[linux-mm-cc] kernel make benchmark on small x86 desktop

[Nitin Gupta]

On Mon, Apr 14, 2008 at 12:08 PM, Nai Xia <nai.xia at gmail.com> wrote:
> Hi, Nitin,
>
>  Unfortunately, this result is negative.
>
>  I limited the RAM memory to 56M, after that the kernel compling test was done:
>
>  # time make -j4 bzImage >/dev/null 2>&1
>
>  the result without compcache:
>  real    125m57.405s
>  user    19m28.617s
>  sys     2m41.942s
>
>  the result with default loaded compcache:
>  real    153m35.538s
>  user    19m45.838s
>  sys     4m2.727s
>
>
>  I personally think this give us the information when some "stale"
>  anonymous pages get "pinned" in memory for a long time, it is bad  for
>  overal performance.
>  This will never happen in fillmem benchmark, because it travels the
>  memory back and forth,
>  the possibility of visiting each page is equal.
>
>  How do you think ?


kernel compile is page-cache intensive workload, and we only compress
swap-cache.
So, I think in all such benchmarks which are page-cache intensive will
have negative results.

Ideally compcache should be smart itself to "shut itself off" in such cases :)

- Nitin