Re: 2.6.1 slower than 2.4, smp/scsi/sw-raid/reiserfs

[Nick Piggin]

Philip Martin wrote:

> Nick Piggin <piggin@xxxxxxxxxxxxxxx> writes:
>
>  
>
> > Philip Martin wrote:
> >
> >    
> >
> > > Nick Piggin <piggin@xxxxxxxxxxxxxxx> writes:
> > >      
> > >
> > > > When the build finishes and there is no other activity, can you
> > > > try applying anonymous memory pressure until it starts swapping
> > > > to see if everything gets reclaimed properly?
> > > >        
> > > How do I apply anonymous memory pressure?
> > >      
> > Well just run something that uses a lot of memory and doesn't
> > do much else. Run a few of these if you like:
> >
> > #include <stdlib.h>
> > #include <unistd.h>
> > #define MEMSZ (64 * 1024 * 1024)
> > int main(void)
> > {
> >    int i;
> >    char *mem = malloc(MEMSZ);
> >    for (i = 0; i < MEMSZ; i+=4096)
> >       mem[i] = i;
> >    sleep(60);
> >    return 0;
> > }
> >    
>
> This is what free reports after the build
>
>             total       used       free     shared    buffers     cached
> Mem:        516396     215328     301068          0      85084      68364
> -/+ buffers/cache:      61880     454516
> Swap:      1156664      40280    1116384
>
> then after starting 10 instances of the above program
>
>             total       used       free     shared    buffers     cached
> Mem:        516396     513028       3368          0        596       5544
> -/+ buffers/cache:     506888       9508
> Swap:      1156664     320592     836072
>
> and then after those programs finish
>
>             total       used       free     shared    buffers     cached
> Mem:        516396      35848     480548          0        964       5720
> -/+ buffers/cache:      29164     487232
> Swap:      1156664      54356    1102308
>
> It looks OK to me.
>
>  

Yeah thats looks fine. It was a wild guess.

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