summaryrefslogtreecommitdiff
path: root/kernel/cpu.c
AgeCommit message (Collapse)AuthorFilesLines
2025-03-25Merge tag 'hyperv-next-signed-20250324' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Add support for running as the root partition in Hyper-V (Microsoft Hypervisor) by exposing /dev/mshv (Nuno and various people) - Add support for CPU offlining in Hyper-V (Hamza Mahfooz) - Misc fixes and cleanups (Roman Kisel, Tianyu Lan, Wei Liu, Michael Kelley, Thorsten Blum) * tag 'hyperv-next-signed-20250324' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits) x86/hyperv: fix an indentation issue in mshyperv.h x86/hyperv: Add comments about hv_vpset and var size hypercall input args Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs hyperv: Add definitions for root partition driver to hv headers x86: hyperv: Add mshv_handler() irq handler and setup function Drivers: hv: Introduce per-cpu event ring tail Drivers: hv: Export some functions for use by root partition module acpi: numa: Export node_to_pxm() hyperv: Introduce hv_recommend_using_aeoi() arm64/hyperv: Add some missing functions to arm64 x86/mshyperv: Add support for extended Hyper-V features hyperv: Log hypercall status codes as strings x86/hyperv: Fix check of return value from snp_set_vmsa() x86/hyperv: Add VTL mode callback for restarting the system x86/hyperv: Add VTL mode emergency restart callback hyperv: Remove unused union and structs hyperv: Add CONFIG_MSHV_ROOT to gate root partition support hyperv: Change hv_root_partition into a function hyperv: Convert hypercall statuses to linux error codes drivers/hv: add CPU offlining support ...
2025-03-06watchdog/hardlockup/perf: Fix perf_event memory leakLi Huafei1-5/+0
During stress-testing, we found a kmemleak report for perf_event: unreferenced object 0xff110001410a33e0 (size 1328): comm "kworker/4:11", pid 288, jiffies 4294916004 hex dump (first 32 bytes): b8 be c2 3b 02 00 11 ff 22 01 00 00 00 00 ad de ...;...."....... f0 33 0a 41 01 00 11 ff f0 33 0a 41 01 00 11 ff .3.A.....3.A.... backtrace (crc 24eb7b3a): [<00000000e211b653>] kmem_cache_alloc_node_noprof+0x269/0x2e0 [<000000009d0985fa>] perf_event_alloc+0x5f/0xcf0 [<00000000084ad4a2>] perf_event_create_kernel_counter+0x38/0x1b0 [<00000000fde96401>] hardlockup_detector_event_create+0x50/0xe0 [<0000000051183158>] watchdog_hardlockup_enable+0x17/0x70 [<00000000ac89727f>] softlockup_start_fn+0x15/0x40 ... Our stress test includes CPU online and offline cycles, and updating the watchdog configuration. After reading the code, I found that there may be a race between cleaning up perf_event after updating watchdog and disabling event when the CPU goes offline: CPU0 CPU1 CPU2 (update watchdog) (hotplug offline CPU1) ... _cpu_down(CPU1) cpus_read_lock() // waiting for cpu lock softlockup_start_all smp_call_on_cpu(CPU1) softlockup_start_fn ... watchdog_hardlockup_enable(CPU1) perf create E1 watchdog_ev[CPU1] = E1 cpus_read_unlock() cpus_write_lock() cpuhp_kick_ap_work(CPU1) cpuhp_thread_fun ... watchdog_hardlockup_disable(CPU1) watchdog_ev[CPU1] = NULL dead_event[CPU1] = E1 __lockup_detector_cleanup for each dead_events_mask release each dead_event /* * CPU1 has not been added to * dead_events_mask, then E1 * will not be released */ CPU1 -> dead_events_mask cpumask_clear(&dead_events_mask) // dead_events_mask is cleared, E1 is leaked In this case, the leaked perf_event E1 matches the perf_event leak reported by kmemleak. Due to the low probability of problem recurrence (only reported once), I added some hack delays in the code: static void __lockup_detector_reconfigure(void) { ... watchdog_hardlockup_start(); cpus_read_unlock(); + mdelay(100); /* * Must be called outside the cpus locked section to prevent * recursive locking in the perf code. ... } void watchdog_hardlockup_disable(unsigned int cpu) { ... perf_event_disable(event); this_cpu_write(watchdog_ev, NULL); this_cpu_write(dead_event, event); + mdelay(100); cpumask_set_cpu(smp_processor_id(), &dead_events_mask); atomic_dec(&watchdog_cpus); ... } void hardlockup_detector_perf_cleanup(void) { ... perf_event_release_kernel(event); per_cpu(dead_event, cpu) = NULL; } + mdelay(100); cpumask_clear(&dead_events_mask); } Then, simultaneously performing CPU on/off and switching watchdog, it is almost certain to reproduce this leak. The problem here is that releasing perf_event is not within the CPU hotplug read-write lock. Commit: 941154bd6937 ("watchdog/hardlockup/perf: Prevent CPU hotplug deadlock") introduced deferred release to solve the deadlock caused by calling get_online_cpus() when releasing perf_event. Later, commit: efe951d3de91 ("perf/x86: Fix perf,x86,cpuhp deadlock") removed the get_online_cpus() call on the perf_event release path to solve another deadlock problem. Therefore, it is now possible to move the release of perf_event back into the CPU hotplug read-write lock, and release the event immediately after disabling it. Fixes: 941154bd6937 ("watchdog/hardlockup/perf: Prevent CPU hotplug deadlock") Signed-off-by: Li Huafei <lihuafei1@huawei.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20241021193004.308303-1-lihuafei1@huawei.com
2025-02-13cpu: export lockdep_assert_cpus_held()Hamza Mahfooz1-0/+1
If CONFIG_HYPERV=m, lockdep_assert_cpus_held() is undefined for HyperV. So, export the function so that GPL drivers can use it more broadly. Cc: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20250117203309.192072-1-hamzamahfooz@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250117203309.192072-1-hamzamahfooz@linux.microsoft.com>
