Re: horrible disk thorughput on itanium

Padraig Brady (padraig@antefacto.com)
Fri, 07 Dec 2001 21:00:20 +0000


David S. Miller wrote:

> From: Andi Kleen <ak@suse.de>
> Date: 07 Dec 2001 14:54:49 +0100
>
> It is a common problem on all OS that eventually got threadsafe stdio.
> I bet putc sucks on Solaris too.
>
> Nope, they even inline the full implementation it in their header
> files so they beat even our putc_unlocked() to the point it is
> embarassing.

glibc does this also?
from /usr/include/libio.h

#define _IO_putc_unlocked(_ch, _fp) \
(((_fp)->_IO_write_ptr >= (_fp)->_IO_write_end) \
? __overflow (_fp, (unsigned char) (_ch)) \
: (unsigned char) (*(_fp)->_IO_write_ptr++ = (_ch)))

I'm just thinking however that apps compiled with the
above will break with Linus' suggestion of using locks
only after a pthread_create(), as they don't really
call the library in the above case at all.

Padraig.

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