This CL introduces static variables and global lock for writing to the
dump files, so that multiple web workers do not run into trouble.
Review URL: https://codereview.chromium.org/1839133002
Cr-Commit-Position: refs/heads/master@{#35123}
This fixes support for debug info in perf. Thanks to Stephane Eranian for
identifying the problem - debug info event has to be emitted before the
code load event. It also seems that perf does not yet support the shorthand
for repeated source files in the debug info entry ("\xff\0"), so I changed
it to always write the script name.
Review URL: https://codereview.chromium.org/1843563002
Cr-Commit-Position: refs/heads/master@{#35092}
Difference from --perf-basic-prof:
- correctly attributes samples when code space gets reused (when unused code object dies and a new code objects is allocated at the same place).
- outputs compiled machine code for instruction-level profile.
Just like --perf-basic-prof, the file writer is not synchronized (even worse, there is a per-isolate file handle), so we will run into trouble with multiple isolates. However, this patch is still an improvement on --perf-basic-prof, and it should be fine to replace ll-prof.
The patch also introduces experimental support for debug info, but it does not seem to be picked by the perf tool.
Usage:
You need the perf tool from Linux kernel >4.5. Then run:
$ perf record -k mono d8 --perf-prof <your JS file>
$ perf inject -j -i perf.data -o perf.data.jitted
$ perf report -i perf.data.jitted
Some explanations:
The "-k mono" switch from "perf record" tells the perf tool to use the monotonic clock for perf sample timestamping. The "perf inject -j" command injects the collected code events into the perf data file, writing the output into perf.data.jitted. The perf report command then creates the report.
Review URL: https://codereview.chromium.org/1809203007
Cr-Commit-Position: refs/heads/master@{#35091}
This adds timestamps to allow profiling with code space reuse. Also a couple of updates to reflect the changes in the JIT perf interface + a move of the perf-related stuff into separate files.
Unfortunately, the change only works with the latest patch to the perf tool from a Linux perf tool contributor (Stephane Eranian).
BUG=
R=yangguo@chromium.org
Review URL: https://codereview.chromium.org/255803003
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22098 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
