Messages in this thread | | | Date | Thu, 16 Apr 2020 12:01:32 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] sched/cpuacct: Fix charge cpuacct.usage_sys incorrently. |
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On Thu, 16 Apr 2020 11:35:02 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> On Thu, 16 Apr 2020 22:18:33 +0800 > Muchun Song <songmuchun@bytedance.com> wrote: > > > 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 > > use get_irq_regs() instead of task_pt_regs() to fix it. > > > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> > > --- > > 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 6448b0438ffb2..edfc62554648e 100644 > > --- a/kernel/sched/cpuacct.c > > +++ b/kernel/sched/cpuacct.c > > @@ -5,6 +5,7 @@ > > * Based on the work by Paul Menage (menage@google.com) and Balbir Singh > > * (balbir@in.ibm.com). > > */ > > +#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(); > > But get_irq_regs() is only available from interrupt context. This will be > NULL most the time, whereas the original way will have regs existing for > the task.
Perhaps you want:
regs = get_irqs_regs(); if (!regs) regs = task_pt_regs(tsk);
?
-- Steve
> > > > > if (regs && user_mode(regs)) > > index = CPUACCT_STAT_USER; >
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