Message-ID: <3C0FD955.4510B738@zip.com.au>
Date: Thu, 06 Dec 2001 12:47:17 -0800
From: Andrew Morton <akpm@zip.com.au>
MIME-Version: 1.0
To: Greg Hennessy <gsh@cox.rr.com>
CC: linux-kernel@vger.kernel.org
Subject: Re: horrible disk thorughput on itanium
In-Reply-To: <20011206110713.A8404@cox.rr.com>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org

Greg Hennessy wrote:
> 
> ...
> Hydra is the itanium, leo is the 32 bit machine. The character io of
> hydra is a factor of 10 slower than that of leo. Is this more likely a
> kernel issue, or a glibc issue? Both machiness run standard redhat
> 7.1, and 2.4.9-12smp kernels.
> 

The character I/O part of bonnie++ writes a single character at a time,
via stdio.  It's more a test of your C library than of the kernel.

The fact that you get the same throughput on each platform with
the block I/O part of the test indicates that the hardware and
kernel are OK, but the C library is broken.

Not sure how to diagnose this.  Probably you should write a
simple five-line stdio-based test program, see if that exhibits
the same behaviour, then fiddle with setvbuf().

-
-
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/