Revision: 5477
Author: mikhail.naganov
Date: Thu Sep 16 05:29:36 2010
Log: Updated according to recent changes in V8 <-> DevTools profiles
transport.
http://code.google.com/p/v8/source/detail?r=5477
Modified:
/wiki/ProfilingChromiumWithV8.wiki
=======================================
--- /wiki/ProfilingChromiumWithV8.wiki Fri Sep 18 04:24:24 2009
+++ /wiki/ProfilingChromiumWithV8.wiki Thu Sep 16 05:29:36 2010
@@ -16,43 +16,31 @@
* Developer Tools configure profilers for their own purposes;
* V8's logging code contains some optimizations to simplify logging
state checks.
-== Recipe ingredients ==
-
-You need to pass several flags to Chromium in order to get the results you
want. Let's discuss each flag in detail.
-
- * *--no-sandbox* - turns off the renderer sandbox, obviously must have;
- * *--js-flags* - this is the containers for flags passed to V8:
- * *--logfile=%t.log* - specifies a name pattern for log files; *%t*
gets expanded into current time in milliseconds, so each process gets its
own log file; you can use prefixes and suffixes if you want, like this:
*prefix-%t-suffix.log*;
- * *--noprof-lazy* - allows shared libraries entries to be logged upon
CPU profiler initialization;
- * *--prof-auto* / *--noprof-auto* - controls whether CPU profiling
should start immediately after V8 initialization, or be controlled via
Developer Tools Profiles pane;
- * *--nocompress-log* - disables log contents compression which makes
them unreadable for humans (but they still can be processed with V8's tick
processor scripts);
- * *--log-gc* - controls logging of heap contents on garbage
collections (Heap profiling).
-
-== The cookbook ==
-
-Now having an understanding what behavior is controlled by which flag,
let's combine them.
+== So, how to run Chromium to get a CPU profile? ==
Here is how to run Chromium in order to get a CPU profile from the start
of the process:
{{{
./Chromium --no-sandbox --js-flags="--logfile=%t.log --noprof-lazy
--prof-auto"
}}}
-If you want to start / stop CPU profiling manually using Developer Tools
Profiles pane, use *--noprof-auto*:
-{{{
-./Chromium --no-sandbox --js-flags="--logfile=%t.log --noprof-lazy
--noprof-auto"
-}}}
-
-To have heap usage statistics logged continuously, run Chromium like this:
+or
+
{{{
-./Chromium --no-sandbox --js-flags="--logfile=%t.log --log-gc"
+./Chromium --no-sandbox --js-flags="--logfile=%t.log --noprof-lazy
--prof-auto --nocompress-log"
}}}
-To log heap usage statistics manually using Developer Tools Heap pane:
-{{{
-./Chromium --no-sandbox --js-flags="--logfile=%t.log"
-}}}
-
-Please note that when using manual controls for profiles creation, you
wouldn't see profiles in Developer Tools, because all the data is being
logged to a file, not to Developer Tools.
+if you want to be able to parse logs with your eyes.
+
+Please note that you wouldn't see profiles in Developer Tools, because all
the data is being logged to a file, not to Developer Tools.
+
+=== Flags description ===
+
+ * *--no-sandbox* - turns off the renderer sandbox, obviously must have;
+ * *--js-flags* - this is the containers for flags passed to V8:
+ * *--logfile=%t.log* - specifies a name pattern for log files; *%t*
gets expanded into current time in milliseconds, so each process gets its
own log file; you can use prefixes and suffixes if you want, like this:
*prefix-%t-suffix.log*;
+ * *--noprof-lazy* - allows shared libraries entries to be logged upon
CPU profiler initialization;
+ * *--prof-auto* - tells that CPU profiling should start immediately
after V8 initialization;
+ * *--nocompress-log* - disables log contents compression which makes
them unreadable for humans (but they still can be processed with V8's tick
processor scripts).
== Notes ==
--
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[email protected]
http://groups.google.com/group/v8-dev
