trace malloc for x86_64 Mac OS X builds is too slow

RESOLVED FIXED

Status

()

Core
XPCOM
RESOLVED FIXED
7 years ago
6 years ago

People

(Reporter: Josh Aas, Unassigned)

Tracking

Trunk
x86_64
Mac OS X
Points:
---
Dependency tree / graph

Firefox Tracking Flags

(Not tracked)

Details

Attachments

(3 attachments)

(Reporter)

Description

7 years ago
I believe the cause for bug 558496 is that trace malloc runs incredibly slowly on x86_64 Mac OS X builds. The slowdown appears to be worse than 10x, possibly 20x or so, leading to the 3600 second timeout. I can reproduce this behavior locally on a Mac Pro, and the problem goes away on my machine and the Mac Mini build slave if I run tests without trace malloc.
(Reporter)

Updated

7 years ago
Blocks: 558496
(Reporter)

Comment 1

7 years ago
Created attachment 452906 [details]
sample 1, app startup

This sample was taken during app startup and as expected, 'findClosestSymbol' dominates.
(Reporter)

Comment 2

7 years ago
Created attachment 452908 [details]
sample 2, network load

This sample was taken during the first network load, after:

localhost - - [21/Jun/2010 20:01:08] "GET /bloatcycle.html HTTP/1.1" 200 -
(Reporter)

Comment 3

7 years ago
Created attachment 452913 [details]
sample 2, network load, expanded

Same as sample 2 but with the stack expanded.
Is findClosestSymbol called from within dladdr?
So one possibility here is that the calltree locking is much too fine-grained; I think I've been concerned about that in the past.
(Reporter)

Comment 6

7 years ago
(In reply to comment #4)
> Is findClosestSymbol called from within dladdr?

Yes:

dyld ImageLoaderMachOCompressed::findClosestSymbol(void const*, void const**) const
dyld dladdr
XUL NS_DescribeCodeAddress

Updated

7 years ago
Blocks: 581077

Comment 7

6 years ago
Anyone that can be working on this?

We are trying to move the 10.5 leak builds to be run on 10.6 minis in bug 674647 and we are hitting this problem.
Blocks: 674647
I think this was fixed with bug 696281. Can someone check?

Comment 9

6 years ago
We seemed to have fixed the slowness (few good runs showed only 1 minute on running alive_tests2) but we have resuscitated bug 558496.
This was fixed in https://hg.mozilla.org/mozilla-central/rev/c9a74f4ee1f7
Status: NEW → RESOLVED
Last Resolved: 6 years ago
Resolution: --- → FIXED
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