]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
profiling: dynamically enable readprofile at runtime
authorDave Hansen <dave@linux.vnet.ibm.com>
Thu, 16 Oct 2008 05:01:46 +0000 (22:01 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 16 Oct 2008 18:21:31 +0000 (11:21 -0700)
commit22b8ce94708f7cdf0b04965c6f7443dfd374c35c
treee2d5b60e9b881cf251185b23c3853c8b3e52d42a
parent0c2d64fb6cae9aae480f6a46cfe79f8d7d48b59f
profiling: dynamically enable readprofile at runtime

Way too often, I have a machine that exhibits some kind of crappy
behavior.  The CPU looks wedged in the kernel or it is spending way too
much system time and I wonder what is responsible.

I try to run readprofile.  But, of course, Ubuntu doesn't enable it by
default.  Dang!

The reason we boot-time enable it is that it takes a big bufffer that we
generally can only bootmem alloc.  But, does it hurt to at least try and
runtime-alloc it?

To use:
echo 2 > /sys/kernel/profile

Then run readprofile like normal.

This should fix the compile issue with allmodconfig.  I've compile-tested
on a bunch more configs now including a few more architectures.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/ABI/testing/sysfs-profiling [new file with mode: 0644]
include/linux/profile.h
kernel/ksysfs.c
kernel/profile.c