[linux-mm-cc] Announce: ccache release 0.1

[John McCabe-Dansted]

On Tue, Feb 19, 2008 at 11:04 PM, Nitin Gupta <nitingupta910 at gmail.com> wrote:
>  > > > BTW, why is the default 10% of mem?
>  >
>  > Perhaps 100% (or maybe 50%) would be a more sensible default? For me
>  > 66% makes a huge difference to the Hardy liveCD performance. 10% makes
>  > a difference but 50%+ goes from "ls /" taking 10s to snappy
>  > performance even on large applications like Firefox.
>  >
>
>  I think this depends a lot on kind of workload and system. For e.g:
>  - On desktops, retaining too many anonymous pages at cost of
>  continuously losing page-cache (filesystem-backed) pages can hurt
>  performance for workload that repeatedly access same file(s).
>  - On embedded systems, too much de/compression will drain all battery.
>  and so on...

I was thinking that for the LiveCD case the primary performance hit
would be seeking on the CD drive. Hence to maximize memory available
for caching the CD, we should
   1) Use 100% mem for compcache.
   2) Set compcaches priority to be low, so that hdd swap will be used
first if it exists.
Does this seem reasonable?

>  Unfortunately none of these messages suggest why crash happened.
>  If you can send entire log, that will probably be more useful.

I now tested this with QEMU and -smp 2. Still cannot reproduce the
bug. QEMU doesn't seem to use both host CPUs so I presume it doesn't
interleave instructions nearly as much as real SMP would.

I'll test this some more on my real hardware (crosses fingers)


-- 
John C. McCabe-Dansted
PhD Student
University of Western Australia