diff options
Diffstat (limited to 'Documentation/sysctl/vm.txt')
| -rw-r--r-- | Documentation/sysctl/vm.txt | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 9832ec52f..a4482fcea 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -225,11 +225,11 @@ with your system. To disable them, echo 4 (bit 3) into drop_caches. 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. +reclaim to satisfy a high-order allocation. The extfrag/extfrag_index file in +debugfs 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. @@ -349,7 +349,7 @@ zone[i]'s protection[j] is calculated by following expression. (i < j): zone[i]->protection[j] - = (total sums of present_pages from zone[i+1] to zone[j] on the node) + = (total sums of managed_pages from zone[i+1] to zone[j] on the node) / lowmem_reserve_ratio[i]; (i = j): (should not be protected. = 0; @@ -360,7 +360,7 @@ The default values of lowmem_reserve_ratio[i] are 256 (if zone[i] means DMA or DMA32 zone) 32 (others). As above expression, they are reciprocal number of ratio. -256 means 1/256. # of protection pages becomes about "0.39%" of total present +256 means 1/256. # of protection pages becomes about "0.39%" of total managed pages of higher zones on the node. If you would like to protect more pages, smaller values are effective. |