In function __account_forceidle_time(), task_group_account_field()
is called to update kernel_cpustat.cpustat[CPUTIME_FORCEIDLE].
However, p may be not running on current cpu, so update cpustat with
this_cpu_add() is incorrect.
To fix this problem, we get the cpu of p first, and then add delta
to kcpustat_cpu(cpu).cpustat[CPUTIME_FORCEIDLE].
Fixes: 1fcf54deb767 ("sched/core: add forced idle accounting for cgroups")
Signed-off-by: Cruz Zhao <[email protected]>
---
kernel/sched/cputime.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index af7952f12e6c..6f18fdc4a0dc 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -239,9 +239,12 @@ void account_idle_time(u64 cputime)
*/
void __account_forceidle_time(struct task_struct *p, u64 delta)
{
+ unsigned int cpu = task_cpu(p);
+
__schedstat_add(p->stats.core_forceidle_sum, delta);
- task_group_account_field(p, CPUTIME_FORCEIDLE, delta);
+ kcpustat_cpu(cpu).cpustat[CPUTIME_FORCEIDLE] += delta;
+ cgroup_account_cputime_field(p, index, tmp);
}
#endif
--
2.39.3
Hi Cruz,
kernel test robot noticed the following build errors:
[auto build test ERROR on tip/sched/core]
[also build test ERROR on linus/master v6.7-rc1 next-20231117]
[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/Cruz-Zhao/sched-core-fix-incorrect-cpustat-CPUTIME_FORCEIDLE-update/20231117-205845
base: tip/sched/core
patch link: https://lore.kernel.org/r/20231117125624.16745-1-CruzZhao%40linux.alibaba.com
patch subject: [PATCH] sched/core: fix incorrect cpustat[CPUTIME_FORCEIDLE] update
config: x86_64-buildonly-randconfig-004-20231118 (https://download.01.org/0day-ci/archive/20231118/[email protected]/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231118/[email protected]/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 <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
All errors (new ones prefixed by >>):
In file included from kernel/sched/build_policy.c:52:
kernel/sched/cputime.c: In function '__account_forceidle_time':
>> kernel/sched/cputime.c:247:41: error: 'index' undeclared (first use in this function)
247 | cgroup_account_cputime_field(p, index, tmp);
| ^~~~~
kernel/sched/cputime.c:247:41: note: each undeclared identifier is reported only once for each function it appears in
>> kernel/sched/cputime.c:247:48: error: 'tmp' undeclared (first use in this function); did you mean 'tms'?
247 | cgroup_account_cputime_field(p, index, tmp);
| ^~~
| tms
vim +/index +247 kernel/sched/cputime.c
232
233
234 #ifdef CONFIG_SCHED_CORE
235 /*
236 * Account for forceidle time due to core scheduling.
237 *
238 * REQUIRES: schedstat is enabled.
239 */
240 void __account_forceidle_time(struct task_struct *p, u64 delta)
241 {
242 unsigned int cpu = task_cpu(p);
243
244 __schedstat_add(p->stats.core_forceidle_sum, delta);
245
246 kcpustat_cpu(cpu).cpustat[CPUTIME_FORCEIDLE] += delta;
> 247 cgroup_account_cputime_field(p, index, tmp);
248 }
249 #endif
250
--
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https://github.com/intel/lkp-tests/wiki