Re: horrible disk thorughput on itanium

Andrew Morton
2001-12-06T20:50:16Z

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().

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