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Diffstat (limited to 'Documentation/sysctl/vm.txt')
| -rw-r--r-- | Documentation/sysctl/vm.txt | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 9baf66a9ef4e..1d1f2cb5abc8 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -30,6 +30,7 @@ Currently, these files are in /proc/sys/vm: - dirty_writeback_centisecs - drop_caches - extfrag_threshold +- extra_free_kbytes - hugepages_treat_as_movable - hugetlb_shm_group - laptop_mode @@ -260,6 +261,21 @@ any throttling. ============================================================== +extra_free_kbytes + +This parameter tells the VM to keep extra free memory between the threshold +where background reclaim (kswapd) kicks in, and the threshold where direct +reclaim (by allocating processes) kicks in. + +This is useful for workloads that require low latency memory allocations +and have a bounded burstiness in memory allocations, for example a +realtime application that receives and transmits network traffic +(causing in-kernel memory allocations) with a maximum total message burst +size of 200MB may need 200MB of extra free memory to avoid direct reclaim +related latencies. + +============================================================== + hugepages_treat_as_movable This parameter controls whether we can allocate hugepages from ZONE_MOVABLE |