1342023 - Remove ProtectedReallocPolicy when we're done using it

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, defect, P2)

Description

[Emanuel Hoogeveen [:ehoogeveen]]

ProtectedReallocPolicy in ds/PageProtectingVector.h is becoming more and more specialized, and its internals have already changed several times. After we're done using it to debug bug 1124397 we should remove it.

Comment 1

[Emanuel Hoogeveen [:ehoogeveen]]

Marking this P2 for now, though I suspect we'll be done with it soon.

Comment 2

[Emanuel Hoogeveen [:ehoogeveen]]

Attachment: Part 1: Remove ProtectedReallocPolicy from PageProtectingVector.

I think it's about time. We still don't know what's going wrong in jemalloc but we've narrowed down the problem as much as we can and it's clear that the Windows crashes are due to bad hardware. The only disadvantage to removing this code is that the crashes will move to a different signature, but we never enabled this on Beta or Release anyway.

Comment 3

[Emanuel Hoogeveen [:ehoogeveen]]

Attachment: Part 2: Stop using PageProtectingVector in AssemblerBuffer.

And remove the rest. I think this is everything, try run to make sure: https://treeherder.mozilla.org/#/jobs?repo=try&revision=63d898a06c26ad440d254d9bdb55b6b0fc19d68a

This should be a nice speedup for certain cases on Nightly, though I don't expect anything too major.

Comment 4

[Jan de Mooij [:jandem]]

Comment on attachment 8889915 [details] [diff] [review]
Part 1: Remove ProtectedReallocPolicy from PageProtectingVector.

Review of attachment 8889915 [details] [diff] [review]:
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Thanks.

Comment 5

[Jan de Mooij [:jandem]]

Comment on attachment 8889916 [details] [diff] [review]
Part 2: Stop using PageProtectingVector in AssemblerBuffer.

Review of attachment 8889916 [details] [diff] [review]:
-----------------------------------------------------------------

Will be interesting to see if this helps perf somewhere :)

Comment 6

[Emanuel Hoogeveen [:ehoogeveen]]

Attachment: Part 1: Remove ProtectedReallocPolicy from PageProtectingVector.

Comment 7

[Emanuel Hoogeveen [:ehoogeveen]]

Attachment: Part 2 v1.1: Stop using PageProtectingVector in AssemblerBuffer.

I actually missed a few instances, ARM mostly. Guess Try didn't catch it because they were all no ops. Trivial change, carrying forward r+.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/20da293c7656
Part 1: Remove ProtectedReallocPolicy from PageProtectingVector. r=jandem
https://hg.mozilla.org/integration/mozilla-inbound/rev/3144b8254557
Part 2: Stop using PageProtectingVector in AssemblerBuffer. r=jandem

Comment 9

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/20da293c7656
https://hg.mozilla.org/mozilla-central/rev/3144b8254557