linux/kernel
Mathieu Desnoyers 9a4f1dc8a1 tracepoint: Use rcu get state and cond sync for static call updates
commit 7b40066c97 upstream.

State transitions from 1->0->1 and N->2->1 callbacks require RCU
synchronization. Rather than performing the RCU synchronization every
time the state change occurs, which is quite slow when many tracepoints
are registered in batch, instead keep a snapshot of the RCU state on the
most recent transitions which belong to a chain, and conditionally wait
for a grace period on the last transition of the chain if one g.p. has
not elapsed since the last snapshot.

This applies to both RCU and SRCU.

This brings the performance regression caused by commit 231264d692
("Fix: tracepoint: static call function vs data state mismatch") back to
what it was originally.

Before this commit:

  # trace-cmd start -e all
  # time trace-cmd start -p nop

  real	0m10.593s
  user	0m0.017s
  sys	0m0.259s

After this commit:

  # trace-cmd start -e all
  # time trace-cmd start -p nop

  real	0m0.878s
  user	0m0.000s
  sys	0m0.103s

Link: https://lkml.kernel.org/r/20210805192954.30688-1-mathieu.desnoyers@efficios.com
Link: https://lore.kernel.org/io-uring/4ebea8f0-58c9-e571-fd30-0ce4f6f09c70@samba.org/

