From: kernel test robot <lkp@intel.com>
To: Namhyung Kim <namhyung@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>
Cc: oe-kbuild-all@lists.linux.dev,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Rosalie Fang <rosaliefang@google.com>
Subject: Re: [PATCH] perf/core: Fix slow perf_event_task_exit() with LBR callstacks
Date: Tue, 13 Jan 2026 22:58:00 +0800 [thread overview]
Message-ID: <202601132200.HPQCccpc-lkp@intel.com> (raw)
In-Reply-To: <20260112165157.1919624-1-namhyung@kernel.org>
Hi Namhyung,
kernel test robot noticed the following build warnings:
[auto build test WARNING on perf-tools-next/perf-tools-next]
[also build test WARNING on tip/perf/core perf-tools/perf-tools linus/master v6.19-rc5 next-20260113]
[cannot apply to acme/perf/core]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Namhyung-Kim/perf-core-Fix-slow-perf_event_task_exit-with-LBR-callstacks/20260113-005301
base: https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git perf-tools-next
patch link: https://lore.kernel.org/r/20260112165157.1919624-1-namhyung%40kernel.org
patch subject: [PATCH] perf/core: Fix slow perf_event_task_exit() with LBR callstacks
config: riscv-randconfig-r111-20260113 (https://download.01.org/0day-ci/archive/20260113/202601132200.HPQCccpc-lkp@intel.com/config)
compiler: riscv64-linux-gcc (GCC) 9.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260113/202601132200.HPQCccpc-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601132200.HPQCccpc-lkp@intel.com/
sparse warnings: (new ones prefixed by >>)
kernel/events/core.c:1486:15: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:1486:15: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:1486:15: sparse: struct perf_event_context *
kernel/events/core.c:1499:28: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:1499:28: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:1499:28: sparse: struct perf_event_context *
kernel/events/core.c:3669:20: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:3669:20: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:3669:20: sparse: struct perf_event_context *
kernel/events/core.c:3673:18: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:3673:18: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:3673:18: sparse: struct perf_event_context *
kernel/events/core.c:3674:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:3674:23: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:3674:23: sparse: struct perf_event_context *
kernel/events/core.c:3727:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:3727:25: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:3727:25: sparse: struct perf_event_context *
kernel/events/core.c:3728:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:3728:25: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:3728:25: sparse: struct perf_event_context *
kernel/events/core.c:4111:15: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:4111:15: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:4111:15: sparse: struct perf_event_context *
kernel/events/core.c:4519:15: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:4519:15: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:4519:15: sparse: struct perf_event_context *
kernel/events/core.c:5008:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:5008:25: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:5008:25: sparse: struct perf_event_context *
kernel/events/core.c:6651:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:6651:9: sparse: struct perf_buffer [noderef] __rcu *
kernel/events/core.c:6651:9: sparse: struct perf_buffer *
kernel/events/core.c:5283:21: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct perf_ctx_data [noderef] __rcu **___op @@ got struct perf_ctx_data **__ai_oldp @@
kernel/events/core.c:5283:21: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct perf_ctx_data [noderef] __rcu *__new @@ got struct perf_ctx_data *[assigned] cd @@
>> kernel/events/core.c:5283:21: sparse: sparse: cast removes address space '__rcu' of expression
kernel/events/core.c:5294:37: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct perf_ctx_data [noderef] __rcu **___op @@ got struct perf_ctx_data **__ai_oldp @@
kernel/events/core.c:5294:37: sparse: sparse: cast removes address space '__rcu' of expression
kernel/events/core.c:6166:24: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted __poll_t [usertype] events @@ got int @@
kernel/events/core.c:6402:22: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:6402:22: sparse: struct perf_buffer [noderef] __rcu *
kernel/events/core.c:6402:22: sparse: struct perf_buffer *
kernel/events/core.c:6526:14: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:6526:14: sparse: struct perf_buffer [noderef] __rcu *
kernel/events/core.c:6526:14: sparse: struct perf_buffer *
kernel/events/core.c:6559:14: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:6559:14: sparse: struct perf_buffer [noderef] __rcu *
kernel/events/core.c:6559:14: sparse: struct perf_buffer *
kernel/events/core.c:6672:14: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:6672:14: sparse: struct perf_buffer [noderef] __rcu *
kernel/events/core.c:6672:14: sparse: struct perf_buffer *
kernel/events/core.c:6688:14: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:6688:14: sparse: struct perf_buffer [noderef] __rcu *
kernel/events/core.c:6688:14: sparse: struct perf_buffer *
kernel/events/core.c:8667:15: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8667:15: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:8667:15: sparse: struct perf_event_context *
