Messages in this thread | | | From | Marr <> | Subject | Re: Readahead value 128K? (was Re: Drastic Slowdown of 'fseek()' Calls From 2.4 to 2.6 -- VMM Change?) | Date | Mon, 13 Mar 2006 15:00:26 -0500 |
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On Monday 13 March 2006 9:41am, Mark Lord wrote: > Marr wrote: > > Anyway, not that it really matters, but I re-did the testing with '-a0' > > and it didn't help one iota. The 2.6.13 kernel on ReiserFS (without using > > 'nolargeio=1' as a mount option) still takes about 4m35s to fseek 200,000 > > times on that 4MB file, even with 'hdparm -a0 /dev/hda' in effect. > > Does it make a difference when done on the filesystem *partition* > rather than the base drive? At one time, this mattered, and it may > still work that way today. > > Eg. hdparm -a0 /dev/hda3 rather than hdparm -a0 /dev/hda > > ??
Unfortunately, it makes no difference. That is, after successfully setting '-a0' on the partition in question (instead of the whole HDD device itself), the 200,000 random 'fseek()' calls still take about 4m35s on ReiserFS (without using 'nolargeio=1' as a mount option) under kernel 2.6.13.
P.S. I've CC:ed you and the others on my reply to Al Boldi's request for the 'hdparm -I /dev/hda' information, in case it helps at all.
Thanks for your inputs, Mark -- much appreciated!
*** Please CC: me on replies -- I'm not subscribed.
Regards, Bill Marr - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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