On Mon, 2011-11-21 at 17:18 +0800, Wu Fengguang wrote: > plain text document attachment (readahead-tracer.patch) > This is very useful for verifying whether the algorithms are working > to our expectaions. > > Example output: > > # echo 1 > /debug/tracing/events/vfs/readahead/enable > # cp test-file /dev/null > # cat /debug/tracing/trace # trimmed output > readahead-initial(dev=0:15, ino=100177, req=0+2, ra=0+4-2, async=0) = 4 > readahead-subsequent(dev=0:15, ino=100177, req=2+2, ra=4+8-8, async=1) = 8 > readahead-subsequent(dev=0:15, ino=100177, req=4+2, ra=12+16-16, async=1) = 16 > readahead-subsequent(dev=0:15, ino=100177, req=12+2, ra=28+32-32, async=1) = 32 > readahead-subsequent(dev=0:15, ino=100177, req=28+2, ra=60+60-60, async=1) = 24 > readahead-subsequent(dev=0:15, ino=100177, req=60+2, ra=120+60-60, async=1) = 0 > > CC: Ingo Molnar <mingo@xxxxxxx> > CC: Jens Axboe <jens.axboe@xxxxxxxxxx> > CC: Steven Rostedt <rostedt@xxxxxxxxxxx> Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx> -- Steve > CC: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> > Acked-by: Rik van Riel <riel@xxxxxxxxxx> > Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>