Extend CPU profiler with mapping ticks to source lines

Extend CPU profiler with mapping ticks to source lines

The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers.
During generation code and relocation info are generated simultaneously.
When code generation is done you each code object has associated "relocation info".
Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection),
correspondences between the machine program counter and source locations for stack walking.

This patch:
1. Add more source positions info in reloc info to make it suitable for source level mapping.
The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and
(2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other).
I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark).

2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line.
If a source line is found that hit counter is increased by one for this line.

3. Add a new public V8 API to get the hit source lines by CDT CPU profiler.
Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown.

4.Add a test that checks how the samples are distributed through source lines.
It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version.

Patch from Denis Pravdin <denis.pravdin@intel.com>;
BUG=None
LOG=Y
R=svenpanne@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=24389

[yurys, 2014-10-02 08:40:33]

yurys@chromium.org changed reviewers:
+ alph@chromium.org, danno@chromium.org, denis.pravdin@intel.com,
svenpanne@chromium.org, weiliang.lin@intel.com, yurys@chromium.org

[yurys, 2014-10-02 08:40:34]

Patch set #1 is exact copy of https://codereview.chromium.org/424973004/. I
moved implementation JITLineInfoTable into profile-generator.cc (PS#2) and fixed
x64.debug linker failure (PS#3)

[yurys, 2014-10-02 08:42:20]

Sven, can you stamp this please?

[Sven Panne, 2014-10-02 08:43:30]

lgtm

[yurys, 2014-10-02 09:20:48]

Committed patchset #3 (id:40001) manually as 24389 (presubmit successful).

[yurys, 2014-10-02 11:52:37]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/624443005/ by yurys@chromium.org.

The reason for reverting is: It broke layout test
fast/events/window-onerror-02.html:

http://build.chromium.org/p/client.v8/builders/V8-Blink%20Linux%2064%20%28dbg....

[Denis Pravdin, 2014-10-03 07:50:23]

On 2014/10/02 11:52:37, yurys wrote:
> A revert of this CL (patchset #3 id:40001) has been created in
> https://codereview.chromium.org/624443005/ by mailto:yurys@chromium.org.
> 
> The reason for reverting is: It broke layout test
> fast/events/window-onerror-02.html:
> 
>
http://build.chromium.org/p/client.v8/builders/V8-Blink%20Linux%2064%20%28dbg....

Yurys,

Which steps are expected in this case from my end? I should triage why the test
fails and fix it. Once it's done that a new patch should be uploaded for review.
Right?

Thanks,
Denis

[yurys, 2014-10-03 08:03:42]

On 2014/10/03 07:50:23, Denis Pravdin wrote:
> On 2014/10/02 11:52:37, yurys wrote:
> > A revert of this CL (patchset #3 id:40001) has been created in
> > https://codereview.chromium.org/624443005/ by mailto:yurys@chromium.org.
> > 
> > The reason for reverting is: It broke layout test
> > fast/events/window-onerror-02.html:
> > 
> >
>
http://build.chromium.org/p/client.v8/builders/V8-Blink%20Linux%2064%20%28dbg....
> 
> Yurys,
> 
> Which steps are expected in this case from my end? I should triage why the
test
> fails and fix it. Once it's done that a new patch should be uploaded for
review.
> Right?
> 
Correct. Looks like your patch regresses behavior of window.onerror so this
needs to be fixed before landing. You can reproduce it by checking out and
building Blink, instructions for running layout tests can be found at
http://www.chromium.org/developers/testing/webkit-layout-tests#TOC-Running-th...

Alternatively if you don't want to build Blink you can try to come up with a
reduced test case that could be executed with bare V8. The error event passed
into window.onerror is constructed based on the data passed into message
listener added to v8 via v8::V8::AddMessageListener();. So you can probably add
a new test to test/cctest/ that would execute script similar to the one in
fast/events/window-onerror-02.htm and check that the error column passed into
the message listener is correct.



> Thanks,
> Denis

[Denis Pravdin, 2014-10-03 08:07:33]

On 2014/10/03 08:03:42, yurys wrote:
> On 2014/10/03 07:50:23, Denis Pravdin wrote:
> > On 2014/10/02 11:52:37, yurys wrote:
> > > A revert of this CL (patchset #3 id:40001) has been created in
> > > https://codereview.chromium.org/624443005/ by mailto:yurys@chromium.org.
> > > 
> > > The reason for reverting is: It broke layout test
> > > fast/events/window-onerror-02.html:
> > > 
> > >
> >
>
http://build.chromium.org/p/client.v8/builders/V8-Blink%20Linux%2064%20%28dbg....
> > 
> > Yurys,
> > 
> > Which steps are expected in this case from my end? I should triage why the
> test
> > fails and fix it. Once it's done that a new patch should be uploaded for
> review.
> > Right?
> > 
> Correct. Looks like your patch regresses behavior of window.onerror so this
> needs to be fixed before landing. You can reproduce it by checking out and
> building Blink, instructions for running layout tests can be found at
>
http://www.chromium.org/developers/testing/webkit-layout-tests#TOC-Running-th...
> 
> Alternatively if you don't want to build Blink you can try to come up with a
> reduced test case that could be executed with bare V8. The error event passed
> into window.onerror is constructed based on the data passed into message
> listener added to v8 via v8::V8::AddMessageListener();. So you can probably
add
> a new test to test/cctest/ that would execute script similar to the one in
> fast/events/window-onerror-02.htm and check that the error column passed into
> the message listener is correct.
> 
> 
> 
> > Thanks,
> > Denis

Got it. Thanks for advice!