+0xd44/0x1720 (unreliable) [c00000005596f670] [c0000000001cc5ec] partition_sched_domains_locked+0x3ac/0x4b0 [c00000005596f710] [c0000000002804e4] rebuild_sched_domains_locked+0x404/0x9e0 [c00000005596f810] [c000000000283e60] rebuild_sched_domains+0x40/0x70 [c00000005596f840] [c000000000284124] cpuset_hotplug_workfn+0x294/0xf10 [c00000005596fc60] [c000000000175040] process_one_work+0x290/0x590 [c00000005596fd00] [c0000000001753c8] worker_thread+0x88/0x620 [c00000005596fda0] [c000000000181704] kthread+0x194/0x1a0 [c00000005596fe10] [c00000000000ccec] ret_from_kernel_thread+0x5c/0x70 Instruction dump: 485af049 60000000 2fa30800 409e0028 80fe0000 e89a00f8 e86100e8 38da0120 7f88e378 7ce53b78 4801fb91 60000000 <0fe00000> 39000000 38e00000 38c00000 Fix this by updating cpu_cpu_map aka cpumask_of_node() on every CPU online/offline. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210826100521.412639-5-srikar@linux.vnet.ibm.com
2021-08-27powerpc/smp: Enable CACHE domain for shared processorSrikar Dronamraju
Currently CACHE domain is not enabled on shared processor mode PowerVM LPARS. On PowerVM systems, 'ibm,thread-group' device-tree property 2 under cpu-device-node indicates which all CPUs share L2-cache. However 'ibm,thread-group' device-tree property 2 is a relatively new property. In absence of 'ibm,thread-group' property 2, 'l2-cache' device property under cpu-device-node could help system to identify CPUs sharing L2-cache. However this property is not exposed by PhyP in shared processor mode configurations. In absence of properties that inform OS about which CPUs share L2-cache, fallback on core boundary. Here are some stats from Power9 shared LPAR with the changes. $ lscpu Architecture: ppc64le Byte Order: Little Endian CPU(s): 32 On-line CPU(s) list: 0-31 Thread(s) per core: 8 Core(s) per socket: 1 Socket(s): 3 NUMA node(s): 2 Model: 2.2 (pvr 004e 0202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 32K L1i cache: 32K NUMA node0 CPU(s): 16-23 NUMA node1 CPU(s): 0-15,24-31 Physical sockets: 2 Physical chips: 1 Physical cores/chip: 10 Before patch $ grep -r . /sys/kernel/debug/sched/domains/cpu0/domain*/name Before /sys/kernel/debug/sched/domains/cpu0/domain0/name:SMT /sys/kernel/debug/sched/domains/cpu0/domain1/name:DIE /sys/kernel/debug/sched/domains/cpu0/domain2/name:NUMA After /sys/kernel/debug/sched/domains/cpu0/domain0/name:SMT /sys/kernel/debug/sched/domains/cpu0/domain1/name:CACHE /sys/kernel/debug/sched/domains/cpu0/domain2/name:DIE /sys/kernel/debug/sched/domains/cpu0/domain3/name:NUMA $ awk '/domain/{print $1, $2}' /proc/schedstat | sort -u | sed -e 's/00000000,//g' Before domain0 00000055 domain0 000000aa domain0 00005500 domain0 0000aa00 domain0 00550000 domain0 00aa0000 domain0 55000000 domain0 aa000000 domain1 00ff0000 domain1 ff00ffff domain2 ffffffff After domain0 00000055 domain0 000000aa domain0 00005500 domain0 0000aa00 domain0 00550000 domain0 00aa0000 domain0 55000000 domain0 aa000000 domain1 000000ff domain1 0000ff00 domain1 00ff0000 domain1 ff000000 domain2 ff00ffff domain2 ffffffff domain3 ffffffff (Lower is better) perf stat -a -r 5 -n perf bench sched pipe | tail -n 2 Before 153.798 +- 0.142 seconds time elapsed ( +- 0.09% ) After 111.545 +- 0.652 seconds time elapsed ( +- 0.58% ) which is an improvement of 27.47% Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210826100401.412519-4-srikar@linux.vnet.ibm.com
generated by cgit (git 2.34.1) at 2025-07-25 21:57:41 +0000