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Diffstat (limited to 'Documentation/sysctl')
| -rw-r--r-- | Documentation/sysctl/vm.txt | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 89a887c76629..cb0368459da3 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -803,6 +803,24 @@ performance impact. Reclaim code needs to take various locks to find freeable directory and inode objects. With vfs_cache_pressure=1000, it will look for ten times more freeable objects than there are. +============================================================= + +watermark_scale_factor: + +This factor controls the aggressiveness of kswapd. It defines the +amount of memory left in a node/system before kswapd is woken up and +how much memory needs to be free before kswapd goes back to sleep. + +The unit is in fractions of 10,000. The default value of 10 means the +distances between watermarks are 0.1% of the available memory in the +node/system. The maximum value is 1000, or 10% of memory. + +A high rate of threads entering direct reclaim (allocstall) or kswapd +going to sleep prematurely (kswapd_low_wmark_hit_quickly) can indicate +that the number of free pages kswapd maintains for latency reasons is +too small for the allocation bursts occurring in the system. This knob +can then be used to tune kswapd aggressiveness accordingly. + ============================================================== zone_reclaim_mode: |