lkml.org 
[lkml]   [2012]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCHv2 00/14] perf diff: Factor diff command
> > Some minor issues I ran into (but no show stoppers):
> > - The error messages for bad -c expressions could be better
> > - I found the requirement for no space after -c unintuitive.
>
> I'll see to that >
> > - It would be nice to have support for doing the bucketizing per line
> > instead of per function. With a large function and/or inlining
> > it's sometimes hard to identify the actual problem
> > Acme recently added this for perf report.
>
> hm, I missed this one.. hopefully it should be no problem to add it

Here's more issues I found (again no show stopper):

For example you have a spinlock problem with different spinlock callers
that you want to handle. Since the spinlocks are own functions which
are mixed together cannot be easily ratiod.

This is probably a bit hard to handle, but one way would be to use
a variant of the inclusive reporting Arun recently submitted.
Define groups of callers that have a combined cost including all
callees. Use this as the diff unit.

I really liked the oprofile behaviour of attributing lock costs
to the caller by default. With that it would just work.

The other problem I ran into is that perf archive doesn't seem to
work very well with kernels, so it's hard to move profiles from
different kernels around to diff them (e.g. for a performance regression)
One way around this would be options to diff to specify the vmlinux etc.
manually

-Andi


\
 
 \ /
  Last update: 2012-10-02 19:01    [W:0.158 / U:0.608 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site