2025-01-26Merge tag 'mm-stable-2025-01-26-14-59' of ↵Linus Torvalds1-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "The various patchsets are summarized below. Plus of course many indivudual patches which are described in their changelogs. - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the page allocator so we end up with the ability to allocate and free zero-refcount pages. So that callers (ie, slab) can avoid a refcount inc & dec - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use large folios other than PMD-sized ones - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and fixes for this small built-in kernel selftest - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of the mapletree code - "mm: fix format issues and param types" from Keren Sun implements a few minor code cleanups - "simplify split calculation" from Wei Yang provides a few fixes and a test for the mapletree code - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes continues the work of moving vma-related code into the (relatively) new mm/vma.c - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David Hildenbrand cleans up and rationalizes handling of gfp flags in the page allocator - "readahead: Reintroduce fix for improper RA window sizing" from Jan Kara is a second attempt at fixing a readahead window sizing issue. It should reduce the amount of unnecessary reading - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng addresses an issue where "huge" amounts of pte pagetables are accumulated: https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/ Qi's series addresses this windup by synchronously freeing PTE memory within the context of madvise(MADV_DONTNEED) - "selftest/mm: Remove warnings found by adding compiler flags" from Muhammad Usama Anjum fixes some build warnings in the selftests code when optional compiler warnings are enabled - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David Hildenbrand tightens the allocator's observance of __GFP_HARDWALL - "pkeys kselftests improvements" from Kevin Brodsky implements various fixes and cleanups in the MM selftests code, mainly pertaining to the pkeys tests - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to estimate application working set size - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn provides some cleanups to memcg's hugetlb charging logic - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based kernel build was demonstrated - "zram: split page type read/write handling" from Sergey Senozhatsky has several fixes and cleaups for zram in the area of zram_write_page(). A watchdog softlockup warning was eliminated - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky cleans up the pagetable destructor implementations. A rare use-after-free race is fixed - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes simplifies and cleans up the debugging code in the VMA merging logic - "Account page tables at all levels" from Kevin Brodsky cleans up and regularizes the pagetable ctor/dtor handling. This results in improvements in accounting accuracy - "mm/damon: replace most damon_callback usages in sysfs with new core functions" from SeongJae Park cleans up and generalizes DAMON's sysfs file interface logic - "mm/damon: enable page level properties based monitoring" from SeongJae Park increases the amount of information which is presented in response to DAMOS actions - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs is completed - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter Xu cleans up and generalizes the hugetlb reservation accounting - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino removes a never-used feature of the alloc_pages_bulk() interface - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park extends DAMOS filters to support not only exclusion (rejecting), but also inclusion (allowing) behavior - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi introduces a new memory descriptor for zswap.zpool that currently overlaps with struct page for now. This is part of the effort to reduce the size of struct page and to enable dynamic allocation of memory descriptors - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and simplifies the swap allocator locking. A speedup of 400% was demonstrated for one workload. As was a 35% reduction for kernel build time with swap-on-zram - "mm: update mips to use do_mmap(), make mmap_region() internal" from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that mmap_region() can be made MM-internal - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU regressions and otherwise improves MGLRU performance - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park updates DAMON documentation - "Cleanup for memfd_create()" from Isaac Manjarres does that thing - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand provides various cleanups in the areas of hugetlb folios, THP folios and migration - "Uncached buffered IO" from Jens Axboe implements the new RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache reading and writing. To permite userspace to address issues with massive buildup of useless pagecache when reading/writing fast devices - "selftests/mm: virtual_address_range: Reduce memory" from Thomas Weißschuh fixes and optimizes some of the MM selftests" * tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm/compaction: fix UBSAN shift-out-of-bounds warning s390/mm: add missing ctor/dtor on page table upgrade kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags() tools: add VM_WARN_ON_VMG definition mm/damon/core: use str_high_low() helper in damos_wmark_wait_us() seqlock: add missing parameter documentation for raw_seqcount_try_begin() mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh mm/page_alloc: remove the incorrect and misleading comment zram: remove zcomp_stream_put() from write_incompressible_page() mm: separate move/undo parts from migrate_pages_batch() mm/kfence: use str_write_read() helper in get_access_type() selftests/mm/mkdirty: fix memory leak in test_uffdio_copy() kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags() selftests/mm: virtual_address_range: avoid reading from VM_IO mappings selftests/mm: vm_util: split up /proc/self/smaps parsing selftests/mm: virtual_address_range: unmap chunks after validation selftests/mm: virtual_address_range: mmap() without PROT_WRITE selftests/memfd/memfd_test: fix possible NULL pointer dereference mm: add FGP_DONTCACHE folio creation flag mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue ...
