Messages in this thread | | | Date | Sat, 26 Jun 2004 09:44:44 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH] Fix the cpumask rewrite |
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On Sat, 26 Jun 2004, Linus Torvalds wrote: > > Why not? The thing is, the bitmap operators are supposed to work on > volatile data, ie people are literally using them for things like > > while (test_bit(TASKLET_STATE_SCHED, &t->state));
Ahh. That one is part of a "do while ()" loop, and grep mis-identifies it. So parisc gets it right, because the whole loop is
do yield(); while (test_bit(TASKLET_STATE_SCHED, &t->state));
so at least the compiler didn't get to optimize it away.
Hopefully we don't have any other busy loops either - even if it is a busy loop, we should have a "cpu_relax()" or something there just to keep power levels down, and that should also tell the compiler not to do anything silly. But the conceptual point stands.
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