- block_dump
- drop-caches
- zone_reclaim_mode
-- min_unmapped_ratio
-- min_slab_ratio
-- panic_on_oom
+- zone_reclaim_interval
==============================================================
1 = Zone reclaim on
2 = Zone reclaim writes dirty pages out
4 = Zone reclaim swaps pages
+8 = Also do a global slab reclaim pass
zone_reclaim_mode is set during bootup to 1 if it is determined that pages
from remote zones will cause a measurable performance reduction. The
node unless explicitly overridden by memory policies or cpuset
configurations.
-=============================================================
+It may be advisable to allow slab reclaim if the system makes heavy
+use of files and builds up large slab caches. However, the slab
+shrink operation is global, may take a long time and free slabs
+in all nodes of the system.
-min_unmapped_ratio:
+================================================================
-This is available only on NUMA kernels.
+zone_reclaim_interval:
-A percentage of the total pages in each zone. Zone reclaim will only
-occur if more than this percentage of pages are file backed and unmapped.
-This is to insure that a minimal amount of local pages is still available for
-file I/O even if the node is overallocated.
+The time allowed for off node allocations after zone reclaim
+has failed to reclaim enough pages to allow a local allocation.
-The default is 1 percent.
+Time is set in seconds and set by default to 30 seconds.
-=============================================================
-
-min_slab_ratio:
-
-This is available only on NUMA kernels.
-
-A percentage of the total pages in each zone. On Zone reclaim
-(fallback from the local zone occurs) slabs will be reclaimed if more
-than this percentage of pages in a zone are reclaimable slab pages.
-This insures that the slab growth stays under control even in NUMA
-systems that rarely perform global reclaim.
-
-The default is 5 percent.
-
-Note that slab reclaim is triggered in a per zone / node fashion.
-The process of reclaiming slab memory is currently not node specific
-and may not be fast.
-
-=============================================================
-
-panic_on_oom
-
-This enables or disables panic on out-of-memory feature. If this is set to 1,
-the kernel panics when out-of-memory happens. If this is set to 0, the kernel
-will kill some rogue process, called oom_killer. Usually, oom_killer can kill
-rogue processes and system will survive. If you want to panic the system
-rather than killing rogue processes, set this to 1.
-
-The default value is 0.
+Reduce the interval if undesired off node allocations occur. However, too
+frequent scans will have a negative impact onoff node allocation performance.
git://git.onelab.eu / linux-2.6.git / blobdiff