2025-01-26Merge tag 'bitmap-for-6.14' of https://github.com:/norov/linuxLinus Torvalds1-5/+0
Pull bitmap updates from Yury Norov: "This includes const_true() series from Vincent Mailhol, another __always_inline rework from Nathan Chancellor for RISCV, and a couple of random fixes from Dr. David Alan Gilbert and I Hsin Cheng" * tag 'bitmap-for-6.14' of https://github.com:/norov/linux: cpumask: Rephrase comments for cpumask_any*() APIs cpu: Remove unused init_cpu_online riscv: Always inline bitops linux/bits.h: simplify GENMASK_INPUT_CHECK() compiler.h: add const_true()
2025-01-16hrtimers: Handle CPU state correctly on hotplugKoichiro Den1-1/+1
Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to CPUHP_ONLINE: Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set to 1 throughout. However, during a CPU unplug operation, the tick and the clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online state, for instance CFS incorrectly assumes that the hrtick is already active, and the chance of the clockevent device to transition to oneshot mode is also lost forever for the CPU, unless it goes back to a lower state than CPUHP_HRTIMERS_PREPARE once. This round-trip reveals another issue; cpu_base.online is not set to 1 after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer(). Aside of that, the bulk of the per CPU state is not reset either, which means there are dangling pointers in the worst case. Address this by adding a corresponding startup() callback, which resets the stale per CPU state and sets the online flag. [ tglx: Make the new callback unconditionally available, remove the online modification in the prepare() callback and clear the remaining state in the starting callback instead of the prepare callback ] Fixes: 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier") Signed-off-by: Koichiro Den <koichiro.den@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20241220134421.3809834-1-koichiro.den@canonical.com
2025-01-13lazy tlb: fix hotplug exit race with MMU_LAZY_TLB_SHOOTDOWNNicholas Piggin1-4/+5
CPU unplug first calls __cpu_disable(), and that's where powerpc calls cleanup_cpu_mmu_context(), which clears this CPU from mm_cpumask() of all mms in the system. However this CPU may still be using a lazy tlb mm, and its mm_cpumask bit will be cleared from it. The CPU does not switch away from the lazy tlb mm until arch_cpu_idle_dead() calls idle_task_exit(). If that user mm exits in this window, it will not be subject to the lazy tlb mm shootdown and may be freed while in use as a lazy mm by the CPU that is being unplugged. cleanup_cpu_mmu_context() could be moved later, but it looks better to move the lazy tlb mm switching earlier. The problem with doing the lazy mm switching in idle_task_exit() is explained in commit bf2c59fce4074 ("sched/core: Fix illegal RCU from offline CPUs"), which added a wart to switch away from the mm but leave it set in active_mm to be cleaned up later. So instead, switch away from the lazy tlb mm at sched_cpu_wait_empty(), which is the last hotplug state before teardown (CPUHP_AP_SCHED_WAIT_EMPTY). This CPU will never switch to a user thread from this point, so it has no chance to pick up a new lazy tlb mm. This removes the lazy tlb mm handling wart in CPU unplug. With this, idle_task_exit() is not needed anymore and can be cleaned up. This leaves the prototype alone, to be cleaned after this change. herton: took the suggestions from https://lore.kernel.org/all/87jzvyprsw.ffs@tglx/ and made adjustments on the initial patch proposed by Nicholas. Link: https://lkml.kernel.org/r/20230524060455.147699-1-npiggin@gmail.com Link: https://lore.kernel.org/all/20230525205253.E2FAEC433EF@smtp.kernel.org/ Link: https://lkml.kernel.org/r/20241104142318.3295663-1-herton@redhat.com Fixes: 2655421ae69f ("lazy tlb: shoot lazies, non-refcounting lazy tlb mm reference handling scheme") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-30cpu: Remove unused init_cpu_onlineDr. David Alan Gilbert1-5/+0
The last use of init_cpu_online() was removed by the commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture") Remove it. Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Signed-off-by: Yury Norov <yury.norov@gmail.com>
2024-11-29Merge tag 'driver-core-6.13-rc1' of ↵Linus Torvalds1-3/+0
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is a small set of driver core changes for 6.13-rc1. Nothing major for this merge cycle, except for the two simple merge conflicts are here just to make life interesting. Included in here are: - sysfs core changes and preparations for more sysfs api cleanups that can come through all driver trees after -rc1 is out - fw_devlink fixes based on many reports and debugging sessions - list_for_each_reverse() removal, no one was using it! - last-minute seq_printf() format string bug found and fixed in many drivers all at once. - minor bugfixes and changes full details in the shortlog" * tag 'driver-core-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (35 commits) Fix a potential abuse of seq_printf() format string in drivers cpu: Remove spurious NULL in attribute_group definition s390/con3215: Remove spurious NULL in attribute_group definition perf: arm-ni: Remove spurious NULL in attribute_group definition driver core: Constify bin_attribute definitions sysfs: attribute_group: allow registration of const bin_attribute firmware_loader: Fix possible resource leak in fw_log_firmware_info() drivers: core: fw_devlink: Fix excess parameter description in docstring driver core: class: Correct WARN() message in APIs class_(for_each|find)_device() cacheinfo: Use of_property_present() for non-boolean properties cdx: Fix cdx_mmap_resource() after constifying attr in ->mmap() drivers: core: fw_devlink: Make the error message a bit more useful phy: tegra: xusb: Set fwnode for xusb port devices drm: display: Set fwnode for aux bus devices driver core: fw_devlink: Stop trying to optimize cycle detection logic driver core: Constify attribute arguments of binary attributes sysfs: bin_attribute: add const read/write callback variants sysfs: implement all BIN_ATTR_* macros in terms of __BIN_ATTR() sysfs: treewide: constify attribute callback of bin_attribute::llseek() sysfs: treewide: constify attribute callback of bin_attribute::mmap() ...
