X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Documentation%2Fsysctl%2Fvm.txt;h=7cee90223d3a0624296b42d983d786b25462dc56;hb=46009c8bcd5d7c9fcbfc17d0455a471bea5be4d4;hp=a46c10fcddfcf17969d42fb472af306d9e9eab6f;hpb=99b3738fbf17208ac474420fa6b7e4b0c0c2b9ed;p=linux-2.6 diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index a46c10fcdd..7cee90223d 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -28,7 +28,8 @@ Currently, these files are in /proc/sys/vm: - block_dump - drop-caches - zone_reclaim_mode -- zone_reclaim_interval +- min_unmapped_ratio +- panic_on_oom ============================================================== @@ -166,15 +167,28 @@ 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. -================================================================ +============================================================= -zone_reclaim_interval: +min_unmapped_ratio: -The time allowed for off node allocations after zone reclaim -has failed to reclaim enough pages to allow a local allocation. +This is available only on NUMA kernels. -Time is set in seconds and set by default to 30 seconds. +A percentage of the file backed 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. -Reduce the interval if undesired off node allocations occur. However, too -frequent scans will have a negative impact onoff node allocation performance. +The default is 1 percent. + +============================================================= + +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.