Re: Want to allocate almost all the memory with no swap

Simon Derr
2001-04-19T16:56:16Z

On Thu, 19 Apr 2001, Simon Derr wrote:

> If I ask much less memory it works.. but has no interest.
>
> In fact I a call mlockall() _before_ doing my big malloc, it works even
> when I ask 240 megs, but:
> -Under 2.2.17, quickly the kernel kills my process
> -Under 2.4.2, kswapd again eats the CPU:
>
> Mem: 254692K av, 252868K used, 1824K free, 0K shrd, 88K buff
> Swap: 313256K av, 5476K used, 307780K free 4204K cached
>
> PID USER PRI NI SIZE RSS SHARE STAT LIB %CPU %MEM TIME COMMAND
> 3 root 14 0 0 0 0 RW 0 47.4 0.0 20:50 kswapd
> 1277 root 14 0 241M 241M 968 R 0 46.8 96.8 0:12 loop
> 5 root 9 0 0 0 0 SW 0 5.3 0.0 0:23 bdflush
> 1278 root 10 0 468 404 404 R 0 0.3 0.1 0:00 top
>

Actually this is what happens under 2.4.2 :
when I launch the program, during about one minute kswapd eats 50% cpu,
and bdflush takes 2-5% cpu,
One minute later approx, they both stop eating the cpu and my process gets
almost 100% of the cpu (a PIII 733).

The same happens if I kill and launch my program a second time.

Sorry for the pollution I bring to your mailing list...