2024-11-19Merge tag 'timers-core-2024-11-18' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "A rather large update for timekeeping and timers: - The final step to get rid of auto-rearming posix-timers posix-timers are currently auto-rearmed by the kernel when the signal of the timer is ignored so that the timer signal can be delivered once the corresponding signal is unignored. This requires to throttle the timer to prevent a DoS by small intervals and keeps the system pointlessly out of low power states for no value. This is a long standing non-trivial problem due to the lock order of posix-timer lock and the sighand lock along with life time issues as the timer and the sigqueue have different life time rules. Cure this by: - Embedding the sigqueue into the timer struct to have the same life time rules. Aside of that this also avoids the lookup of the timer in the signal delivery and rearm path as it's just a always valid container_of() now. - Queuing ignored timer signals onto a seperate ignored list. - Moving queued timer signals onto the ignored list when the signal is switched to SIG_IGN before it could be delivered. - Walking the ignored list when SIG_IGN is lifted and requeue the signals to the actual signal lists. This allows the signal delivery code to rearm the timer. This also required to consolidate the signal delivery rules so they are consistent across all situations. With that all self test scenarios finally succeed. - Core infrastructure for VFS multigrain timestamping This is required to allow the kernel to use coarse grained time stamps by default and switch to fine grained time stamps when inode attributes are actively observed via getattr(). These changes have been provided to the VFS tree as well, so that the VFS specific infrastructure could be built on top. - Cleanup and consolidation of the sleep() infrastructure - Move all sleep and timeout functions into one file - Rework udelay() and ndelay() into proper documented inline functions and replace the hardcoded magic numbers by proper defines. - Rework the fsleep() implementation to take the reality of the timer wheel granularity on different HZ values into account. Right now the boundaries are hard coded time ranges which fail to provide the requested accuracy on different HZ settings. - Update documentation for all sleep/timeout related functions and fix up stale documentation links all over the place - Fixup a few usage sites - Rework of timekeeping and adjtimex(2) to prepare for multiple PTP clocks A system can have multiple PTP clocks which are participating in seperate and independent PTP clock domains. So far the kernel only considers the PTP clock which is based on CLOCK TAI relevant as that's the clock which drives the timekeeping adjustments via the various user space daemons through adjtimex(2). The non TAI based clock domains are accessible via the file descriptor based posix clocks, but their usability is very limited. They can't be accessed fast as they always go all the way out to the hardware and they cannot be utilized in the kernel itself. As Time Sensitive Networking (TSN) gains traction it is required to provide fast user and kernel space access to these clocks. The approach taken is to utilize the timekeeping and adjtimex(2) infrastructure to provide this access in a similar way how the kernel provides access to clock MONOTONIC, REALTIME etc. Instead of creating a duplicated infrastructure this rework converts timekeeping and adjtimex(2) into generic functionality which operates on pointers to data structures instead of using static variables. This allows to provide time accessors and adjtimex(2) functionality for the independent PTP clocks in a subsequent step. - Consolidate hrtimer initialization hrtimers are set up by initializing the data structure and then seperately setting the callback function for historical reasons. That's an extra unnecessary step and makes Rust support less straight forward than it should be. Provide a new set of hrtimer_setup*() functions and convert the core code and a few usage sites of the less frequently used interfaces over. The bulk of the htimer_init() to hrtimer_setup() conversion is already prepared and scheduled for the next merge window. - Drivers: - Ensure that the global timekeeping clocksource is utilizing the cluster 0 timer on MIPS multi-cluster systems. Otherwise CPUs on different clusters use their cluster specific clocksource which is not guaranteed to be synchronized with other clusters. - Mostly boring cleanups, fixes, improvements and code movement" * tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits) posix-timers: Fix spurious warning on double enqueue versus do_exit() clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties clocksource/drivers/gpx: Remove redundant casts clocksource/drivers/timer-ti-dm: Fix child node refcount handling dt-bindings: timer: actions,owl-timer: convert to YAML clocksource/drivers/ralink: Add Ralink System Tick Counter driver clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource clocksource/drivers/timer-ti-dm: Don't fail probe if int not found clocksource/drivers:sp804: Make user selectable clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions hrtimers: Delete hrtimer_init_on_stack() alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack() io_uring: Switch to use hrtimer_setup_on_stack() sched/idle: Switch to use hrtimer_setup_on_stack() hrtimers: Delete hrtimer_init_sleeper_on_stack() wait: Switch to use hrtimer_setup_sleeper_on_stack() timers: Switch to use hrtimer_setup_sleeper_on_stack() net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack() futex: Switch to use hrtimer_setup_sleeper_on_stack() fs/aio: Switch to use hrtimer_setup_sleeper_on_stack() ...
