horrible disk thorughput on itanium

Geoff Keating geoffk@geoffk.org
Fri Dec 7 19:52:00 GMT 2001


> Date: Fri, 07 Dec 2001 16:07:27 -0800
> From: Andrew Morton <akpm@zip.com.au>

> In answer to Geoff Keating's question, this program:
> 
> #include <stdio.h>
> 
> main()
> {
>         int i;
> 
>         for (i = 0; i < 100*1000*1000; i++)
>                 putc(0, stdout);
>         exit(0);
> }
> 
> when directed to /dev/null takes 7.5 seconds.  But only 1.3 seconds
> with putc_unlocked.

I well believe that, since putc_unlocked is a macro which can be
inlined and then further optimised, but I was referring to the
proposed change to putc(), which doesn't make it a macro and actually
adds more code.

-- 
- Geoffrey Keating <geoffk@geoffk.org> <geoffk@redhat.com>



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