Re: Fw: [Bug 4520] New: /proc/*/maps fragments too quickly compared to

Wolfgang Wander
2005-05-10T19:50:13Z

Andrew Morton writes:
> "Chen, Kenneth W" <kenneth.w.chen@intel.com> wrote:
> >
> > Andrew Morton wrote Tuesday, May 10, 2005 11:58 AM
> > > "Chen, Kenneth W" <kenneth.w.chen@intel.com> wrote:
> > > > Andrew Morton wrote on Monday, May 09, 2005 2:27 PM
> > > > > Possibly for the 2.6.12 release the safest approach would be to just
> > > > > disable the free area cache while we think about it.
> > > >
> > > > I hope people are not thinking permanently kill the free area cache
> > > > algorithm. It is known to give a large percentage of performance gain
> > > > on specweb SSL benchmark. I think it gives 4-5% gain from free area
> > > > cache algorithm.
> > >
> > > It also makes previously-working workloads completely *fail*.
> >
> > I agree that functionality over rule most of everything else. Though, I
> > do want to bring to your attention on how much performance regression we
> > will see if the free area cache is completely disabled. I rather make
> > noise now instead of a couple month down the road :-)
>
> Well we allegedly have a patch from Wolfgang which fixes things up, but our
> talk-to-testing ratio seems to be infinite.
>
> This is pretty serious, guys. Could someone please find the time to work
> on it?

I volunteer to do the testing - just the test I got from Ingo did
not show any timing difference for either of the three solutions:

a) use free_cache
b) disable free_cache
c) use my maybe improved and maybe much too complex free_cache

The test_str02.c I got only ran up to 1300 threads on my machine (8GB
dual x86_64) and Ingo expected it to go up to 20000.

If there is any other test case I'm very willing to do the timing
tests...

Wolfgang