Re: horrible disk thorughput on itanium

Mike Galbraith (mikeg@wen-online.de)
Fri, 7 Dec 2001 07:11:29 +0100 (CET)


On 6 Dec 2001, Andi Kleen wrote:

> Andrew Morton <akpm@zip.com.au> writes:
> >
> > 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.
>
> The usual difference is if you have a pthreads capable C library
> or not. For newer glibc bonnie++ should definitely use
> putc_unlocked(); otherwise it'll eat lock overhead for each character
> to take the FILE lock.
>
> As far as I can see bonnie++ doesn't use putc_unlocked, but putc.

Plain old Bonnie suffered from the same thing. I long ago made it
use putc_unlocked() here because throughput was horrible otherwise.

-Mike

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