Messages in this thread | | | Date | Wed, 13 Aug 2003 20:58:20 -0500 | From | Matt Mackall <> | Subject | Re: [PATCH] cryptoapi: Fix sleeping |
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On Wed, Aug 13, 2003 at 05:34:12PM -0700, Robert Love wrote: > On Wed, 2003-08-13 at 17:21, Jeff Garzik wrote: > > > Do you really want to schedule inside preempt_disable() ? > > in_atomic() includes a check for preempt_disable() ... that is actually > all it checks (the preempt_count). So this fix prevents that. > > This patch is interesting, though, because if right now we are > scheduling in the middle of per-CPU code there is a bug (regardless of > kernel preemption -- and with kernel preemption off, the in_atomic() > check might return false even though the code is accessing per-processor > data). > > So I think what we really want is to just never call this crypto_yield() > thing when in any sort of critical section, which includes any > per-processor data.
This is part of cryptoapi and given the large chunks of work you could potentially hand to it, it's probably a good idea for it to work this way. You hand it a long list of sg segments, it does the transform and reschedules if it thinks it's safe. But its test of when it was safe was not complete.
-- Matt Mackall : http://www.selenic.com : of or relating to the moon - 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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