Re: [PATCH 1/2] rwsem: add rwsem_is_contended V3

2013-09-26 Thread Ingo Molnar
* Josef Bacik wrote: > Btrfs needs a simple way to know if it needs to let go of it's read lock on a > rwsem. Introduce rwsem_is_contended to check to see if there are any waiters > on > this rwsem currently. This is just a hueristic, it is meant to be light and > not > 100% accurate and cal

[PATCH 1/2] rwsem: add rwsem_is_contended V3

2013-09-26 Thread Josef Bacik
Btrfs needs a simple way to know if it needs to let go of it's read lock on a rwsem. Introduce rwsem_is_contended to check to see if there are any waiters on this rwsem currently. This is just a hueristic, it is meant to be light and not 100% accurate and called by somebody already holding on to