On Wed, 2008-01-30 at 17:57 +0900, KOSAKI Motohiro wrote: > Hi Rik, Lee > > I found number of scan pages calculation bug. > > 1. wrong calculation order > > ap *= rotate_sum / (zone->recent_rotated_anon + 1); > > when recent_rotated_anon = 100 and recent_rotated_file = 0, > > rotate_sum / (zone->recent_rotated_anon + 1) > = 100 / 101 > = 0 > > at that time, ap become 0. > > 2. wrong fraction omission > > nr[l] = zone->nr_scan[l] * percent[file] / 100; > > when percent is very small, > nr[l] become 0. > > Test Result: > (1) $ ./hackbench 150 process 1000 > (2) # sync; echo 3 > /proc/sys/vm/drop_caches > $ dd if=tmp10G of=/dev/null > $ ./hackbench 150 process 1000 > > rvr-split-lru + revert patch of previous mail > (1) 83.014 > (2) 717.009 > > rvr-split-lru + revert patch of previous mail + below patch > (1) 61.965 > (2) 85.444 !! > > > Now, We got 1000% performance improvement against 2.6.24-rc8-mm1 :) > > > > - kosaki > > > Signed-off-by: KOSAKI Motohiro <[EMAIL PROTECTED]>
<snip> Kosaki-san: Rik is currently out on holiday and I've been traveling. Just getting back to rebasing to 24-rc8-mm1. Thank you for your efforts in testing and tracking down the regressions. I will add your fixes into my tree and try them out and let you know. Rik mentioned to me that he has a fix for the "get_scan_ratio()" calculation that is causing us to OOM kill prematurely--i.e., when we still have lots of swap space to evict swappable anon. I don't know if it's similar to what you have posted. Have to wait and see what he says. Meantime, we'll try your patches. Again, thank you. Regards, Lee -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
