sched/cpuacct: Fix charge percpu cpuusage
authorChengming Zhou <zhouchengming@bytedance.com>
Sun, 20 Feb 2022 05:14:24 +0000 (13:14 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 8 Apr 2022 12:23:11 +0000 (14:23 +0200)
commitb7aec0843e2883b4bd5bed46f70b0febb046f9cc
tree858668f8ae84d669ee10f769267645c3aca4962f
parentcc91880f041705062aab4cc1d4e1271f4ecabd08
sched/cpuacct: Fix charge percpu cpuusage

[ Upstream commit 248cc9993d1cc12b8e9ed716cc3fc09f6c3517dd ]

The cpuacct_account_field() is always called by the current task
itself, so it's ok to use __this_cpu_add() to charge the tick time.

But cpuacct_charge() maybe called by update_curr() in load_balance()
on a random CPU, different from the CPU on which the task is running.
So __this_cpu_add() will charge that cputime to a random incorrect CPU.

Fixes: 73e6aafd9ea8 ("sched/cpuacct: Simplify the cpuacct code")
Reported-by: Minye Zhu <zhuminye@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220220051426.5274-1-zhouchengming@bytedance.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
kernel/sched/cpuacct.c