Messages in this thread |  | | Date | Wed, 03 Jan 2001 16:59:52 +0100 | From | Daniel Phillips <> | Subject | Re: scheduling problem? |
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Mike Galbraith wrote: > > On Wed, 3 Jan 2001, Daniel Phillips wrote: > > > Mike Galbraith wrote: > > > Semaphore timed out during boot, leaving bdflush as zombie. > > > > Wait a sec, what do you mean by 'semaphore timed out'? These should > > wait patiently forever. > > IKD has a semaphore deadlock detector.
That was my tentative conclusion.
> Any place you take a semaphore > and have to wait longer than 5 seconds (what I had it set to because > with trace buffer set to 3000000 entries, it can only cover ~8 seconds > of disk [slowest] load), it triggers and freezes the trace buffer for > later use. It firing under load may not be of interest. (but it firing > looks to be very closly coupled to observed stalls with virgin source. > Linus fixes big stall and deadlock detector mostly shuts up. I fix a > smaller stall and it shuts up entirely.. for this workload)
But it's entirely legal for a semaphore to wait forever when used in the way I've used them, a producer/consumer pattern. You should be able to run happily (at least as happily as before) with the watchdog disabled.
This begs the question of what to do about the 99.99% of cases where the watchdog is a good thing to have. Shouldn't the watchdog just log the 'suspicious' event and continue?
-- Daniel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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