Pull non-MM updates from Andrew Morton:
"Significant patch series in this pull request:
- "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
us closer to being able to remove page->mapping
- "relayfs: misc changes" (Jason Xing) does some maintenance and
minor feature addition work in relayfs
- "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
us from static preallocation of the kdump crashkernel's working
memory over to dynamic allocation. So the difficulty of a-priori
estimation of the second kernel's needs is removed and the first
kernel obtains extra memory
- "generalize panic_print's dump function to be used by other
kernel parts" (Feng Tang) implements some consolidation and
rationalization of the various ways in which a failing kernel
splats information at the operator
* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
tools/getdelays: add backward compatibility for taskstats version
kho: add test for kexec handover
delaytop: enhance error logging and add PSI feature description
samples: Kconfig: fix spelling mistake "instancess" -> "instances"
fat: fix too many log in fat_chain_add()
scripts/spelling.txt: add notifer||notifier to spelling.txt
xen/xenbus: fix typo "notifer"
net: mvneta: fix typo "notifer"
drm/xe: fix typo "notifer"
cxl: mce: fix typo "notifer"
KVM: x86: fix typo "notifer"
MAINTAINERS: add maintainers for delaytop
ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
ucount: fix atomic_long_inc_below() argument type
kexec: enable CMA based contiguous allocation
stackdepot: make max number of pools boot-time configurable
lib/xxhash: remove unused functions
init/Kconfig: restore CONFIG_BROKEN help text
lib/raid6: update recov_rvv.c zero page usage
docs: update docs after introducing delaytop
...
On do_exit() when a task is exiting, if a unwind is requested and the deferred user stacktrace is deferred via the task_work, the task_work callback is called after exit_mm() is called in do_exit(). This means that the user stack trace will not be retrieved and an empty stack is created. Instead, add a function unwind_deferred_task_exit() and call it just before exit_mm() so that the unwinder can call the requested callbacks with the user space stack. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Indu Bhagat <indu.bhagat@oracle.com> Cc: "Jose E. Marchesi" <jemarch@gnu.org> Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Jens Remus <jremus@linux.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Florian Weimer <fweimer@redhat.com> Cc: Sam James <sam@gentoo.org> Link: https://lore.kernel.org/20250729182406.504259474@kernel.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The commit 482a3767e508 ("exit: reparent: call forget_original_parent()
under tasklist_lock") moved the comment from exit_notify() to
forget_original_parent(). However, the forget_original_parent() only
handles (A), while (B) is handled in kill_orphaned_pgrp(). So remove the
unrelated part.
Link: https://lkml.kernel.org/r/20250615030930.58051-1-wangfushuai@baidu.com
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: wangfushuai <wangfushuai@baidu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull perf fixes from Borislav Petkov: - Avoid a crash on a heterogeneous machine where not all cores support the same hw events features - Avoid a deadlock when throttling events - Document the perf event states more - Make sure a number of perf paths switching off or rescheduling events call perf_cgroup_event_disable() - Make sure perf does task sampling before its userspace mapping is torn down, and not after * tag 'perf_urgent_for_v6.16_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Fix crash in icl_update_topdown_event() perf: Fix the throttle error of some clock events perf: Add comment to enum perf_event_state perf/core: Fix WARN in perf_cgroup_switch() perf: Fix dangling cgroup pointer in cpuctx perf: Fix cgroup state vs ERROR perf: Fix sample vs do_exit()
Baisheng Gao reported an ARM64 crash, which Mark decoded as being a
synchronous external abort -- most likely due to trying to access
MMIO in bad ways.
The crash further shows perf trying to do a user stack sample while in
exit_mmap()'s tlb_finish_mmu() -- i.e. while tearing down the address
space it is trying to access.
It turns out that we stop perf after we tear down the userspace mm; a
receipie for disaster, since perf likes to access userspace for
various reasons.
Flip this order by moving up where we stop perf in do_exit().
Additionally, harden PERF_SAMPLE_CALLCHAIN and PERF_SAMPLE_STACK_USER
to abort when the current task does not have an mm (exit_mm() makes
sure to set current->mm = NULL; before commencing with the actual
teardown). Such that CPU wide events don't trip on this same problem.
Fixes: c5ebcedb566e ("perf: Add ability to attach user stack dump to sample")
Reported-by: Baisheng Gao <baisheng.gao@unisoc.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250605110815.GQ39944@noisy.programming.kicks-ass.net
Pull non-MM updates from Andrew Morton:
- "hung_task: extend blocking task stacktrace dump to semaphore" from
Lance Yang enhances the hung task detector.
The detector presently dumps the blocking tasks's stack when it is
blocked on a mutex. Lance's series extends this to semaphores
- "nilfs2: improve sanity checks in dirty state propagation" from
Wentao Liang addresses a couple of minor flaws in nilfs2
- "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn
fixes a couple of issues in the gdb scripts
- "Support kdump with LUKS encryption by reusing LUKS volume keys" from
Coiby Xu addresses a usability problem with kdump.
