Messages in this thread | | | Date | Fri, 29 May 2015 10:04:25 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] proc/schedstat: Expose /proc/<pid>/schedstat if delay accounting is enabled |
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* Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> wrote:
> /proc/<pid>/schedstat is currently only available if CONFIG_SCHEDSTATS is > enabled. But, all the fields that this exposes are available and valid > if CONFIG_TASK_DELAY_ACCT is enabled as well. > > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > --- > fs/proc/base.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/fs/proc/base.c b/fs/proc/base.c > index 093ca14..3ece303 100644 > --- a/fs/proc/base.c > +++ b/fs/proc/base.c > @@ -304,14 +304,17 @@ static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns, > } > #endif > > +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) > +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) > +#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
So such #ifdef parades are ugly and are usually a sign of some problem with the patch - as in this case.
But there's deeper problems as well:
/* * Provides /proc/PID/schedstat */ static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { seq_printf(m, "%llu %llu %lu\n", (unsigned long long)task->se.sum_exec_runtime, (unsigned long long)task->sched_info.run_delay, task->sched_info.pcount);
return 0; }
- The sum_exec_runtime field is available unconditionally.
- But the sched_info.run_delay field is only maintained if CONFIG_SCHEDSTATS is enabled.
- Also, the sched_info.pcount field is again only maintained if CONFIG_SCHEDSTATS is enabled.
So the claim in your changelog that these fields are maintained in the delayaccounting case is plain false: none of the fields are conditional on delay accounting.
So what's the purpose of your patch?
Thanks,
Ingo
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