On Wednesday 31 August 2011 08:26 PM, Dave Martin wrote:
On Thu, Aug 25, 2011 at 04:48:57PM -0500, Tom Gall wrote:
Hi all,
Say has anyone else run oprofile on recent builds on panda?
By recent I mean say anything since 11.07? Reason for asking is I'm seeing basically a very very small number of samples being recorded... as in there's no way this is right.
These days, I believe the separate oprofile backend for ARM has gone away, and oprofile is implemented using the perf backend anyway.
So, perhaps a more interesting question is: does perf work?
See whether this works:
apt-get install linux-linaro-tools-`uname -r` perf stat apt-get update # or something
I think there was an issue with a patch which enabled perf on omap4 but broke it on all other platforms. This patch is present in the linux-linaro-natty tree, but I can't see it in -oneiric. I think it may have been dropped / backed out from the oneiric tree because of the problems it caused:
In linux-linaro-natty/master: commit 457520e3fbce80812c6901c226ec242fdb906c63 (arm: pmu: support pmu/perf on OMAP4)
The perf patch was dropped from linux-linaro-2.6.39 onwards as it apparently caused Panda boot hang (https://bugs.launchpad.net/linux-linaro/+bug/802693).
Mark Rutland posted a patch to fix the introduced problem -- search the linaro-dev archives for [PATCH] Fix NULL-dereference introduced by OMAP4 PMU patch
...however, I don't know whether or not this is still relevant.
If perf works but oprofile doesn't, that's a separate problem and should be investigated. You might want to consider switching to perf anyway though -- in my experience it's less problem-prone than using oprofile.
Cheers ---Dave
Regards, Avik