Re: [PATCHSET 00/21] perf tools: Add support to accumulate hist periods (v9)

From: Arun Sharma
Date: Tue Apr 01 2014 - 03:36:24 EST


On 4/1/14, 12:58 PM, Namhyung Kim wrote:


gdb attributes 0x10370 to a different/known symbol.

(gdb) x /i 0x10370
0x10370 <get_cie_encoding+160>: cmp $0x4c,%dl

Is this known? Could this possibly be caused by stale histogram entries from
unmapped/remapped shared libs?

Possibly.

Anyway the addr which perf reported is a mapped address so that it's
pointless to use the addr directly - it's 7f1b0c963370 in fact.


Right - that's the address I'd use if the process in question is still running. But gdb <dso name> followed by relative addresses could still tell us what the right symbol was?

What was the exact command line though - did you use any filter
(--comms, --dsos, --symbols) or event modifiers? Those are another
possible culprits since map searching code touched by recent changes.

There were no other filters. The command used was just "perf top".


I'm not able to reproduce the problem on my machine. It'd be great if
you could bisect or let me know how to reproduce it easily.


I don't have a solid repro either. Involves building a binary, running "perf top" and waiting for a few mins until that warning popup appears.

Will try to git bisect and figure out potential culprits.

-Arun
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