Re: [PATCH v4 1/5] rwsem: check the lock before cpmxchg in down_write_trylock

[Alex Shi]

The following line should be added head of commit log on patches 1~4. :)

From: Alex Shi <alex.shi@xxxxxxxxx>


> Cmpxchg will cause the cacheline bouning when do the value checking,
> that cause scalability issue in a large machine (like a 80 core box).
> 
> So a lock pre-read can relief this contention.
> 
> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>


-- 
Thanks
    Alex
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