Bug 121045

Summary: CopiedSpace::startedCopying should not call MarkedSpace::capacity
Product: WebKit Reporter: Mark Hahnenberg <mhahnenberg>
Component: JavaScriptCoreAssignee: Mark Hahnenberg <mhahnenberg>
Status: RESOLVED FIXED    
Severity: Normal    
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on:    
Bug Blocks: 121074    
Attachments:
Description Flags
Patch
none
Patch ggaren: review+

Description Mark Hahnenberg 2013-09-09 13:51:27 PDT 
MarkedSpace::capacity() iterates every block in MarkedSpace. Heap has m_totalBytesVisited, which is a good enough approximation of the size of MarkedSpace and it's O(1) so we should use it instead.
Comment 1 Mark Hahnenberg 2013-09-09 13:52:38 PDT 
Created attachment 211079 [details]
Patch
Comment 2 Mark Hahnenberg 2013-09-09 17:13:21 PDT 
Created attachment 211123 [details]
Patch
Comment 3 Mark Hahnenberg 2013-09-09 17:14:45 PDT 
I was getting a small but persistent slow down on kraken with the first version, so I tried just keeping track as we add and remove MarkedBlocks from the MarkedSpace. This version didn't show any slowdown.
Comment 4 Geoffrey Garen 2013-09-09 17:17:35 PDT 
Comment on attachment 211123 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=211123&action=review

r=me

> Source/JavaScriptCore/heap/MarkedSpace.h:135
> +    size_t m_totalCapacity;

I think "capacity" is a slightly better name here. We don't have a concept of "partial capacity" in this class.
Comment 5 Mark Hahnenberg 2013-09-09 17:34:19 PDT 
Committed r155406: <http://trac.webkit.org/changeset/155406>