Messages in this thread | | | Date | Tue, 30 Dec 2003 05:27:04 -0500 (EST) | From | Thomas Molina <> | Subject | Re: 2.6.0 performance problems |
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On Mon, 29 Dec 2003, William Lee Irwin III wrote:
> On Tue, 2003-12-30 at 00:58, Thomas Molina wrote: > >> It certainly looks like DMA is enabled. Under 2.4 I get: > >> [root@lap root]# hdparm /dev/hda > [...] > >> readahead = 8 (on) > [...] > >> Under 2.6 I get: > >> [root@lap root]# hdparm /dev/hda > [...] > >> readahead = 256 (on) > > On Tue, Dec 30, 2003 at 01:14:45AM +0200, Martin Schlemmer wrote: > > Increase your readahead: > > # hdparm -a 8192 /dev/hda > > BTW: As we really do get this question a _lot_ of times, why > > don't the ide layer automatically set a higher readahead > > if there is enough cache on the drive or something? > > Could you try lowering 2.6's readahead to 2.4's levels in order to rule > out readahead-induced thrashing?
I thought I had already sent that. The timings for readahead of 8 was:
real 25m39.653s user 0m37.594s sys 0m55.454s
Increasing readahead in 2.6 to 8192 likewise doesn't help. - 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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