code review 207044: runtime: garbage collection + malloc performance

runtime: garbage collection + malloc performance
  * add bit tracking finalizer status, avoiding getfinalizer lookup
  * add ability to allocate uncleared memory

[rsc, 2010-02-10 04:42:29]

Hello iant (cc: golang-dev@googlegroups.com),

I'd like you to review this change.

[iant, 2010-02-10 06:03:49]

LGTM

http://codereview.appspot.com/207044/diff/1042/43
File src/pkg/runtime/malloc.cgo (right):

http://codereview.appspot.com/207044/diff/1042/43#newcode185
src/pkg/runtime/malloc.cgo:185: /*
Any particular reason to comment this out?

http://codereview.appspot.com/207044/diff/1042/46
File src/pkg/runtime/mcentral.c (right):

http://codereview.appspot.com/207044/diff/1042/46#newcode151
src/pkg/runtime/mcentral.c:151: p->next = nil;
Looks like you are setting p->next = nil twice.  The second one is unnecessary.

[rsc, 2010-02-10 06:08:59]

> http://codereview.appspot.com/207044/diff/1042/43#newcode185
> src/pkg/runtime/malloc.cgo:185: /*
> Any particular reason to comment this out?

It's good for error checking but is noticeably expensive.
mlookup is the bottleneck for the tracing phase of
the garbage collector.  I'll add a comment.

> http://codereview.appspot.com/207044/diff/1042/46#newcode151
> src/pkg/runtime/mcentral.c:151: p->next = nil;
> Looks like you are setting p->next = nil twice.  The second one is
> unnecessary.

Thanks.

Russ

[rsc, 2010-02-10 08:00:15]

*** Submitted as http://code.google.com/p/go/source/detail?r=ea6542b375e9 ***

runtime: garbage collection + malloc performance
  * add bit tracking finalizer status, avoiding getfinalizer lookup
  * add ability to allocate uncleared memory

R=iant
CC=golang-dev
http://codereview.appspot.com/207044