tree 78c2638ac583cc57165ee1393ebbbbbe367f46fb
parent cc4ea79588e688ea9b1161650979a194dd709169
author Ken Chen <kenchen@google.com> 1192735976 +0200
committer Ingo Molnar <mingo@elte.hu> 1192735976 +0200

sched: reduce schedstat variable overhead a bit

schedstat is useful in investigating CPU scheduler behavior.  Ideally,
I think it is beneficial to have it on all the time.  However, the
cost of turning it on in production system is quite high, largely due
to number of events it collects and also due to its large memory
footprint.

Most of the fields probably don't need to be full 64-bit on 64-bit
arch.  Rolling over 4 billion events will most like take a long time
and user space tool can be made to accommodate that.  I'm proposing
kernel to cut back most of variable width on 64-bit system.  (note,
the following patch doesn't affect 32-bit system).

Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>