On Tue, 18 Jan 2011 18:38:42 -0800 (PST) David Rientjes <rientjes@xxxxxxxxxx> wrote: > On Wed, 19 Jan 2011, KAMEZAWA Hiroyuki wrote: > > > > so something like per-memcg min_wmark which also needs to be reserved upfront? > > > > > > > I think the variable name 'min_free_kbytes' is the source of confusion... > > It's just a watermark to trigger background reclaim. It's not reservation. > > > > min_free_kbytes alters the min watermark of zones, meaning it can increase > or decrease the amount of memory that is reserved for GFP_ATOMIC > allocations, those in irq context, etc. Since oom killed tasks don't > allocate from any watermark, it also can increase or decrease the amount > of memory available to oom killed tasks. In that case, it _is_ a > reservation of memory. > I know. THIS PATCH's min_free_kbytes is not the same to ZONE's one. It's just a trigger. This patch's one is not used to limit charge() or for handling gfp_mask. (We can assume it's always GFP_HIGHUSER_MOVABLE or GFP_USER in some cases.) So, I wrote the name of 'min_free_kbytes' in _this_ patch is a source of confusion. I don't recommend to use such name in _this_ patch. Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>