Re: tasks getting stuck on mmap_sem?

From: David Miller
Date: Tue Aug 17 2010 - 03:22:49 EST


From: Dimitris Michailidis <dm@xxxxxxxxxxx>
Date: Mon, 16 Aug 2010 22:22:04 -0700

> This may be similar to the problems IA-64 had last week as a result of
> the rwsem changes, eg see commit
> 01d69a82e1d3c938da16bf55aab000672243aa24. I see
> arch/sparc/include/asm/atomic_64.h uses ints with atomic64_t, which
> was a problem for IA-64. Just guessing.

Well, the return types for the atomic64 routines were wrong and I
fixed that.

But our rwsem implementation on sparc64 uses a 32-bit counter so that
couldn't be the issue. And indeed I still get the problem of tasks
being stuck on rwsems even after the atomic64 return types are fixed.

But I bet that rwsem commit 424acaaeb3a3932d64a9b4bd59df6cf72c22d8f3
introduced some kind of problem in another manner. I'll try to dig
some more.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/