Re: horrible disk thorughput on itanium

[Padraig Brady]

Andi Kleen wrote:

> [e-mail] (Linus Torvalds) writes:
> 
>>"putc()" is a standard function.  If it sucks, let's get it fixed.  And
>>instead of changing bonnie, how about pinging the _real_ people who
>>write sucky code?
>>
> 
> It is easy to fix. Just do #define putc putc_unlocked
> There is just a slight problem: it'll fail if your application is threaded
> and wants to use the same FILE from multiple threads.
> 
> It is a common problem on all OS that eventually got threadsafe stdio. 
> I bet putc sucks on Solaris too.
> 
> -Andi

Interesting thread on this:
http://sources.redhat.com/ml/bug-glibc/2001-11/msg00079.html

for glibc 2.2.4 with the following program with input file
of 354371 lines of text(/usr/share/doc/*), where the average line
length was 37 chars.

getc/putc
real 
2.181s
user 
2.150s
sys 
0.030s
getc_unlocked/putc_unlocked
real 
0.326s
user 
0.280s
sys 
0.040s

I.E. 669% faster!

Padraig.

-------------------
#include <stdio.h>

#ifndef  _REENTRANT
#    undef getc
#    define getc(x)   getc_unlocked(x)
#    undef putc
#    define putc(x,y) putc_unlocked(x,y)
#endif //_REENTRANT

void main(void)
{
     int c;
     while((c=getc(stdin))!=EOF) putc(c,stdout);
}