When the dump device is LUKS-encrypted, the kdump kernel may not have
the keys to the encrypted filesystem. A full writeup of this is in
the series [0/N] cover letter
- "sysfs: add counters for lockups and stalls" from Max Kellermann adds
/sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and
/sys/kernel/rcu_stall_count
- "fork: Page operation cleanups in the fork code" from Pasha Tatashin
implements a number of code cleanups in fork.c
- "scripts/gdb/symbols: determine KASLR offset on s390 during early
boot" from Ilya Leoshkevich fixes some s390 issues in the gdb
scripts
* tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits)
llist: make llist_add_batch() a static inline
delayacct: remove redundant code and adjust indentation
squashfs: add optional full compressed block caching
crash_dump, nvme: select CONFIGFS_FS as built-in
scripts/gdb/symbols: determine KASLR offset on s390 during early boot
scripts/gdb/symbols: factor out pagination_off()
scripts/gdb/symbols: factor out get_vmlinux()
kernel/panic.c: format kernel-doc comments
mailmap: update and consolidate Casey Connolly's name and email
nilfs2: remove wbc->for_reclaim handling
fork: define a local GFP_VMAP_STACK
fork: check charging success before zeroing stack
fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code
fork: clean-up ifdef logic around stack allocation
kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count
kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count
x86/crash: make the page that stores the dm crypt keys inaccessible
x86/crash: pass dm crypt keys to kdump kernel
Revert "x86/mm: Remove unused __set_memory_prot()"
crash_dump: retrieve dm crypt keys in kdump kernel
...
Pull scheduler updates from Ingo Molnar:
"Core & fair scheduler changes:
- Tweak wait_task_inactive() to force dequeue sched_delayed tasks
(John Stultz)
- Adhere to place_entity() constraints (Peter Zijlstra)
- Allow decaying util_est when util_avg > CPU capacity (Pierre
Gondois)
- Fix up wake_up_sync() vs DELAYED_DEQUEUE (Xuewen Yan)
Energy management:
- Introduce sched_update_asym_prefer_cpu() (K Prateek Nayak)
- cpufreq/amd-pstate: Update asym_prefer_cpu when core rankings
change (K Prateek Nayak)
- Align uclamp and util_est and call before freq update (Xuewen Yan)
CPU isolation:
- Make use of more than one housekeeping CPU (Phil Auld)
RT scheduler:
- Fix race in push_rt_task() (Harshit Agarwal)
- Add kernel cmdline option for rt_group_sched (Michal Koutný)
Scheduler topology support:
- Improve topology_span_sane speed (Steve Wahl)
Scheduler debugging:
- Move and extend the sched_process_exit() tracepoint (Andrii
Nakryiko)
- Add RT_GROUP WARN checks for non-root task_groups (Michal Koutný)
- Fix trace_sched_switch(.prev_state) (Peter Zijlstra)
- Untangle cond_resched() and live-patching (Peter Zijlstra)
Fixes and cleanups:
- Misc fixes and cleanups (K Prateek Nayak, Michal Koutný, Peter
Zijlstra, Xuewen Yan)"
* tag 'sched-core-2025-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
sched/uclamp: Align uclamp and util_est and call before freq update
sched/util_est: Simplify condition for util_est_{en,de}queue()
sched/fair: Fixup wake_up_sync() vs DELAYED_DEQUEUE
sched,livepatch: Untangle cond_resched() and live-patching
sched/core: Tweak wait_task_inactive() to force dequeue sched_delayed tasks
sched/fair: Adhere to place_entity() constraints
sched/debug: Print the local group's asym_prefer_cpu
cpufreq/amd-pstate: Update asym_prefer_cpu when core rankings change
sched/topology: Introduce sched_update_asym_prefer_cpu()
sched/fair: Use READ_ONCE() to read sg->asym_prefer_cpu
sched/isolation: Make use of more than one housekeeping cpu
sched/rt: Fix race in push_rt_task
sched: Add annotations to RT_GROUP_SCHED fields
sched: Add RT_GROUP WARN checks for non-root task_groups
sched: Do not construct nor expose RT_GROUP_SCHED structures if disabled
sched: Bypass bandwitdh checks with runtime disabled RT_GROUP_SCHED
sched: Skip non-root task_groups with disabled RT_GROUP_SCHED
sched: Add commadline option for RT_GROUP_SCHED toggling
sched: Always initialize rt_rq's task_group
sched: Remove unneeed macro wrap
...
This reduces single-threaded overhead as it avoids one lock+irq trip on exit. It also improves scalability of spawning and killing threads within one process (just shy of 5% when doing it on 24 cores on my test jig). Both routines are moved below kcov and kmsan exit, which should be harmless. Link: https://lkml.kernel.org/r/20250319195436.1864415-1-mjguzik@gmail.com Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It is useful to be able to access current->mm at task exit to, say, record a bunch of VMA information right before the task exits (e.g., for stack symbolization reasons when dealing with short-lived processes that exit in the middle of profiling session). Currently, trace_sched_process_exit() is triggered after exit_mm() which resets current->mm to NULL making this tracepoint unsuitable for inspecting and recording task's mm_struct-related data when tracing process lifetimes. There is a particularly suitable place, though, right after taskstats_exit() is called, but before we do exit_mm() and other exit_*() resource teardowns. taskstats performs a similar kind of accounting that some applications do with BPF, and so co-locating them seems like a good fit. So that's where trace_sched_process_exit() is moved with this patch. Also, existing trace_sched_process_exit() tracepoint is notoriously missing `group_dead` flag that is certainly useful in practice and some of our production applications have to work around this. So plumb `group_dead` through while at it, to have a richer and more complete tracepoint. Note that we can't use sched_process_template anymore, and so we use TRACE_EVENT()-based tracepoint definition. But all the field names and order, as well as assign and output logic remain intact. We just add one extra field at the end in backwards-compatible way. [andrii@kernel.org: document sched_process_exit and sched_process_template relation] Link: https://lkml.kernel.org/r/20250403174120.4087794-1-andrii@kernel.org Link: https://lkml.kernel.org/r/20250402180925.90914-1-andrii@kernel.org Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Ingo Molnar <mingo@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After the commit 7903f907a2260 ("pid: perform free_pid() calls outside
of tasklist_lock") __unhash_process() -> detach_pid() no longer calls
free_pid(), proc_flush_pid() can just use p->thread_pid without the
now pointless get_pid() + put_pid().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/20250411121857.GA10550@redhat.com
Reviewed-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>