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On Sun, Nov 04 2001, Andrew Morton wrote: > Jens Axboe wrote: > > > > On Sun, Nov 04 2001, Andrew Morton wrote: > > > The meaning of the parameter to elvtune is a complete mystery, and the > > > code is uncommented crud (tautology). So I just used -r20000 -w20000. > > > > It's the number of sectors that are allowed to pass a request on the > > queue, because of merges or inserts before that particular request. So > > you want lower than that probably, and you want READ latency to be > > smaller than WRITE latency too. The default I set is 8192/16384 iirc, so > > go lower than this -- -r512 -w1024 or even lower just to check the > > results. > > Right, thanks. With the ialloc.c one-liner I didn't touch > elvtune. Defaults seem fine. > > It should the number of requests which are allowed to pass a > request, not the number of sectors! > > Well, you know what I mean: Make it > > 1 + nr_sectors_in_request / 1000 That has been tried, performance and latency wasn't good. But yes that is what we are really looking to account, the number of seeks. Approximately. -- Jens Axboe - 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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