Messages in this thread | | | Date | Wed, 31 Oct 2012 20:41:35 +0100 | From | Oleg Nesterov <> | Subject | [PATCH 0/1] percpu_rw_semaphore: reimplement to not block the readers unnecessarily |
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On 10/30, Oleg Nesterov wrote: > > So. down_write/up_right does msleep() and it needs to call > synchronize_sched() 3 times. > > This looks too much. It is not that I am worried about the writers, > the problem is that the new readers are blocked completely while the > writer sleeps in msleep/synchronize_sched. > > Paul, Mikulas, et al. Could you please look at the new implementation > below? Completely untested/uncompiled, just for discussion.
I tried to test it, seems to work...
But. I guess the only valid test is: pass the review from Paul/Peter.
Todo: - add the lockdep annotations
- we can speedup the down_write-right-aftet-up_write case
What do you all think?
Oleg.
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