Re: Do we need so many hint bits?

On Mon, 2012-11-19 at 23:50 +0530, Atri Sharma wrote:

> Sorry If I am being a bit naive, but shouldnt a simple mutex work in
> the case when a process wants to change the VM bit in cache?
> 
> Mutex would be cheaper than locks.
> 
I thought mutexes are locks?

The point is to avoid taking new locks (or mutexes) during a read of the
VM bit, because there is concern that it could cause contention. If we
lock the entire VM page, that represents many, many data pages, so it's
worrisome.

Regards,Jeff Davis