diff options
Diffstat (limited to 'Documentation/vm/ksm.txt')
-rw-r--r-- | Documentation/vm/ksm.txt | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/vm/ksm.txt b/Documentation/vm/ksm.txt index 72a22f65960e..262d8e6793a3 100644 --- a/Documentation/vm/ksm.txt +++ b/Documentation/vm/ksm.txt | |||
@@ -52,15 +52,15 @@ The KSM daemon is controlled by sysfs files in /sys/kernel/mm/ksm/, | |||
52 | readable by all but writable only by root: | 52 | readable by all but writable only by root: |
53 | 53 | ||
54 | max_kernel_pages - set to maximum number of kernel pages that KSM may use | 54 | max_kernel_pages - set to maximum number of kernel pages that KSM may use |
55 | e.g. "echo 2000 > /sys/kernel/mm/ksm/max_kernel_pages" | 55 | e.g. "echo 100000 > /sys/kernel/mm/ksm/max_kernel_pages" |
56 | Value 0 imposes no limit on the kernel pages KSM may use; | 56 | Value 0 imposes no limit on the kernel pages KSM may use; |
57 | but note that any process using MADV_MERGEABLE can cause | 57 | but note that any process using MADV_MERGEABLE can cause |
58 | KSM to allocate these pages, unswappable until it exits. | 58 | KSM to allocate these pages, unswappable until it exits. |
59 | Default: 2000 (chosen for demonstration purposes) | 59 | Default: quarter of memory (chosen to not pin too much) |
60 | 60 | ||
61 | pages_to_scan - how many present pages to scan before ksmd goes to sleep | 61 | pages_to_scan - how many present pages to scan before ksmd goes to sleep |
62 | e.g. "echo 200 > /sys/kernel/mm/ksm/pages_to_scan" | 62 | e.g. "echo 100 > /sys/kernel/mm/ksm/pages_to_scan" |
63 | Default: 200 (chosen for demonstration purposes) | 63 | Default: 100 (chosen for demonstration purposes) |
64 | 64 | ||
65 | sleep_millisecs - how many milliseconds ksmd should sleep before next scan | 65 | sleep_millisecs - how many milliseconds ksmd should sleep before next scan |
66 | e.g. "echo 20 > /sys/kernel/mm/ksm/sleep_millisecs" | 66 | e.g. "echo 20 > /sys/kernel/mm/ksm/sleep_millisecs" |
@@ -70,7 +70,8 @@ run - set 0 to stop ksmd from running but keep merged pages, | |||
70 | set 1 to run ksmd e.g. "echo 1 > /sys/kernel/mm/ksm/run", | 70 | set 1 to run ksmd e.g. "echo 1 > /sys/kernel/mm/ksm/run", |
71 | set 2 to stop ksmd and unmerge all pages currently merged, | 71 | set 2 to stop ksmd and unmerge all pages currently merged, |
72 | but leave mergeable areas registered for next run | 72 | but leave mergeable areas registered for next run |
73 | Default: 1 (for immediate use by apps which register) | 73 | Default: 0 (must be changed to 1 to activate KSM, |
74 | except if CONFIG_SYSFS is disabled) | ||
74 | 75 | ||
75 | The effectiveness of KSM and MADV_MERGEABLE is shown in /sys/kernel/mm/ksm/: | 76 | The effectiveness of KSM and MADV_MERGEABLE is shown in /sys/kernel/mm/ksm/: |
76 | 77 | ||
@@ -86,4 +87,4 @@ pages_volatile embraces several different kinds of activity, but a high | |||
86 | proportion there would also indicate poor use of madvise MADV_MERGEABLE. | 87 | proportion there would also indicate poor use of madvise MADV_MERGEABLE. |
87 | 88 | ||
88 | Izik Eidus, | 89 | Izik Eidus, |
89 | Hugh Dickins, 30 July 2009 | 90 | Hugh Dickins, 24 Sept 2009 |