Revision: 13090
Author: [email protected]
Date: Thu Nov 29 04:47:21 2012
Log: Edited wiki page V8Profiler through web user interface.
http://code.google.com/p/v8/source/detail?r=13090
Modified:
/wiki/V8Profiler.wiki
=======================================
--- /wiki/V8Profiler.wiki Thu Jan 21 14:52:00 2010
+++ /wiki/V8Profiler.wiki Thu Nov 29 04:47:21 2012
@@ -5,40 +5,30 @@
V8 has built-in sample based profiling. Profiling is turned off by
default, but can be enabled via the --prof command line option. The sampler
records stacks of both JavaScript and C/C++ code.
= Build =
-V8 must be built with `ENABLE_LOGGING_AND_PROFILING` in order to be used.
This macro is defined by default.
+Build the d8 shell following the instructions at [BuildingWithGYP].
-= Windows =
-Symbol resolution is done using a `.MAP` file, so the application must be
linked to generate a `.MAP` file containing symbol information. Using the
SCons `prof` option will make a `.MAP` file be generated for the target.
-
-{{{
-scons prof=on
-}}}
-
-In Visual Studio 2005 the option for generation a `.MAP` file can be found
on the property page under _Configuration Properties->Linker->Debugging_.
= Command Line =
-To start profiling, use the `--prof` option. When profiling, v8 generates
a `v8.log` file which contains profiling data.
+To start profiling, use the `--prof` option. When profiling, V8 generates
a `v8.log` file which contains profiling data.
Windows:
{{{
-v8_shell_sample --prof script.js
+build\Release\d8 --prof script.js
}}}
-Other platforms:
+Other platforms (replace "ia32" with "x64" if you want to profile the x64
build):
{{{
-./shell --prof script.js
+out/ia32.release/d8 --prof script.js
}}}
= Process the Generated Output =
-Log file processing is done using JS scripts running by the d8 shell.
Under Windows the d8 shell must be built manually because there are
multiple way of building (SCons, VS.) Under `*`nix-like platforms, the
linux-tick-processor script automatically calls SCons in order to build the
d8 shell executable.
+Log file processing is done using JS scripts running by the d8 shell. For
this to work, a `d8` binary (or symlink, or `d8.exe` on Windows) must be in
the root of your V8 checkout, or in the path specified by the environment
variable `D8_PATH`. Note: this binary is just used to process the log, but
not for the actual profiling, so it doesn't matter which version etc. it is.
Windows:
{{{
tools\windows-tick-processor.bat v8.log
}}}
-
-`windows-tick-processor.bat` script assumes that `d8.exe` resides in the
project root directory.
Linux:
{{{
@@ -52,7 +42,7 @@
== Snapshot-based VM build and builtins reporting ==
-When a snapshot-based VM build is being used, code objects from a snapshot
that doesn't correspond to function objects are reported with generic names
like _"A builtin from the snapshot"_, because their real names are not
stored in the snapshot. To see the names the following steps must be taken:
+When a snapshot-based VM build is being used, code objects from a snapshot
that don't correspond to functions are reported with generic names like _"A
builtin from the snapshot"_, because their real names are not stored in the
snapshot. To see the names the following steps must be taken:
* `--log-snapshot-positions` flag must be passed to VM (along with
`--prof`); this way, for deserialized objects the `(memory address,
snapshot offset)` pairs are being emitted into profiler log;
@@ -60,8 +50,8 @@
An example of usage:
{{{
-./shell --prof --log-snapshot-positions script.js
-tools/linux-tick-processor --snapshot-log=obj/release/snapshot.log v8.log
+out/ia32.release/d8 --prof --log-snapshot-positions script.js
+tools/linux-tick-processor
--snapshot-log=out/ia32.release/obj.target/v8_snapshot/geni/snapshot.log
v8.log
}}}
= Programmatic Control of Profiling =
--
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