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Stefan Metzmacher <metze@samba.org>
Fixes: 231264d692 ("Fix: tracepoint: static call function vs data state mismatch")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-03 10:09:30 +02:00
..
bpf bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper 2021-09-03 10:09:21 +02:00
cgroup cgroup1: fix leaked context root causing sporadic NULL deref in LTP 2021-07-31 08:16:11 +02:00
configs
debug kgdb: fix to kill breakpoints on initmem after boot 2021-03-04 11:38:46 +01:00
dma dma-mapping: handle vmalloc addresses in dma_common_{mmap,get_sgtable} 2021-07-28 14:35:38 +02:00
entry x86/entry: Move nmi entry/exit into common code 2021-03-17 17:06:36 +01:00
events perf: Fix data race between pin_count increment/decrement 2021-06-16 12:01:45 +02:00
gcov gcov: re-fix clang-11+ support 2021-04-14 08:41:58 +02:00
irq genirq/timings: Prevent potential array overflow in __irq_timings_store() 2021-08-18 08:59:15 +02:00
kcsan kcsan: Fix debugfs initcall return type 2021-05-26 12:06:54 +02:00
livepatch kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
locking lockdep: Fix wait-type for empty stack 2021-07-14 16:56:10 +02:00
power PM: EM: postpone creating the debugfs dir till fs_initcall 2021-03-30 14:32:04 +02:00
printk printk: fix deadlock when kernel panic 2021-03-04 11:38:41 +01:00
rcu srcu: Provide polling interfaces for Tiny SRCU grace periods 2021-09-03 10:09:30 +02:00
sched sched/rt: Fix double enqueue caused by rt_effective_prio 2021-08-12 13:22:19 +02:00
time timers: Move clearing of base::timer_running under base:: Lock 2021-08-12 13:22:15 +02:00
trace tracing / histogram: Fix NULL pointer dereference on strcmp() on NULL event name 2021-08-26 08:35:54 -04:00
.gitignore kbuild: update config_data.gz only when the content of .config is changed 2021-05-11 14:47:37 +02:00
acct.c kernel: acct.c: fix some kernel-doc nits 2020-10-16 11:11:19 -07:00
async.c
audit_fsnotify.c fsnotify: generalize handle_inode_event() 2020-12-30 11:54:18 +01:00
audit_tree.c fsnotify: generalize handle_inode_event() 2020-12-30 11:54:18 +01:00
audit_watch.c fsnotify: generalize handle_inode_event() 2020-12-30 11:54:18 +01:00
audit.c audit: Remove redundant null check 2020-08-26 09:10:39 -04:00
audit.h audit: change unnecessary globals into statics 2020-08-17 20:26:58 -04:00
auditfilter.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
auditsc.c audit/stable-5.9 PR 20200803 2020-08-04 14:20:26 -07:00
backtracetest.c treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD() 2020-07-30 11:15:58 -07:00
bounds.c
capability.c LSM: Signal to SafeSetID when setting group IDs 2020-10-13 09:17:34 -07:00
compat.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
configs.c
context_tracking.c
cpu_pm.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
cpu.c cpu/hotplug: Cure the cpusets trainwreck 2021-07-19 09:44:59 +02:00
crash_core.c crash_core, vmcoreinfo: append 'SECTION_SIZE_BITS' to vmcoreinfo 2021-06-23 14:42:52 +02:00
crash_dump.c
cred.c ucounts: Increase ucounts reference counter before the security hook 2021-09-03 10:09:24 +02:00
delayacct.c
dma.c
exec_domain.c
exit.c kernel/io_uring: cancel io_uring before task works 2021-01-30 13:55:18 +01:00
extable.c
fail_function.c fail_function: Remove a redundant mutex unlock 2020-11-19 11:58:16 -08:00
fork.c sched/core: Initialize the idle task with preemption disabled 2021-07-14 16:55:50 +02:00
freezer.c Revert "kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing" 2021-04-07 15:00:14 +02:00
futex.c mm, futex: fix shared futex pgoff on shmem huge page 2021-06-30 08:47:29 -04:00
gen_kheaders.sh
groups.c LSM: Signal to SafeSetID when setting group IDs 2020-10-13 09:17:34 -07:00
hung_task.c kernel/hung_task.c: make type annotations consistent 2020-11-02 12:14:19 -08:00
iomem.c
irq_work.c
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-20 16:05:58 +02:00
kallsyms.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
kcmp.c exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:46:24 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: make some symbols static 2020-08-12 10:58:02 -07:00
kexec_core.c kernel: kexec: remove the lock operation of system_transition_mutex 2021-02-03 23:28:37 +01:00
kexec_elf.c
kexec_file.c kernel: kexec_file: fix error return code of kexec_calculate_store_digests() 2021-05-19 10:13:09 +02:00
kexec_internal.h
kexec.c LSM: Introduce kernel_post_load_data() hook 2020-10-05 13:37:03 +02:00
kheaders.c
kmod.c kmod: remove redundant "be an" in the comment 2020-08-12 10:58:01 -07:00
kprobes.c kprobes: Fix to delay the kprobes jump optimization 2021-03-04 11:38:35 +01:00
ksysfs.c
kthread.c kthread_worker: fix return value when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync() 2021-07-14 16:56:02 +02:00
latencytop.c
Makefile kbuild: update config_data.gz only when the content of .config is changed 2021-05-11 14:47:37 +02:00
module_signature.c module: harden ELF info handling 2021-03-25 09:04:11 +01:00
module_signing.c module: harden ELF info handling 2021-03-25 09:04:11 +01:00
module-internal.h
module.c module: limit enabling module.sig_enforce 2021-06-30 08:47:15 -04:00
notifier.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
nsproxy.c
padata.c padata: fix possible padata_works_lock deadlock 2020-09-04 17:51:55 +10:00
panic.c panic: don't dump stack twice on warn 2020-11-14 11:26:04 -08:00
params.c params: Replace zero-length array with flexible-array member 2020-10-29 17:22:59 -05:00
pid_namespace.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
pid.c exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:46:24 +01:00
profile.c
ptrace.c ptrace: make ptrace() fail if the tracee changed its pid unexpectedly 2021-05-26 12:06:49 +02:00
range.c kernel.h: split out min()/max() et al. helpers 2020-10-16 11:11:19 -07:00
reboot.c reboot: fix overflow parsing reboot cpu number 2020-11-14 11:26:03 -08:00
regset.c regset: kill ->get() 2020-07-27 14:31:12 -04:00
relay.c kernel/relay.c: drop unneeded initialization 2020-10-16 11:11:22 -07:00
resource.c kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources 2021-05-19 10:13:09 +02:00
rseq.c
scftorture.c scftorture: Add cond_resched() to test loop 2020-08-24 18:38:38 -07:00
scs.c mm: memcontrol: account kernel stack per node 2020-08-07 11:33:25 -07:00
seccomp.c seccomp: Fix setting loaded filter count during TSYNC 2021-08-18 08:59:06 +02:00
signal.c ptrace: fix task_join_group_stop() for the case when current is traced 2020-11-02 12:14:19 -08:00
smp.c smp: Fix smp_call_function_single_async prototype 2021-05-14 09:50:46 +02:00
smpboot.c sched/core: Initialize the idle task with preemption disabled 2021-07-14 16:55:50 +02:00
smpboot.h
softirq.c softirq: Add debug check to __raise_softirq_irqoff() 2020-09-16 15:18:56 +02:00
stackleak.c stackleak: let stack_erasing_sysctl take a kernel pointer buffer 2020-09-19 13:13:39 -07:00
stacktrace.c stacktrace: Remove reliable argument from arch_stack_walk() callback 2020-09-18 14:24:16 +01:00
static_call.c static_call: Fix static_call_text_reserved() vs __init 2021-07-20 16:05:58 +02:00
stop_machine.c stop_machine, rcu: Mark functions as notrace 2020-10-26 12:12:27 +01:00
sys_ni.c mm/madvise: introduce process_madvise() syscall: an external memory hinting API 2020-10-18 09:27:10 -07:00
sys.c Add a reference to ucounts for each cred 2021-07-14 16:55:48 +02:00
sysctl-test.c
sysctl.c sysctl.c: fix underflow value setting risk in vm_table 2021-03-17 17:06:25 +01:00
task_work.c task_work: cleanup notification modes 2020-10-17 15:05:30 -06:00
taskstats.c taskstats: move specifying netlink policy back to ops 2020-10-02 19:11:12 -07:00
test_kprobes.c
torture.c
tracepoint.c tracepoint: Use rcu get state and cond sync for static call updates 2021-09-03 10:09:30 +02:00
tsacct.c
ucount.c Add a reference to ucounts for each cred 2021-07-14 16:55:48 +02:00
uid16.c
uid16.h
umh.c usermodehelper: reset umask to default before executing user process 2020-10-06 10:31:52 -07:00
up.c smp: Fix smp_call_function_single_async prototype 2021-05-14 09:50:46 +02:00
user_namespace.c Add a reference to ucounts for each cred 2021-07-14 16:55:48 +02:00
user-return-notifier.c
user.c
usermode_driver.c bpf: Fix umd memory leak in copy_process() 2021-03-30 14:32:03 +02:00
utsname_sysctl.c
utsname.c
watch_queue.c watch_queue: Limit the number of watches a user can hold 2020-08-17 09:39:18 -07:00
watchdog_hld.c
watchdog.c watchdog: fix barriers when printing backtraces from all CPUs 2021-05-19 10:13:00 +02:00
workqueue_internal.h
workqueue.c workqueue: fix UAF in pwq_unbound_release_workfn() 2021-07-31 08:16:11 +02:00