2024-11-18cpu: Remove spurious NULL in attribute_group definitionThomas Weißschuh1-3/+0
This NULL value is most-likely a copy-paste error from an array definition. The NULL doesn't have any effect. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20241118-sysfs-const-attribute_group-fixes-v1-3-48e0b0ad8cba@weissschuh.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-31clockevents: Shutdown and unregister current clockevents at CPUHP_AP_TICK_DYINGFrederic Weisbecker1-2/+0
The way the clockevent devices are finally stopped while a CPU is offlining is currently chaotic. The layout being by order: 1) tick_sched_timer_dying() stops the tick and the underlying clockevent but only for oneshot case. The periodic tick and its related clockevent still runs. 2) tick_broadcast_offline() detaches and stops the per-cpu oneshot broadcast and append it to the released list. 3) Some individual clockevent drivers stop the clockevents (a second time if the tick is oneshot) 4) Once the CPU is dead, a control CPU remotely detaches and stops (a 3rd time if oneshot mode) the CPU clockevent and adds it to the released list. 5) The released list containing the broadcast device released on step 2) and the remotely detached clockevent from step 4) are unregistered. These random events can be factorized if the current clockevent is detached and stopped by the dying CPU at the generic layer, that is from the dying CPU: a) Stop the tick b) Stop/detach the underlying per-cpu oneshot broadcast clockevent c) Stop/detach the underlying clockevent d) Release / unregister the clockevents from b) and c) e) Release / unregister the remaining clockevents from the dying CPU. This part could be performed by the dying CPU This way the drivers and the tick layer don't need to care about clockevent operations during cpuhotplug down. This also unifies the tick behaviour on offline CPUs between oneshot and periodic modes, avoiding offline ticks altogether for sanity. Adopt the simplification. [ tglx: Remove the WARN_ON() in clockevents_register_device() as that is called from an upcoming CPU before the CPU is marked online ] Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241029125451.54574-3-frederic@kernel.org
2024-10-17lockdep: Add lockdep_cleanup_dead_cpu()David Woodhouse1-0/+1
Add a function to check that an offline CPU has left the tracing infrastructure in a sane state. Commit 9bb69ba4c177 ("ACPI: processor_idle: use raw_safe_halt() in acpi_idle_play_dead()") fixed an issue where the acpi_idle_play_dead() function called safe_halt() instead of raw_safe_halt(), which had the side-effect of setting the hardirqs_enabled flag for the offline CPU. On x86 this triggered warnings from lockdep_assert_irqs_disabled() when the CPU was brought back online again later. These warnings were too early for the exception to be handled correctly, leading to a triple-fault. Add lockdep_cleanup_dead_cpu() to check for this kind of failure mode, print the events leading up to it, and correct it so that the CPU can come online again correctly. Re-introducing the original bug now merely results in this warning instead: [ 61.556652] smpboot: CPU 1 is now offline [ 61.556769] CPU 1 left hardirqs enabled! [ 61.556915] irq event stamp: 128149 [ 61.556965] hardirqs last enabled at (128149): [<ffffffff81720a36>] acpi_idle_play_dead+0x46/0x70 [ 61.557055] hardirqs last disabled at (128148): [<ffffffff81124d50>] do_idle+0x90/0xe0 [ 61.557117] softirqs last enabled at (128078): [<ffffffff81cec74c>] __do_softirq+0x31c/0x423 [ 61.557199] softirqs last disabled at (128065): [<ffffffff810baae1>] __irq_exit_rcu+0x91/0x100 [boqun: Capitalize the title and reword the message a bit] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/f7bd2b3b999051bb3ef4be34526a9262008285f5.camel@infradead.org
2024-09-17Merge tag 'timers-core-2024-09-16' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Core: - Overhaul of posix-timers in preparation of removing the workaround for periodic timers which have signal delivery ignored. - Remove the historical extra jiffie in msleep() msleep() adds an extra jiffie to the timeout value to ensure minimal sleep time. The timer wheel ensures minimal sleep time since the large rewrite to a non-cascading wheel, but the extra jiffie in msleep() remained unnoticed. Remove it. - Make the timer slack handling correct for realtime tasks. The procfs interface is inconsistent and does neither reflect reality nor conforms to the man page. Show the correct 0 slack for real time tasks and enforce it at the core level instead of having inconsistent individual checks in various timer setup functions. - The usual set of updates and enhancements all over the place. Drivers: - Allow the ACPI PM timer to be turned off during suspend - No new drivers - The usual updates and