Messages in this thread | | | From | Heinz Mauelshagen <> | Subject | Re: [patch] dynamic buffer cache hash table size | Date | Mon, 25 Jan 1999 20:34:56 MET |
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> > Hi, > > On Sat, 23 Jan 1999 0:00:23 MET, Heinz Mauelshagen > <mauelsha@ez-darmstadt.telekom.de> said: > > > Have to do that test run later, but have a look at the already existing > > one below. > > > Ingo Molnar asked me just today for a profile. > > Most of the time is wasted in sync_buffers. >
On Mon, 25 Jan 1999 16:55:50 GMT, Stephen C. Tweedie <sct@redhat.com> answered: > > I am not surprised. Currently we have no way to flush completed > writeback buffers off the LOCKED list and back onto the CLEAN list. > sync() is therefore wandering over clean buffers all the time. > > Could you try the following patch (against 2.2.0-pre9)? It allows both > sync and bdflush to refile such completed buffers back to the CLEAN > list. >
Hi Stephen.
Your patch is _great_. It improves performance a lot.
Without it my test programs needed up to more than 30s with 120M buffermem and up to 45s with 200M.
With your patch they need 1.5s/2.5s!!! To compare: with little buffermem after reboot they need 0.3s.
This is a _must_ for 2.2.0!
Best regards, Heinz --
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Systemmanagement Entwicklungsbereich 2 Deutsche Telekom AG Entwicklungszentrum Darmstadt Heinz Mauelshagen Otto-Roehm-Strasse 71c Postfach 10 05 41 mge@ez-darmstadt.telekom.de 64205 Darmstadt Germany +49 6151 886-425 FAX-386 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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