Messages in this thread | | | Date | Tue, 9 Jan 2007 15:39:26 +0530 | From | Srivatsa Vaddagiri <> | Subject | Re: [PATCH] flush_cpu_workqueue: don't flush an empty ->worklist |
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On Tue, Jan 09, 2007 at 01:51:52AM -0800, Andrew Morton wrote: > > This thread makes absolutely -no- calls to try_to_freeze() in its lifetime. > > Looks like a bug to me. powerpc does appear to try to support the freezer. > > > 1. Does this mean that the thread can't be frozen? (lets say that the > > thread's PF_NOFREEZE is not set) > > yup. I'd expect the freeze_processes() call would fail if this thread is > running.
ok.
> > > AFAICS it can still be frozen by sending it a signal and have the signal > > delivery code call try_to_freeze() .. > > kernel threads don't take signals in the same manner as userspace. A > kernel thread needs to explicitly poll, via > > if (signal_pending(current)) > do_something()
Thanks for the education! I feel much better about the use of process freezer now ..
> > 2. If the thread can be frozen at any arbitrary point of its execution, then I > > dont see what prevents cpu_online_map from changing under the feet of rtasd > > thread, > > It cannot.
Excellent ..
I just hope the latency of freeze_processes() is tolerable ..
-- Regards, vatsa - 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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