Messages in this thread | | | Date | Thu, 29 Sep 2005 17:25:41 +0100 | From | Paulo Marques <> | Subject | Re: [PATCH] fix TASK_STOPPED vs TASK_NONINTERACTIVE interaction |
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Linus Torvalds wrote: > > On Thu, 29 Sep 2005, Oleg Nesterov wrote: > >>[...] >>However, TASK_NONINTERACTIVE > TASK_STOPPED, so this loop will not >>count TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE threads. > > [...] > Using ">" for task states is wrong. It's a bitmask, and if you want to > check multiple states, then we should just do so with > > if (t->state & (TASK_xxx | TASK_yyy | ...)) > > Oh, well. The inequality comparisons are shorter, and historical, so I > guess it's debatable whether we should remove them all.
I did a quick grep through 2.6.14-rc2 to see how many "them all" were, and the only two places I could find, where a inequality operator was being used on a task state, were this one in kernel/signal.c and another in kernel/exit.c:
./kernel/exit.c:1194: unlikely(p->state > TASK_STOPPED)
So maybe it is not so bad to just change these to a bit mask and disallow inequality comparisons in the future, if you guys feel that is the way to go...
-- Paulo Marques - www.grupopie.com
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