1529558 - Use PrefetchVirtualMemory in nsZipArchive::BuildFileList when supported, instead of ReadAhead

Status: RESOLVED FIXED

(Core :: Networking: JAR, enhancement, P1)

Description

[Mike Hommey [:glandium]]

See bug 1376994 comment 8

Comment 1

[(No longer employed by Mozilla) Aaron Klotz]

I'd suggest gating this on the successful resolution of PrefetchVirtualMemory, instead of using IsWin8OrLater.

Comment 2

[Mike Hommey [:glandium]]

Attachment: Bug 1529558 - Use PrefetchVirtualMemory in nsZipArchive::BuildFileList when supported.

instead of ReadAhead, which does active reading on Windows.

The PrefetchVirtualMemory is a system call that is new to Windows 8.

Back when the readahead code for jar was added, in bug 810151, Windows 8
was still fresh out of the oven. 6 years later, we can do a runtime
check and use the PrefetchVirtualMemory function.

One downside is that the IOInterposer doesn't know about it (but it
doesn't know about madvise on other platforms anyways).

Comment 3

[Mike Hommey [:glandium]]

I verified this works as expected, but that required editing omni.ja manually, because it turns out for some reason, they don't have readahead information at the moment. Filed bug 1529894.

Comment 4

[Junior [inactive]]

P1 given Mike is already working on this

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a716ff1b62ab
Use PrefetchVirtualMemory in nsZipArchive::BuildFileList when supported. r=aklotz

Comment 6

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/a716ff1b62ab