Bug 39758

Summary:

Heap::allocate should search a word at a time

Product:

WebKit

Reporter:

Nathan Lawrence <nlawrence>

Component:

JavaScriptCore

Assignee:

Nathan Lawrence <nlawrence>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

commit-queue, ggaren, nlawrence, slewis

Priority:

Version:

528+ (Nightly build)

Hardware:

All

OS:

All

Attachments:

Description	Flags
suggested patch	ggaren: review-
Moved the advance logic from Heap::allocate to CollectorBitmap::advanceToNextPossibleFreeCell.	none

Nathan Lawrence

Reported 2010-05-26 12:59:00 PDT

Currently, Heap::allocate is searching for a new cell in the bitmap a single bit at a time. This can be improved by searching a word at a time in the bitmap when our first guess fails.

Attachments
suggested patch (748 bytes, patch) 2010-05-26 13:00 PDT, Nathan Lawrence	ggaren: review-	Details Formatted Diff Diff
Moved the advance logic from Heap::allocate to CollectorBitmap::advanceToNextPossibleFreeCell. (2.12 KB, patch) 2010-05-26 14:04 PDT, Nathan Lawrence	no flags	Details Formatted Diff Diff
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.

Nathan Lawrence

Comment 1 2010-05-26 13:00:03 PDT

Created attachment 57126 [details] suggested patch

Geoffrey Garen

Comment 2 2010-05-26 13:10:20 PDT

Comment on attachment 57126 [details] suggested patch + if (!~block->marked.bits[m_heap.nextCell >> 5]) + m_heap.nextCell = (m_heap.nextCell & (~0x1F)) + 32; I think this code might be wrong on 64bit. Also, would be nice to encapsulate these bitops in the CollectorBitmap interface. Let's talk about this in person.

Nathan Lawrence

Comment 3 2010-05-26 14:04:56 PDT

Created attachment 57132 [details] Moved the advance logic from Heap::allocate to CollectorBitmap::advanceToNextPossibleFreeCell. Hey, I uploaded the patch to the correct bug this time!

Geoffrey Garen

Comment 4 2010-05-26 14:10:59 PDT

Comment on attachment 57132 [details] Moved the advance logic from Heap::allocate to CollectorBitmap::advanceToNextPossibleFreeCell. r=me

Geoffrey Garen

Comment 5 2010-05-27 13:30:05 PDT

Comment on attachment 57132 [details] Moved the advance logic from Heap::allocate to CollectorBitmap::advanceToNextPossibleFreeCell. Let's have auto-Eric take a crack at committing this.

WebKit Commit Bot

Comment 6 2010-05-27 14:45:22 PDT

Comment on attachment 57132 [details] Moved the advance logic from Heap::allocate to CollectorBitmap::advanceToNextPossibleFreeCell. Clearing flags on attachment: 57132 Committed r60323: <http://trac.webkit.org/changeset/60323>

WebKit Commit Bot

Comment 7 2010-05-27 14:45:28 PDT

All reviewed patches have been landed. Closing bug.

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