Messages in this thread |  | | | Date | Mon, 08 May 2006 09:02:06 -0700 | | From | "Martin J. Bligh" <> | | Subject | Re: High load average on disk I/O on 2.6.17-rc3 |
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Erik Mouw wrote: > On Mon, May 08, 2006 at 05:31:29PM +0200, Arjan van de Ven wrote: > >>On Mon, 2006-05-08 at 17:22 +0200, Erik Mouw wrote: >> >>>... except that any kernel < 2.6 didn't account tasks waiting for disk >>>IO. >> >>they did. It was "D" state, which counted into load average. > > > They did not or at least to a much lesser extent. That's the reason why > ZenIV.linux.org.uk had a mail DoS during the last FC release and why we > see load average questions on lkml. > > I've seen it on our servers as well: when using 2.4 and doing 50 MB/s > to disk (through NFS), the load just was slightly above 0. When we > switched the servers to 2.6 it went to ~16 for the same disk usage.
Looks like both count it, or something stranger is going on.
2.6.16:
static unsigned long count_active_tasks(void) { return (nr_running() + nr_uninterruptible()) * FIXED_1; } 2.4.0:
static unsigned long count_active_tasks(void) { struct task_struct *p; unsigned long nr = 0; read_lock(&tasklist_lock); for_each_task(p) { if ((p->state == TASK_RUNNING || (p->state & TASK_UNINTERRUPTIBLE))) nr += FIXED_1; } read_unlock(&tasklist_lock); return nr; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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