On 05/26/2013 05:08 AM, Manfred Spraul wrote:
do_smart_update_queue() is called when an operation
(semop, semctl(SETVAL), semctl(SETALL), ...) modified the array.
It must check which of the sleeping tasks can proceed.
do_smart_update_queue() missed a few wakeups:
- if a sleeping complex op was completed, then all per-semaphore queues
must be scanned - not only those that were modified by *sops
- if a sleeping simple op proceeded, then the global queue
must be scanned again
And:
- the test for "|sops == NULL) before scanning the global
queue is not required: If the global queue is empty, then
it doesn't need to be scanned - regardless of the reason
for calling do_smart_update_queue()
The patch is not optimized, i.e. even completing a wait-for-zero
operation causes a rescan. This is done to keep the patch as simple as
possible.
Avoiding unnecessary scans is implemented in the following patches.
Signed-off-by: Manfred Spraul <manf...@colorfullife.com>
Very much not optimized, but we need to fix the regression.
Acked-by: Rik van Riel <r...@redhat.com>
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