kernel/events/core.c:8755:13: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8755:13: sparse: struct perf_buffer [noderef] __rcu *
kernel/events/core.c:8755:13: sparse: struct perf_buffer *
kernel/events/core.c:8859:61: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct task_struct *p @@ got struct task_struct [noderef] __rcu *real_parent @@
kernel/events/core.c:8859:61: sparse: expected struct task_struct *p
kernel/events/core.c:8859:61: sparse: got struct task_struct [noderef] __rcu *real_parent
kernel/events/core.c:8861:61: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct task_struct *p @@ got struct task_struct [noderef] __rcu *real_parent @@
kernel/events/core.c:8861:61: sparse: expected struct task_struct *p
kernel/events/core.c:8861:61: sparse: got struct task_struct [noderef] __rcu *real_parent
kernel/events/core.c:9597:15: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:9597:15: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:9597:15: sparse: struct perf_event_context *
kernel/events/core.c:10792:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:10792:9: sparse: struct swevent_hlist [noderef] __rcu *
kernel/events/core.c:10792:9: sparse: struct swevent_hlist *
kernel/events/core.c:10831:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:10831:17: sparse: struct swevent_hlist [noderef] __rcu *
kernel/events/core.c:10831:17: sparse: struct swevent_hlist *
kernel/events/core.c:14213:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:14213:9: sparse: struct perf_event_context [noderef] __rcu *
kernel/events/core.c:14213:9: sparse: struct perf_event_context *
kernel/events/core.c:14733:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:14733:17: sparse: struct swevent_hlist [noderef] __rcu *
kernel/events/core.c:14733:17: sparse: struct swevent_hlist *
kernel/events/core.c:184:9: sparse: sparse: context imbalance in 'perf_ctx_lock' - wrong count at exit
kernel/events/core.c:200:9: sparse: sparse: context imbalance in 'perf_ctx_unlock' - unexpected unlock
kernel/events/core.c: note: in included file (through include/linux/rbtree.h, include/linux/mm_types.h, include/linux/mmzone.h, ...):
include/linux/rcupdate.h:897:25: sparse: sparse: context imbalance in 'perf_lock_task_context' - different lock contexts for basic block
kernel/events/core.c:1533:17: sparse: sparse: context imbalance in 'perf_pin_task_context' - unexpected unlock
kernel/events/core.c:3009:9: sparse: sparse: context imbalance in '__perf_install_in_context' - wrong count at exit
kernel/events/core.c:4982:17: sparse: sparse: context imbalance in 'find_get_context' - unexpected unlock
kernel/events/core.c: note: in included file:
kernel/events/internal.h:204:46: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected void const [noderef] __user *from @@ got void const *src @@
kernel/events/core.c:10645:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:10645:17: sparse: struct swevent_hlist [noderef] __rcu *
kernel/events/core.c:10645:17: sparse: struct swevent_hlist *
kernel/events/core.c:10665:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:10665:17: sparse: struct swevent_hlist [noderef] __rcu *
kernel/events/core.c:10665:17: sparse: struct swevent_hlist *
kernel/events/core.c:10781:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:10781:16: sparse: struct swevent_hlist [noderef] __rcu *
kernel/events/core.c:10781:16: sparse: struct swevent_hlist *
kernel/events/core.c:10781:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:10781:16: sparse: struct swevent_hlist [noderef] __rcu *
kernel/events/core.c:10781:16: sparse: struct swevent_hlist *
kernel/events/core.c:10781:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:10781:16: sparse: struct swevent_hlist [noderef] __rcu *
kernel/events/core.c:10781:16: sparse: struct swevent_hlist *
vim +/__rcu +5283 kernel/events/core.c
5271
5272 static int
5273 attach_task_ctx_data(struct task_struct *task, struct kmem_cache *ctx_cache,
5274 bool global)
5275 {
5276 struct perf_ctx_data *cd, *old = NULL;
5277
5278 cd = alloc_perf_ctx_data(ctx_cache, global);
5279 if (!cd)
5280 return -ENOMEM;
5281
5282 for (;;) {
> 5283 if (try_cmpxchg(&task->perf_ctx_data, &old, cd)) {
5284 if (old)
5285 perf_free_ctx_data_rcu(old);
5286 /*
5287 * Above try_cmpxchg() pairs with try_cmpxchg() from
5288 * detach_task_ctx_data() such that
5289 * if we race with perf_event_exit_task(), we must
5290 * observe PF_EXITING.
5291 */
5292 if (task->flags & PF_EXITING) {
5293 /* detach_task_ctx_data() may free it already */
5294 if (try_cmpxchg(&task->perf_ctx_data, &cd, NULL))
5295 perf_free_ctx_data_rcu(cd);
5296 }
5297 return 0;
5298 }
5299
5300 if (!old) {
5301 /*
5302 * After seeing a dead @old, we raced with
5303 * removal and lost, try again to install @cd.
5304 */
5305 continue;
5306 }
5307
5308 if (refcount_inc_not_zero(&old->refcount)) {
5309 free_perf_ctx_data(cd); /* unused */
5310 return 0;
5311 }
5312
5313 /*
5314 * @old is a dead object, refcount==0 is stable, try and
5315 * replace it with @cd.
5316 */
5317 }
5318 return 0;
5319 }
5320
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next prev parent reply other threads:[~2026-01-13 14:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-12 16:51 [PATCH] perf/core: Fix slow perf_event_task_exit() with LBR callstacks Namhyung Kim
2026-01-13 0:24 ` kernel test robot
2026-01-13 14:58 ` kernel test robot [this message]
2026-01-13 21:21 ` Namhyung Kim
2026-01-15 21:44 ` [tip: perf/core] " tip-bot2 for Namhyung Kim
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