On 05/08/2012 05:09 AM, Rik van Riel wrote: > On 04/26/2012 11:41 AM, KOSAKI Motohiro wrote: >> On Thu, Apr 26, 2012 at 10:26 AM, Richard Davies >> <richard.davies@xxxxxxxxxxxxxxxx> wrote: >>> Satoru Moriya wrote: >>>>> I have run into problems with heavy swapping with swappiness==0 and >>>>> was pointed to this thread ( >>>>> http://marc.info/?l=linux-mm&m=133522782307215 ) >>>> >>>> Did you test this patch with your workload? >>> >>> I haven't yet tested this patch. It takes a long time since these are >>> production machines, and the bug itself takes several weeks of >>> production >>> use to really show up. >>> >>> Rik van Riel has pointed out a lot of VM tweaks that he put into 3.4: >>> http://marc.info/?l=linux-mm&m=133536506926326 >>> >>> My intention is to reboot half of our machines into plain 3.4 once it is >>> out, and half onto 3.4 + your patch. >>> >>> Then we can compare behaviour. >>> >>> Will your patch apply cleanly on 3.4? >> >> Note. This patch doesn't solve your issue. This patch mean, >> when occuring very few swap io, it change to 0. But you said >> you are seeing eager swap io. As Dave already pointed out, your >> machine have buffer head issue. >> >> So, this thread is pointless. > > Running KVM guests directly off block devices results in a lot > of buffer cache. > > I suspect that this patch will in fact fix Richard's issue. > > The patch is small, fairly simple and looks like it will fix > people's problems. It also makes swappiness=0 behave the way > most people seem to imagine it would work. > > If it works for a few people (test results), I believe we > might as well merge it. > > Yes, for cgroups we may need additional logic, but we can > sort that out as we go along. > I agree Rik's opinion absolutely. -- Kind regards, Minchan Kim -- 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>