On Fri, Feb 19, 2010 at 3:59 AM, Anton Blanchard <an...@samba.org> wrote: > > I noticed /proc/sys/vm/zone_reclaim_mode was 0 on a ppc64 NUMA box. It gets > enabled via this: > > /* > * If another node is sufficiently far away then it is better > * to reclaim pages in a zone before going off node. > */ > if (distance > RECLAIM_DISTANCE) > zone_reclaim_mode = 1; > > Since we use the default value of 20 for REMOTE_DISTANCE and 20 for > RECLAIM_DISTANCE it never kicks in. > > The local to remote bandwidth ratios can be quite large on System p > machines so it makes sense for us to reclaim clean pagecache locally before > going off node. > > The patch below sets a smaller value for RECLAIM_DISTANCE and thus enables > zone reclaim. >
A reclaim distance of 10 implies a ratio of 1, that means we'll always do zone_reclaim() to free page cache and slab cache before moving on to another node? Balbir Singh. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
