Bug 104647

Summary: Profiler should show bytecode dumps as they would have been visible to the JITs, including the profiling data that the JITs would see
Product: WebKit Reporter: Filip Pizlo <fpizlo>
Component: JavaScriptCoreAssignee: Filip Pizlo <fpizlo>
Status: RESOLVED FIXED    
Severity: Normal CC: barraclough, ggaren, mark.lam, mhahnenberg, msaboff, oliver, sam
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Attachments:
Description Flags
WRONG PATCH
none
work in progress
none
sample profiling session
none
the patch oliver: review+

Filip Pizlo
Reported 2012-12-11 01:08:52 PST
The profiler currently records the bytecode at the time that it is first generated. But bytecode changes over time to incorporate profiling and inline caches. Currently the bytecode dumps already tell us: - the state of inline caches of heap accesses - the state of inline caches of calls And the bytecode dumps could easily also tell us: - slow path profiling data - value profiles One way to make this all useful is to enable the profiler to see the bytecode dumps at the time that the JITs were invoked.
Attachments
WRONG PATCH (1.60 KB, patch)
2012-12-11 01:11 PST, Filip Pizlo 		no flags
DetailsFormatted DiffDiff
work in progress (35.65 KB, patch)
2012-12-11 01:12 PST, Filip Pizlo 		no flags
DetailsFormatted DiffDiff
sample profiling session (27.55 KB, text/plain)
2012-12-11 14:23 PST, Filip Pizlo 		no flags
Details
the patch (60.73 KB, patch)
2012-12-11 14:34 PST, Filip Pizlo 		oliver: review+
DetailsFormatted DiffDiff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.
Filip Pizlo
Comment 1 2012-12-11 01:11:58 PST
Created attachment 178744 [details] WRONG PATCH
Filip Pizlo
Comment 2 2012-12-11 01:12:50 PST
Created attachment 178745 [details] work in progress
Filip Pizlo
Comment 3 2012-12-11 14:23:43 PST
Created attachment 178876 [details] sample profiling session This shows some of the changes that this patch makes. - You now see the instruction count in the full summary. - The full summary is now the default thing displayed when you run the tool (if you want the summary that just includes function names, source counts, and source, then use "s" or "summary") - New command, "profiling" or "p", which shows all of the profiling views that the JITs saw for each compilation that involved that code block. In this example I'm looking at a code block that gets inlined *a lot*. It's fun to see how the profiling "evolves" over time.
Filip Pizlo
Comment 4 2012-12-11 14:34:08 PST
Created attachment 178879 [details] the patch
Filip Pizlo
Comment 5 2012-12-11 16:22:55 PST
Landed in http://trac.webkit.org/changeset/137379
Note You need to log in before you can comment on or make changes to this bug.