The following commit has been merged into the sched/core branch of tip: Commit-ID: dbe9337109c2705f08e6a00392f991eb2d2570a5 Gitweb: https://git.kernel.org/tip/dbe9337109c2705f08e6a00392f991eb2d2570a5 Author: Muchun Song <songmuchun@xxxxxxxxxxxxx> AuthorDate: Mon, 20 Apr 2020 15:04:53 +08:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Tue, 19 May 2020 20:34:14 +02:00 sched/cpuacct: Fix charge cpuacct.usage_sys The user_mode(task_pt_regs(tsk)) always return true for user thread, and false for kernel thread. So it means that the cpuacct.usage_sys is the time that kernel thread uses not the time that thread uses in the kernel mode. We can try get_irq_regs() first, if it is NULL, then we can fall back to task_pt_regs(). Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20200420070453.76815-1-songmuchun@xxxxxxxxxxxxx --- kernel/sched/cpuacct.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index 6448b04..941c28c 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -5,6 +5,7 @@ * Based on the work by Paul Menage (menage@xxxxxxxxxx) and Balbir Singh * (balbir@xxxxxxxxxx). */ +#include <asm/irq_regs.h> #include "sched.h" /* Time spent by the tasks of the CPU accounting group executing in ... */ @@ -339,7 +340,7 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime) { struct cpuacct *ca; int index = CPUACCT_STAT_SYSTEM; - struct pt_regs *regs = task_pt_regs(tsk); + struct pt_regs *regs = get_irq_regs() ? : task_pt_regs(tsk); if (regs && user_mode(regs)) index = CPUACCT_STAT_USER;