Apparently mmap overrules the fadvise functionality. When compiled on 2.4.32 w/ --disable-mmap, I get this:
denver ~ # time ./rrdtool fetch test.rrd AVERAGE ERROR: setting POSIX_FADV_RANDOM on 'test.rrd': Success real 0m0.016s user 0m0.010s sys 0m0.000s Not surprising, since posix_fadvise() isn't supported on 2.4.X. Not sure is that's considered a regression, or if --disable-mmap should be considered unsupported on 2.4.X -D > -----Original Message----- > From: Dylan Vanderhoof > Sent: Friday, June 15, 2007 12:32 PM > To: Bernhard Fischer > Cc: [email protected] > Subject: Re: [rrd-developers] rrdtool 1.3 cairo switch is done > > > I figured that's why it wasn't the default, but removing it had no > effect on rrdtool performance, I was just playing with options. > > I'm still seeing approximatly half the performance from trunk > than I am > 1.2.23 + fadvise. (For fetch. graph is about 1/3 the speed > with trunk) > I'll without mmap when I get a chance to see if that's part of the > issue. > > (FWIW, this is on linux 2.4.32, I haven't had a chance to test it on a > 2.6.X server yet) > > -D > > > -----Original Message----- > > From: Bernhard Fischer [mailto:[EMAIL PROTECTED] > > Sent: Friday, June 15, 2007 12:25 PM > > To: Dylan Vanderhoof > > Cc: [email protected] > > Subject: Re: [rrd-developers] rrdtool 1.3 cairo switch is done > > > > > > On Fri, Jun 15, 2007 at 10:50:24AM -0700, Dylan Vanderhoof wrote: > > >Tried this on my test server. Generated 515 graphs of ~30 > days each. > > >Trunk functions fine and the graphs look good, but its > substantially > > >slower than 1.2.23 w/ the fadvise patch. (trunk compiled > > with mmap and > > >directio) > > > > no. Don't use directio (unless all your rrd are on a RAM backed > > filesystem)! > > > > _______________________________________________ > rrd-developers mailing list > [email protected] > https://lists.oetiker.ch/cgi-bin/listinfo/rrd-developers > _______________________________________________ rrd-developers mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-developers
