Tracks the usage of executable memory allocated by V8 and exposes the value t...

Tracks the maximum usage of executable memory allocated by V8 and allows the histogram data to be gathered and reported.

This patch is contains only the usage tracking logic from 3030048 (already LGTM'd). It does not implement the RWX Limit.

BUG=52122
TEST=Check the V8.ExecutableMemoryMax histogram in the Chrome about:histograms page

Committed: http://code.google.com/p/v8/source/detail?r=5299

[Valoo, 2010-08-17 17:13:37]

It looks like codereview never sent emails to at least some  of the reviewers,
so this is for those that didn't get it initially.  Sorry if this is a repeat.

[Søren Thygesen Gjesse, 2010-08-18 08:20:01]

LGTM

http://codereview.chromium.org/3161015/diff/10002/37005
File src/spaces.cc (right):

http://codereview.chromium.org/3161015/diff/10002/37005#newcode296
src/spaces.cc:296: #if defined(V8_REPORT_EXECUTABLE_MEMORY_USAGE)
I don't think we need this conditional compile unless this will have performance
impact being on by default.

[Søren Thygesen Gjesse, 2010-08-18 09:36:26]

Without this change most of the tests crashed during heap teardown.

http://codereview.chromium.org/3161015/diff/10002/37005
File src/spaces.cc (right):

http://codereview.chromium.org/3161015/diff/10002/37005#newcode2617
src/spaces.cc:2617: Page* page = Page::FromAddress(chunk->address());
This line should be:

Page* page = Page::FromAddress(RoundUp(current->address(), Page::kPageSize));

[Søren Thygesen Gjesse, 2010-08-18 10:46:37]

On 2010/08/18 09:36:26, Søren Gjesse wrote:
> Without this change most of the tests crashed during heap teardown.
> 
> http://codereview.chromium.org/3161015/diff/10002/37005
> File src/spaces.cc (right):
> 
> http://codereview.chromium.org/3161015/diff/10002/37005#newcode2617
> src/spaces.cc:2617: Page* page = Page::FromAddress(chunk->address());
> This line should be:
> 
> Page* page = Page::FromAddress(RoundUp(current->address(), Page::kPageSize));

Committed as r5299 with suggested changes above applied.

Closing issue.