Re: all mutexes -> read-write locks?

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From
Ed Schouten <ed@80386.nl>
Date
1 Jun 2008 21:58:01
Subject
Re: all mutexes -> read-write locks?
Message-ID
20080601215759.GN64397@hoeg.nl

In reply to
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Hello Julian,

* Julian Elischer <julian@elischer.org> wrote:
> it has been mentioned several times that through the evolution of the
> locking primitives it has come to be that mutexes and exclusively
> acquired reader-writer locks are almost the same in terms of overhead
> and that it might be a good move to define all mutexes to be
> actually just that.
>
> this would allow people to slowly go through the system, catching low
> hanging fruit by converting some of the mutex operations to reader
> acquisitions wherever a writer is not required, thus reducing general
> system contention.
>
> Is there any thought on this? Last I heard jhb had confirmed that it
> was feasible..

If this is going to be done, could we have mtx_* macro's pointing to the
proper read/write ops? I know, it's just names, but I think most novice
FreeBSD kernel hackers will almost instantaneously figure out what 'mtx'
stands for.

Why not make read/write locking a fundamental part of 'mtx' itself, if
it doesn't introduce much overhead?

--
Ed Schouten <ed@80386.nl>
WWW: http://80386.nl/


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