enhancements in various drivers" * tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits) ntp: Make sure RTC is synchronized when time goes backwards treewide: Fix wrong singular form of jiffies in comments cpu: Use already existing usleep_range() timers: Rename next_expiry_recalc() to be unique platform/x86:intel/pmc: Fix comment for the pmc_core_acpi_pm_timer_suspend_resume function clocksource/drivers/jcore: Use request_percpu_irq() clocksource/drivers/cadence-ttc: Add missing clk_disable_unprepare in ttc_setup_clockevent clocksource/drivers/asm9260: Add missing clk_disable_unprepare in asm9260_timer_init clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init() clocksource/drivers/ingenic: Use devm_clk_get_enabled() helpers platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended clocksource: acpi_pm: Add external callback for suspend/resume clocksource/drivers/arm_arch_timer: Using for_each_available_child_of_node_scoped() dt-bindings: timer: rockchip: Add rk3576 compatible timers: Annotate possible non critical data race of next_expiry timers: Remove historical extra jiffie for timeout in msleep() hrtimer: Use and report correct timerslack values for realtime tasks hrtimer: Annotate hrtimer_cpu_base_.*_expiry() for sparse. timers: Add sparse annotation for timer_sync_wait_running(). signal: Replace BUG_ON()s ...
2024-09-10Merge branch 'linus' into timers/coreThomas Gleixner1-1/+11
To update with the latest fixes.
2024-09-08cpu: Use already existing usleep_range()Anna-Maria Behnsen1-1/+1
usleep_range() is a wrapper arount usleep_range_state() which hands in TASK_UNTINTERRUPTIBLE as state argument. Use already exising wrapper usleep_range(). No functional change. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/all/20240904-devel-anna-maria-b4-timers-flseep-v1-2-e98760256370@linutronix.de
2024-09-04cpu: Fix W=1 build kernel-doc warningThorsten Blum1-3/+1
Building the kernel with W=1 generates the following warning: kernel/cpu.c:2693: warning: This comment starts with '/**', but isn't a kernel-doc comment. The function topology_is_core_online() is a simple helper function and doesn't need a kernel-doc comment. Use a normal comment instead. Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240825221152.71951-2-thorsten.blum@toblux.com
2024-09-04Merge branch 'linus' into smp/coreThomas Gleixner1-1/+11
Pull in upstream changes so further patches don't conflict.
2024-08-13cpu/SMT: Enable SMT only if a core is onlineNysal Jan K.A1-1/+11
If a core is offline then enabling SMT should not online CPUs of this core. By enabling SMT, what is intended is either changing the SMT value from "off" to "on" or setting the SMT level (threads per core) from a lower to higher value. On PowerPC the ppc64_cpu utility can be used, among other things, to perform the following functions: ppc64_cpu --cores-on # Get the number of online cores ppc64_cpu --cores-on=X # Put exactly X cores online ppc64_cpu --offline-cores=X[,Y,...] # Put specified cores offline ppc64_cpu --smt={on|off|value} # Enable, disable or change SMT level If the user has decided to offline certain cores, enabling SMT should not online CPUs in those cores. This patch fixes the issue and changes the behaviour as described, by introducing an arch specific function topology_is_core_online(). It is currently implemented only for PowerPC. Fixes: 73c58e7e1412 ("powerpc: Add HOTPLUG_SMT support") Reported-by: Tyrel Datwyler <tyreld@linux.ibm.com> Closes: https://groups.google.com/g/powerpc-utils-devel/c/wrwVzAAnRlI/m/5KJSoqP4BAAJ Signed-off-by: Nysal Jan K.A <nysal@linux.ibm.com> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240731030126.956210-2-nysal@linux.ibm.com
2024-08-02cpu/hotplug: Provide weak fallback for arch_cpuhp_init_parallel_bringup()Jiaxun Yang1-0/+5
CONFIG_HOTPLUG_PARALLEL expects the architecture to implement arch_cpuhp_init_parallel_bringup() to decide whether paralllel hotplug is possible and to do the necessary architecture specific initialization. There are architectures which can enable it unconditionally and do not require architecture specific initialization. Provide a weak fallback for arch_cpuhp_init_parallel_bringup() so that such architectures are not forced to implement empty stub functions. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240716-loongarch-hotplug-v3-2-af59b3bb35c8@flygoat.com
2024-08-02cpu/hotplug: Make HOTPLUG_PARALLEL independent of HOTPLUG_SMTJiaxun Yang1-0/+11
Provide stub functions for SMT related parallel bring up functions so that HOTPLUG_PARALLEL can work without HOTPLUG_SMT. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240716-loongarch-hotplug-v3-1-af59b3bb35c8@flygoat.com
2024-07-15Merge tag 'x86_cc_for_v6.11_rc1' of ↵Linus Torvalds1-1/+11
