Re: LatencyTOP infrastructure patch

From: Arjan van de Ven
Date: Mon Jan 21 2008 - 11:18:08 EST


KOSAKI Motohiro wrote:
Hi

+static void __sched
+account_global_scheduler_latency(struct task_struct *tsk, int usecs)
+{
+ int i;
+ int firstnonnull = MAXLR + 1;
+
+ if (!tsk->latency_reason.reason)
+ return;
+
+ /* skip kernel threads for now */
+ if (!tsk->mm)
+ return;

Why do you ignore kernel thread?

may be, some network filesystem use kernel thread for local I/O.
What do you think it?

kernel threads (by themselves) don't tend to result in user visible latency...
at least that's my assumption so far... if you think I'm wrong... I'm open to be shown
that we should count them.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/