Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 24 Nov 2007 23:12:36 -0800
From:      Darren Reed <darrenr@freebsd.org>
To:        Stephan Uphoff <ups@FreeBSD.org>
Cc:        cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org
Subject:   Re: cvs commit: src/share/man/man9 locking.9 rmlock.9 src/sys/conf files src/sys/kern kern_rmlock.c subr_lock.c subr_pcpu.c         subr_smp.c src/sys/sys _rmlock.h lock.h pcpu.h rmlock.h smp.h
Message-ID:  <47492064.7080108@freebsd.org>
In-Reply-To: <200711081447.lA8EltXO052057@repoman.freebsd.org>
References:  <200711081447.lA8EltXO052057@repoman.freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
Stephan Uphoff wrote:
> ups         2007-11-08 14:47:55 UTC
>
>   FreeBSD src repository
>
>   Modified files:
>     share/man/man9       locking.9 
>     sys/conf             files 
>     sys/kern             subr_lock.c subr_pcpu.c subr_smp.c 
>     sys/sys              lock.h pcpu.h smp.h 
>   Added files:
>     share/man/man9       rmlock.9 
>     sys/kern             kern_rmlock.c 
>     sys/sys              _rmlock.h rmlock.h 
>   Log:
>   Initial checkin for rmlock (read mostly lock) a multi reader single writer
>   lock optimized for almost exclusive reader access. (see also rmlock.9)
>   

Is there a white paper or other documentation around somewhere that
discusses the benefits/tradeoffs with using rmlock vs rwlock?

For example, how long can a write be delayed if there are lots of reads
being executed?  What sort of performance penalty does the write
suffer as a consequence of this vs rwlock, if any?

At what percentage of read vs write operations does it become better
to use rmlock vs rwlock?

Cheers,
Darren




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?47492064.7080108>