Re: Anomalous performance increase from mutex profiling
"Surer Dink" <[email protected]>
| Newsgroups | gmane.os.freebsd.devel.smp |
|---|---|
| Message-ID | <[email protected]> |
On 4/17/06, Kris Kennaway <[email protected]> wrote: > On Mon, Apr 17, 2006 at 03:54:07AM -0400, Surer Dink wrote: > > Please excuse if this is a stupid question - but might using MCS or > > QOLB locks in this situation be useful? > > What are they? Mellor-Crummy Scott: http://www.cs.rochester.edu/u/scott/papers/1991_ASPLOS_sync.pdf An overview comparing various possible optimizations for a few lock types, including MCS and QOLB: ftp://ftp.cs.utexas.edu/pub/dburger/papers/ISCA97_qolb.pdf I believe the QOLB proposal only suggested hardware modificaition for performance improvement, but could be implemented entirely in software - the overheads are high, but offer substantial performance benefit in high contention situations. MCS is based on QOSB, however fully implemented in software. There is also a proposal for changing lock to MCS dynamically, however I have not read it: ftp://ftp.cag.lcs.mit.edu/pub/papers/pdf/reactive.pdf _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-smp To unsubscribe, send any mail to "[email protected]"