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SubjectRe: [PATCH] perf jvmti: remove redundant jitdump line table entries
On Tue, May 26, 2020 at 10:40 PM Nick Gasson <> wrote:
> On 05/27/20 13:03 PM, Ian Rogers wrote:
> >
> > Great result, thanks! I note there is a lack of symbolization when
> > benchmarking a few Java applications. I'll try to see if there's a
> > sensible resolution for those.
> >
> I noticed it loses information when the Hotspot code cache is
> resized. I've been working around that by setting
> -XX:InitialCodeCacheSize and -XX:ReservedCodeCacheSize to large
> values. Does this help in your case?

Thanks, I tried and also with Steve's patch:

Trying something very basic like just the -version command with compile only:
/tmp/perf/perf record -k 1 -e cycles:u -F 6500 -o /tmp/ java
-agentpath:/tmp/perf/ -XX:+PreserveFramePointer
-XX:InitialCodeCacheSize=2G -XX:ReservedCodeCacheSize=2G
-XX:CompileOnly=1 -version
/tmp/perf/perf inject -i /tmp/ -o /tmp/ -j
/tmp/perf/perf report -i /tmp/

I don't see any of the JDK classes but 35 unknown symbols out of 272.
The JDK classes are stripped to some degree iirc, but we should be
able to give a symbol name as we don't care about local variables and

This isn't a blocker for this patch and perhaps I'm special in seeing
this problem. Thanks,

> >
> > It'd be better to make this into two patches. Also on acme's perf/core
> > branch if possible:
> >
> OK sure, I'll do that.
> --
> Nick

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