19 Jul
2004
19 Jul
'04
10:19 a.m.
* Andrea Arcangeli <andrea(a)suse.de> wrote:
As Ingo basically showed (and I agree), all current
might_sleep seems
suitable to be converted to cond_resched. I checked all them and
there's none that seems to be called in a loop for no good reason. the
ones in the semaphore are quite nice too since it's better to schedule
right before taking the semaphore than after getting it. The one in
the semaphore and in the copy-user are the only place where preempt
seems to be lower overhead but in most other places a spinlock is
being taken very near to the cond_resched.
yes. Btw., i'm not sure whether you've noticed but last week i've also
created a 'clean' variant of the patch. The latest version against -mm
is:
http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-clean-2.6.7-mm…
this one doesnt have any of the debugging/development helpers and
switches. I have still made it a .config option. Note how minimal the
patch became this way.
Ingo