[webkit-dev] Tip: Use 64-bit git binaries on Mac OS X

[Jeremy Orlow]

For what it's worth, on my 12GB of ram mac pro:

$ sudo sysctl -w kern.maxvnodes=384000
kern.maxvnodes: 197632 -> 384000

Took times from 2.11-2.06 down to 2.05-2.02.  I.e. it made a small
difference, but not much.  The 64 bit patch definitely seemed to help, but I
didn't think to time before and after.

J

On Wed, Dec 8, 2010 at 11:38 PM, Eric Seidel <eric at webkit.org> wrote:

> Mark Rowe pointed out to me over IRC that the real problem is we're
> blowing out the vnode cache.
>
> Even on an 8GB machine, the default cache is too small for all of
> WebKit to fit in it.
>
> On my 4GB machine (and on Mark's 8GB) we tried incrementing the cache
> to 384000 (the 4GB default is 64512 and the 8GB default is 128000).
>
> My git status times dropped again by over 50% to 2.6 seconds! (still
> an eternity compared to a linux machine of course...)
>
> If you'd like to play around with this, you can set your vnode cache limit
> with:
> sudo sysctl -w kern.maxvnodes=384000
>
> You can read it with:
> sysctl kern.maxvnodes
>
> You can test to see if the cache is large enough by trying:
> git status; time git status
>
> the second one should be very fast if your cache is large enough.
>
> I don't know what the exact right trade-off is.  I believe the vnode
> cache uses wired memory (which is a limited resource!).  As far as I
> can tell you can't decrease the cache max w/o rebooting.  sysctl will
> set it, but setting it to a smaller number seems to have not effect.
>
> I don't know how to make the setting last across reboots.  Mark
> mentioned that putting the setting in /etc/sysctl.conf should work,
> but that at least for his machine that didn't seem to have any effect
> for this particular setting.
>
> That's what I know.
>
> -eric
>
>
> On Wed, Dec 8, 2010 at 3:02 PM, Eric Seidel <eric at webkit.org> wrote:
> >
> > FYI, my git status runs on my Mac Book Pro were an average of 9.2 seconds
> (git version 1.7.1, git-osx-installer) before installing Mihai's 64bit build
> (git version 1.7.3.3), and were 6.0 seconds after.
> > -eric
> >
> > On Wed, Dec 8, 2010 at 2:20 PM, Eric Seidel <eric at webkit.org> wrote:
> >>
> >> I've posted a patch to make webkit-patch warn users when they're on a
> 64-bit system with a 32-bit git:
> >> https://bugs.webkit.org/show_bug.cgi?id=50715
> >> 4 seconds on every git status is huge.  webkit-patch upload has to run
> at least 3 git status commands (due to expecting files to change on disk
> during operation), so this means a savings of 12 seconds on your machine!
> >> -eric
> >> On Tue, Dec 7, 2010 at 4:04 PM, Mihai Parparita <mihaip at chromium.org>
> wrote:
> >>>
> >>> After complaining to a Linux-using friend for the n-th time that "git
> >>> status" was much slower on my Snow Leopard machine than on his Linux
> >>> box, I decided to look into why this is. As it turns out, most people
> >>> get git binaries from http://code.google.com/p/git-osx-installer/,
> >>> which are 32-bit. Switching to 64-bit binaries made git status go from
> >>> 6.58s to 2.50s (mainly because this does fewer mmaps).
> >>>
> >>> You can download a 64-bit binary installer from
> >>>
> https://github.com/downloads/mihaip/git_osx_installer/git-1.7.3.3-intel-x86_64-leopard.dmg
> ,
> >>> or you can build it yourself (more details at
> >>>
> http://blog.persistent.info/2010/12/making-git-faster-on-large-repositories.html
> ).
> >>>
> >>> Mihai
> >>> _______________________________________________
> >>> webkit-dev mailing list
> >>> webkit-dev at lists.webkit.org
> >>> http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
> >>
> >
> _______________________________________________
> webkit-dev mailing list
> webkit-dev at lists.webkit.org
> http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-dev/attachments/20101209/892a7f0b/attachment.html>