516853 - TM: InitGC now takes 125ms to run on Mac

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[David Mandelin [:dmandelin]]

Attachment: Patch

I discovered that this:

#ifdef __APPLE__
    memset((void *)rt->gcBase, 0, bytes);
#endif

adds about 1/8 of a second to startup time. This is particularly painful for running test suites requiring 100-3000 invocations.

Andreas said to take it out and file a new bug to do the memory touching more efficiently.

Comment 1

[Andreas Gal :gal]

The sad sob story of MacOSX page fault performance continues.

Comment 2

[David Mandelin [:dmandelin]]

Pushed to TM as 615b519de189.

Comment 3

[Andreas Gal :gal]

With the patch applied we only lose 9ms in the shell for SS so lets not worry too much (I don't think this affects the browser at all).

Comment 4

[Mike Shaver (:shaver emeritus)]

calloc?

Comment 5

[Blake Kaplan (:mrbkap) (inactive)]

http://hg.mozilla.org/mozilla-central/rev/615b519de189

Comment 6

[Robert Sayre]

http://hg.mozilla.org/releases/mozilla-1.9.2/rev/e6665e2ea6f7