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| author | Jiri Kosina <jkosina@suse.cz> | 2010-06-16 20:08:13 +0400 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2010-06-16 20:08:13 +0400 |
| commit | f1bbbb6912662b9f6070c5bfc4ca9eb1f06a9d5b (patch) | |
| tree | c2c130a74be25b0b2dff992e1a195e2728bdaadd /Documentation/sysctl/vm.txt | |
| parent | fd0961ff67727482bb20ca7e8ea97b83e9de2ddb (diff) | |
| parent | 7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff) | |
| download | linux-f1bbbb6912662b9f6070c5bfc4ca9eb1f06a9d5b.tar.xz | |
Merge branch 'master' into for-next
Diffstat (limited to 'Documentation/sysctl/vm.txt')
| -rw-r--r-- | Documentation/sysctl/vm.txt | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 6c7d18c53f84..5fdbb612aeb8 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -19,6 +19,7 @@ files can be found in mm/swap.c. Currently, these files are in /proc/sys/vm: - block_dump +- compact_memory - dirty_background_bytes - dirty_background_ratio - dirty_bytes @@ -26,6 +27,7 @@ Currently, these files are in /proc/sys/vm: - dirty_ratio - dirty_writeback_centisecs - drop_caches +- extfrag_threshold - hugepages_treat_as_movable - hugetlb_shm_group - laptop_mode @@ -64,6 +66,15 @@ information on block I/O debugging is in Documentation/laptops/laptop-mode.txt. ============================================================== +compact_memory + +Available only when CONFIG_COMPACTION is set. When 1 is written to the file, +all zones are compacted such that free memory is available in contiguous +blocks where possible. This can be important for example in the allocation of +huge pages although processes will also directly compact memory as required. + +============================================================== + dirty_background_bytes Contains the amount of dirty memory at which the pdflush background writeback @@ -139,6 +150,20 @@ user should run `sync' first. ============================================================== +extfrag_threshold + +This parameter affects whether the kernel will compact memory or direct +reclaim to satisfy a high-order allocation. /proc/extfrag_index shows what +the fragmentation index for each order is in each zone in the system. Values +tending towards 0 imply allocations would fail due to lack of memory, +values towards 1000 imply failures are due to fragmentation and -1 implies +that the allocation will succeed as long as watermarks are met. + +The kernel will not compact memory in a zone if the +fragmentation index is <= extfrag_threshold. The default value is 500. + +============================================================== + hugepages_treat_as_movable This parameter is only useful when kernelcore= is specified at boot time to |