1537781 - Trailing guard pages for normal allocations

Status: RESOLVED FIXED

(Core :: Memory Allocator, enhancement)

Description

[Gian-Carlo Pascutto [:gcp]]

+++ This bug was initially created as a clone of Bug #1529922 +++

Split off from bug 1446040. Trailing guard pages for huge allocations were done in the first patch, this adds them for normal allocations.

Comment 1

[Gian-Carlo Pascutto [:gcp]]

I'm cleaning all codepaths to take the COMMIT/DECOMMIT paths, and while I was wondering why we weren't doing this before, I noticed this comment:
https://github.com/jemalloc/jemalloc/issues/261#issuecomment-137308537

Which seems to imply glandium has tested this on macOS already.

Comment 2

[Gian-Carlo Pascutto [:gcp]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=c99335a711cd8dd307ef9866e7fdb572ed4daf17

Comment 3

[Gian-Carlo Pascutto [:gcp]]

Attachment: Bug 1537781 - Remove all DECOMMIT/DOUBLE_PURGE logic. r=glandium

Depends on D21566

Comment 4

[Gian-Carlo Pascutto [:gcp]]

Attachment: Bug 1537781 - Guard pages for normal allocations. r=glandium

Comment 5

[Gian-Carlo Pascutto [:gcp]]

Attachment: Bug 1537781 - Add a test for guard regions in runs. r=glandium

Depends on D21565

Comment 6

[Gian-Carlo Pascutto [:gcp]]

So, the only worrisome part is an ASAN failure, but IIRC, ASAN builds don't use malloc?!

Comment 7

[Gian-Carlo Pascutto [:gcp]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=77762430fde2954f7acfe906e7f9f818a1767af3

Comment 8

[Gian-Carlo Pascutto [:gcp]]

Attachment: Bug 1537781 - Trailing guard pages for normal allocations. r?glandium

Depends on D26351

Comment 9

[Gian-Carlo Pascutto [:gcp]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=b2db9db56ff5b74f929221afe97f6183f4d7f9e4

Comment 10

[Gian-Carlo Pascutto [:gcp]]

Talos for only guarding 1 page per chunk, so this bug but with the dependency on bug 1542290 removed.
https://treeherder.mozilla.org/#/jobs?repo=try&revision=2abc01bd9cfe7a8d8a78ec27a6d6b8e0e9edc3f5

Comment 11

[Gian-Carlo Pascutto [:gcp]]

Talos for only guarding 1 page per chunk, so this bug but with the dependency on bug 1542290 removed.

As expected, this is mostly a wash.

Comment 12

[Gian-Carlo Pascutto [:gcp]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=f1d1868c4f90971dcf9b77d3ac2faaa4e482ce01

Comment 13

[Gian-Carlo Pascutto [:gcp]]

Attachment: Bug 1537781 - Trailing guard pages for normal allocations. r?glandium

Comment 14

[Gian-Carlo Pascutto [:gcp]]

Attachment: Bug 1537781 - Test for trailing guard pages for normal allocations. r?glandium

Depends on D27912

Comment 15

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/dd542aa67434
Trailing guard pages for normal allocations. r=glandium

Comment 16

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7a92af28d8e1
Test for trailing guard pages for normal allocations. r=glandium

Comment 17

[Raul Gurzau (:RaulG)]

https://hg.mozilla.org/mozilla-central/rev/dd542aa67434
https://hg.mozilla.org/mozilla-central/rev/7a92af28d8e1

Comment 18

[Alexandru Ionescu (needinfo me) [:alexandrui]]

Hi :gcp, look like your patch indeed came with this improvement:
== Change summary for alert #21621 (as of Thu, 27 Jun 2019 04:15:05 GMT) ==

Improvements:

5% Resident Memory linux64-shippable opt 667,984,142.65 -> 633,197,812.91
5% Resident Memory linux64-shippable opt 664,312,554.01 -> 631,185,026.74

For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=21621