478701 - Speed up startup by pre-warming xul.dll and common files

Status: RESOLVED INVALID

(Core :: General, defect)

Description

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Attachment: proof-of-concept warm start patch

With this patch, startup on my Windows CE 6 device goes from 60-120s to 5s.  The patch would apply equally well to desktop and even to unixen, if the right code bits were used.  We may be able to use nspr here as well, since I'm pretty sure it will have been loaded into memory already due to the ScopedLogging.

Patch is just a proof-of-concept, but it's not far off from final.  Note that I put it here, and not in XRE_main, so that we get a chance to do this preread as early as possible, before libxul bits are bound.

Reading libxul + these 3 files took 1700ms total (1300ms for libxul, the rest for the others) from my somewhat slow flash card.

Comment 1

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Attachment: better patch

Ok, this actually grabs the binary location and finds xul.dll wherever it's at.

Comment 2

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Attachment: er, real better patch

Previous patch had some cruft in it.

Comment 3

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

this doesn't actually help; I was fooled by some other tools causing a massive slowdown during startup.  Alas.