[PATCH 0/4] ipc/sem.c: Bug fixes, regression fixes, v3

[Manfred Spraul]

I've split my patch into 4 parts:
- 1: Fix-missing-wakeups-in-do_smart_update
- 2: seperate-wait-for-zero-and-alter-tasks
- 3: Always-use-only-one-queue-for-alter-operations
- 4: Rename-try_atomic_semop-to-perform_atomic

Linus:
- Patch 1 should be merged immediately: It fixes bugs,
  the current code misses wakeups.

- Patch 2 and 3 restore the behavior of linux <=3.0.9.
  I would propose that they are merged, too: I can't rule out that
  changing the priority of the wakeups breaks user space apps.

- Patch 4 is trivial, no code changes at all.
  If 2+3 are merged, then 4 should be merged, too.

I have tested patch 1 seperately and 1+2+3+4:
With patch 1 applied, there are no more missed wakeups.

With all 4 applied, linux-3.0.10-rc1 behaves as linux <=3.0.9.

With regards to the scalability, I do not expect any degradation:
Operations on seperate semaphores in an array remain parallelized.

Apps that use lots of wait-for-zero semop are probably even faster,
because the wait-for-zero ops are now only scanned if a semval is 0.

--
	Manfred
--
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/