David Teigland wrote: > On Wed, Sep 26, 2007 at 08:18:55AM +0100, Patrick Caulfield wrote: >> David Teigland wrote: >>> Call schedule() in a bunch of places where the recovery code loops >>> through lists of locks. The theory is that these lists become so >>> long that looping through them triggers the softlockup watchdog. >>> (usually on ia64, doesn't seem to happen often on other arch's). >>> >>> Signed-off-by: David Teigland <[EMAIL PROTECTED]> >> >> I think we're encouraged to use cond_resched() instead these days. It has the >> same effect but doesn't force a schedule if there is nothing else to run. > > OK, I'd like to try to do cond_resched() instead, how certain are we that > it's just as effective in avoiding the softlockup watchdog? Testing it is > going to be difficult since it's largely unreproducable outside of some > single cpu ia64 machines in the qe dept...
I can't see it making any real difference. If there is nothing to schedule then the process will continue. With cond_resched() it continues cheaply, with schedule() it will re-enter the scheduler and /then/ get rescheduled. If anything it will help because there's less time spent in the schedule I suspect (though I doubt it's measurable) -- Patrick
