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

[Nick Piggin <piggin@cyberone.com.au>]

Philip Martin wrote:

>Nick Piggin <piggin@cyberone.com.au> writes:
>
>  
>
>>Philip Martin wrote:
>>
>>    
>>
>>>Nick Piggin <piggin@cyberone.com.au> 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.