Re: 2.6.35-rc3 deadlocks on semaphore operations

From: Manfred Spraul
Date: Sat Jun 19 2010 - 10:43:21 EST


Hello Christoph,

On 06/18/2010 04:56 PM, Christoph Lameter wrote:
One important fact that I forgot to mention: This is on a dual quad core
dell box (8 hardware threads) with CONCURRENCY_LEVEL set to 9.

- Which version of make do you use? That would be one suspect that might use semop().

- If I run make -j5 bzImage, then no semaphore arrays are used.
Could you try to figure out which executable is doing the 'semop()' call?
Or: what's the output of ps xawwwww_

- You are able to attach to the sleeping process with strace - and the process continues to wait.
I think this means that the semaphore counter is really 0: Somehow, we leak semaphore values.

But I did not change this code, what was changed was the wake-up code.

--
Manfred
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