On Sat, Aug 1, 2009 at 10:53 PM, Huan Ren <hu...@google.com> wrote:
>
> - The crash rates on chromebot are comparable for builds with and
> without tcmalloc. The crash rate for tcmalloc build is higher but it
> seems within error margin.
> - Wtih tcmalloc disabled, there are some promising data from Purify
> test run and ChromeBot run with full page heap enabled. These are
> still under further investigation.
BTW, all the server guys have tcmalloc heap profiling enabled by default;
they can pinpoint leaks at process exit by default on their servers (when I
saw the tool recently, I was very impressed!) Jim and Will investigated
with CraigS - turns out that this portion of tcmalloc isn't in the
public-domain version of tcmalloc which we use.
If we help Craig get this part of tcmalloc open sourced, we can get much of
purify in 'by default'.
>
> - The performance results are same as last time we compared. With
> tcmalloc, the most perf gain is from page-cycler-moz: 15% improvement
> (with 25% more memory usage). The perfor gain on page-cycler-more-js
> is 4%, as we see tcmalloc has no perf impact on V8 benchmark. The
> performance gain on DOM is significant: from score 325 to 414.
I thought it was also interesting to look at the tcmalloc benefits on XP vs
Vista (we had observed this before too). It's clear that Microsoft
substantially improved the heap on Vista - while the gains on XP were 8-9%
for the intl page cyclers on XP, the gains were only 1-2% on Vista.
Similarly for the DOM and other tests, Vista gains for tcmalloc are always
substantially less than on XP.
We might want to look more closely at Win7; I don't think the heap changed
much from Vista to Win7, but maybe eventually tcmalloc won't be interesting.
Or - if we can reduce webkit heap usage, maybe we can make it so that
tcmalloc on vista doesn't improve anything.
Mike
>
>
> r22251 re-enables tcmalloc on trunk. We can merge 22080 to dev branch if
> needed.
>
> Huan
>
> On Fri, Jul 31, 2009 at 6:51 PM, cpu<c...@chromium.org> wrote:
> >
> > What are the results of this experiment?
> >
> > On Jul 30, 12:15 pm, Huan Ren <hu...@chromium.org> wrote:
> >> I just submitted a change (22080) that disables tcmalloc used on
> >> Windows platform. The plan is keeping it in trunk for 24 hours and
> >> then reverting it. The intentions are
> >> - Having another round of performance comparison between build with
> >> and w/o tcmalloc.
> >> - Having a full run of UI test under purify with tcmalloc disabled.
> >> - Getting a verified CL in case we'd like to build an alternative
> >> dev build w/o tcmalloc for A/B test.
> >>
> >> As a head up, the performance, stability, and purify test results
> >> could be different during the period.
> >>
> >> Huan
> > >
> >
>
> >
>
--~--~---------~--~----~------------~-------~--~----~
Chromium Developers mailing list: chromium-dev@googlegroups.com
View archives, change email options, or unsubscribe:
http://groups.google.com/group/chromium-dev
-~----------~----~----~----~------~----~------~--~---
