On Tue, 27 Dec 2011 13:56:58 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > Hmm, if I understand correctly, > > - dd's speed down is caused by kswapd's cpu consumption. > - kswapd's cpu consumption is enlarged by shrink_slab() (by perf) > - kswapd can't stop because NORMAL zone is small. > - memory reclaim speed is enough because dd can't get enough cpu. > > I wonder reducing to call shrink_slab() may be a help but I'm not sure > where lock conention comes from... Nikolay, it sounds as if this problem has only recently started happening? Was 3.1 OK? If so, we should work out what we did post-3.1 to cause this. -- 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>