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 confidential computing updates from Borislav Petkov: "Unrelated x86/cc changes queued here to avoid ugly cross-merges and conflicts: - Carve out CPU hotplug function declarations into a separate header with the goal to be able to use the lockdep assertions in a more flexible manner - As a result, refactor cacheinfo code after carving out a function to return the cache ID associated with a given cache level - Cleanups Add support to be able to kexec TDX guests: - Expand ACPI MADT CPU offlining support - Add machinery to prepare CoCo guests memory before kexec-ing into a new kernel - Cleanup, readjust and massage related code" * tag 'x86_cc_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) ACPI: tables: Print MULTIPROC_WAKEUP when MADT is parsed x86/acpi: Add support for CPU offlining for ACPI MADT wakeup method x86/mm: Introduce kernel_ident_mapping_free() x86/smp: Add smp_ops.stop_this_cpu() callback x86/acpi: Do not attempt to bring up secondary CPUs in the kexec case x86/acpi: Rename fields in the acpi_madt_multiproc_wakeup structure x86/mm: Do not zap page table entries mapping unaccepted memory table during kdump x86/mm: Make e820__end_ram_pfn() cover E820_TYPE_ACPI ranges x86/tdx: Convert shared memory back to private on kexec x86/mm: Add callbacks to prepare encrypted memory for kexec x86/tdx: Account shared memory x86/mm: Return correct level from lookup_address() if pte is none x86/mm: Make x86_platform.guest.enc_status_change_*() return an error x86/kexec: Keep CR4.MCE set during kexec for TDX guest x86/relocate_kernel: Use named labels for less confusion cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup cpu/hotplug: Add support for declaring CPU offlining not supported x86/apic: Mark acpi_mp_wake_* variables as __ro_after_init x86/acpi: Extract ACPI MADT wakeup code into a separate file x86/kexec: Remove spurious unconditional JMP from from identity_mapped() ...
2024-07-15Merge tag 'arm64-upstream' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "The biggest part is the virtual CPU hotplug that touches ACPI, irqchip. We also have some GICv3 optimisation for pseudo-NMIs that has been queued via the arm64 tree. Otherwise the usual perf updates, kselftest, various small cleanups. Core: - Virtual CPU hotplug support for arm64 ACPI systems - cpufeature infrastructure cleanups and making the FEAT_ECBHB ID bits visible to guests - CPU errata: expand the speculative SSBS workaround to more CPUs - GICv3, use compile-time PMR values: optimise the way regular IRQs are masked/unmasked when GICv3 pseudo-NMIs are used, removing the need for a static key in fast paths by using a priority value chosen dynamically at boot time ACPI: - 'acpi=nospcr' option to disable SPCR as default console for arm64 - Move some ACPI code (cpuidle, FFH) to drivers/acpi/arm64/ Perf updates: - Rework of the IMX PMU driver to enable support for I.MX95 - Enable support for tertiary match groups in the CMN PMU driver - Initial refactoring of the CPU PMU code to prepare for the fixed instruction counter introduced by Arm v9.4 - Add missing PMU driver MODULE_DESCRIPTION() strings - Hook up DT compatibles for recent CPU PMUs Kselftest updates: - Kernel mode NEON fp-stress - Cleanups, spelling mistakes Miscellaneous: - arm64 Documentation update with a minor clarification on TBI - Fix missing IPI statistics - Implement raw_smp_processor_id() using thread_info rather than a per-CPU variable (better code generation) - Make MTE checking of in-kernel asynchronous tag faults conditional on KASAN being enabled - Minor cleanups, typos" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (69 commits) selftests: arm64: tags: remove the result script selftests: arm64: tags_test: conform test to TAP output perf: add missing MODULE_DESCRIPTION() macros arm64: smp: Fix missing IPI statistics irqchip/gic-v3: Fix 'broken_rdists' unused warning when !SMP and !ACPI ACPI: Add acpi=nospcr to disable ACPI SPCR as default console on ARM64 Documentation: arm64: Update memory.rst for TBI arm64/cpufeature: Replace custom macros with fields from ID_AA64PFR0_EL1 KVM: arm64: Replace custom macros with fields from ID_AA64PFR0_EL1 perf: arm_pmuv3: Include asm/arm_pmuv3.h from linux/perf/arm_pmuv3.h perf: arm_v6/7_pmu: Drop non-DT probe support perf/arm: Move 32-bit PMU drivers to drivers/perf/ perf: arm_pmuv3: Drop unnecessary IS_ENABLED(CONFIG_ARM64) check perf: arm_pmuv3: Avoid assigning fixed cycle counter with threshold arm64: Kconfig: Fix dependencies to enable ACPI_HOTPLUG_CPU perf: imx_perf: add support for i.MX95 platform perf: imx_perf: fix counter start and config sequence perf: imx_perf: refactor driver for imx93 perf: imx_perf: let the driver manage the counter usage rather the user perf: imx_perf: add macro definitions for parsing config attr ...
