Re: [PATCH] Fix behavior and documentation for '--threshold' option

On Thu, 2014-08-28 at 13:06 -0500, Maynard Johnson wrote:
> Fix behavior and documentation for '--threshold' option
> 
> A user reported some issues with how the opreport and opannotate
> '--threshold' option was working. He was using operf to collect
> a profile using mulitiple events (PM_CMPLU_STALL_REJECT_LHS and
> PM_MRK_ST_FWD). For a particular symbol in his profile data, he
> had 0% for PM_CMPLU_STALL_REJECT_LHS and 12% for PM_MRK_ST_FWD.
> But when he ran 'opannotate --assembly -t 1', he was surprised to
> see that the function in question was not in the output at all,
> even though the ratio of samples for the PM_CMPLU_STALL_REJECT_LHS
> was well above the 1% threshold.

> The events are stored in alphabetical order in a C++ set. When
> applying the threshold level against a symbol, the code was only
> looking at the ratio of samples for the first event in the set
> (PM_CMPLU_STALL_REJECT_LHS, in this case). This is not the intended
> behavior (IMHO), so this patch looks at all ratios for every event
> and will only filter out the sample data for a given symbol if none
> of the events meets the threshold.
> 
> This issue applies to opreport as well, and the same fix works for
> both opreport and 'opannotate --assembly'.
> 

I tested the new code with operf and opannotate and verified the
results. As requested I now see functions (symbols) from both events
with a --threshold of 1

> On the other hand, 'opannotate --source' applies the threshold to
> a given source file (contrary to the man page). The same problem
> exists there, where annotation for a given source file was not displayed
> if the ratio of samples for the first event in the set did not meet the
> specified threshold. This patch fixes that problem as well.



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