Messages in this thread | | | Date | Thu, 2 Dec 2004 14:48:02 +0100 | From | Jens Axboe <> | Subject | Re: Time sliced CFQ io scheduler |
| |
Hi,
One more test case, while the box is booted... This just demonstrates a process doing a file write (bs=64k) with a competing process doing a file read (bs=64k) at the same time, again capped at 30sec.
deadline: Reader: 2520KiB/sec (max_lat=45msec) Writer: 1258KiB/sec (max_lat=85msec)
as: Reader: 27985KiB/sec (max_lat=34msec) Writer: 64KiB/sec (max_lat=1042msec)
cfq: Reader: 12703KiB/sec (max_lat=108msec) Writer: 9743KiB/sec (max_lat=89msec)
If you look at vmstat while running these tests, cfq and deadline give equal bandwidth for the reader and writer all the time, while as basically doesn't give anything to the writer (a single block per second only). Nick, is the write batching broken or something?
-- 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/
| |