Messages in this thread | | | Date | Tue, 13 Jul 2004 16:06:28 -0700 | From | Andrew Morton <> | Subject | Re: [linux-audio-dev] Re: [announce] [patch] Voluntary Kernel Preemption Patch |
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Andrea Arcangeli <andrea@suse.de> wrote: > > What I'm doing is basically to replace all might_sleep with cond_resched
I cannot see a lot of point in that. They are semantically different things and should look different in the source.
And it's currently OK to add a might_sleep() to (say) an inline path which is expended a zillion times because we know it'll go away for production builds. If those things become cond_resched() calls instead, the code increase will be permanent.
> cond_resched_lock is another story of course.
cond_resched_lock() doesn't work on SMP. I'll probably be removing it in favour of unconditionally dropping the lock every N times around the loop, to allow the other CPU (the one with need_resched() true) to get in there and take it.
And please let me repeat: preemption is the way in which we wish to provide low-latency. At this time, patches which sprinkle cond_resched() all over the place are unwelcome. After 2.7 forks we can look at it again.
I've yet to go through Arjan's patch - I suspect a lot of it is not needed. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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