2024-07-15Merge tag 'smp-core-2024-07-14' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull CPU hotplug updates from Thomas Gleixner: "A small set of SMP/CPU hotplug updates: - Reverse the order of iteration when freezing secondary CPUs for hibernation. This avoids that drivers like the Intel uncore performance counter have to transfer the assignement of handling the per package uncore events for every CPU in a package, which is a considerable speedup on larger systems. - Add a missing destroy_work_on_stack() invocation in smp_call_on_cpu() to prevent debug objects to emit a false positive warning when the stack is freed. - Small cleanups in comments and a str_plural() conversion" * tag 'smp-core-2024-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu() cpu/hotplug: Reverse order of iteration in freeze_secondary_cpus() smp: Use str_plural() to fix Coccinelle warnings cpu/hotplug: Fix typo in comment
2024-06-28cpumask: Add enabled cpumask for present CPUs that can be brought onlineJames Morse1-0/+3
The 'offline' file in sysfs shows all offline CPUs, including those that aren't present. User-space is expected to remove not-present CPUs from this list to learn which CPUs could be brought online. CPUs can be present but not-enabled. These CPUs can't be brought online until the firmware policy changes, which comes with an ACPI notification that will register the CPUs. With only the offline and present files, user-space is unable to determine which CPUs it can try to bring online. Add a new CPU mask that shows this based on all the registered CPUs. Signed-off-by: James Morse <james.morse@arm.com> Tested-by: Miguel Luis <miguel.luis@oracle.com> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> Tested-by: Jianyong Wu <jianyong.wu@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20240529133446.28446-20-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-06-23cpu: Fix broken cmdline "nosmp" and "maxcpus=0"Huacai Chen1-0/+3
After the rework of "Parallel CPU bringup", the cmdline "nosmp" and "maxcpus=0" parameters are not working anymore. These parameters set setup_max_cpus to zero and that's handed to bringup_nonboot_cpus(). The code there does a decrement before checking for zero, which brings it into the negative space and brings up all CPUs. Add a zero check at the beginning of the function to prevent this. [ tglx: Massaged change log ] Fixes: 18415f33e2ac4ab382 ("cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE") Fixes: 06c6796e0304234da6 ("cpu/hotplug: Fix off by one in cpuhp_bringup_mask()") Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240618081336.3996825-1-chenhuacai@loongson.cn
2024-06-17cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeupKirill A. Shutemov1-2/+1
ACPI MADT doesn't allow to offline a CPU after it has been woken up. Currently, CPU hotplug is prevented based on the confidential computing attribute which is set for Intel TDX. But TDX is not the only possible user of the wake up method. Any platform that uses ACPI MADT wakeup method cannot offline CPU. Disable CPU offlining on ACPI MADT wakeup enumeration. This has no visible effects for users: currently, TDX guest is the only platform that uses the ACPI MADT wakeup method. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Tao Liu <ltao@redhat.com> Link: https://lore.kernel.org/r/20240614095904.1345461-5-kirill.shutemov@linux.intel.com
2024-06-17cpu/hotplug: Add support for declaring CPU offlining not supportedKirill A. Shutemov1-1/+12
The ACPI MADT mailbox wakeup method doesn't allow to offline a CPU after it has been woken up. Currently, offlining is prevented based on the confidential computing attribute which is set for Intel TDX. But TDX is not the only possible user of the wake up method. The MADT wakeup can be implemented outside of a confidential computing environment. Offline support is a property of the wakeup method, not the CoCo implementation. Introduce cpu_hotplug_disable_offlining() that can be called to indicate that CPU offlining should be disabled. This function is going to replace CC_ATTR_HOTPLUG_DISABLED for ACPI MADT wakeup method. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Tao Liu <ltao@redhat.com> Link: https://lore.kernel.org/r/20240614095904.1345461-4-kirill.shutemov@linux.intel.com
2024-06-17cpu/hotplug: Reverse order of iteration in freeze_secondary_cpus()Stanislav Spassov1-2/+2
Whenever CPU hotplug state callbacks are registered, the startup callback is invoked on CPUs that have already reached the provided state in order of ascending CPU IDs. In freeze_secondary_cpus() the teardown of CPUs hap