From: Andrew Morton <akpm@digeo.com>
To: Badari Pulavarty <pbadari@us.ibm.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: More Testing with 4000 disks
Date: Mon, 7 Apr 2003 14:15:51 -0700 [thread overview]
Message-ID: <20030407141551.5900e44f.akpm@digeo.com> (raw)
In-Reply-To: <200304071454.49849.pbadari@us.ibm.com>
Badari Pulavarty <pbadari@us.ibm.com> wrote:
>
> Hi,
>
> Here is more on testing with simulated 4000 disks.
>
> I mounted 4000 simulated (scsi_debug) disks. But
> when I tried to do IO on 200 of them (just reads),
> system is 100% busy. Here are the vmstat,
> 10-sec profile output and sysrq-t output.
>
> I am wondering why 100% sys ?
>
This doesn't make sense. You're showing 50% CPU time in schedule(), yet the
(undescribed) machine is doing only 11k context switches/sec.
How come?
What context switch rate and profile were you getting when performing IO against a
large number of real disks?
next prev parent reply other threads:[~2003-04-07 22:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-07 21:54 Badari Pulavarty
2003-04-07 21:15 ` Andrew Morton [this message]
2003-04-07 22:32 ` Badari Pulavarty
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