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| author | Leonid Bloch <lbloch@janustech.com> | 2018-09-29 12:54:54 +0300 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2018-10-01 19:13:55 +0200 |
| commit | e3a7b4556ee33feba2b396769a9c8354be06b024 (patch) | |
| tree | 77f4fb856064b60dbc26460ef96cfe37cf594f67 /docs/qcow2-cache.txt | |
| parent | cb53460b708db3617ab73248374d071d5552c263 (diff) | |
qcow2: Fix cache-clean-interval documentation
Fixing cache-clean-interval documentation following the recent change to
a default of 600 seconds on supported plarforms (only Linux currently).
Signed-off-by: Leonid Bloch <lbloch@janustech.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'docs/qcow2-cache.txt')
| -rw-r--r-- | docs/qcow2-cache.txt | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt index 59358b816f..c459bf5dd3 100644 --- a/docs/qcow2-cache.txt +++ b/docs/qcow2-cache.txt @@ -202,18 +202,18 @@ Reducing the memory usage It is possible to clean unused cache entries in order to reduce the memory usage during periods of low I/O activity. -The parameter "cache-clean-interval" defines an interval (in seconds). -All cache entries that haven't been accessed during that interval are -removed from memory. +The parameter "cache-clean-interval" defines an interval (in seconds), +after which all the cache entries that haven't been accessed during the +interval are removed from memory. Setting this parameter to 0 disables this +feature. -This example removes all unused cache entries every 15 minutes: +The following example removes all unused cache entries every 15 minutes: -drive file=hd.qcow2,cache-clean-interval=900 -If unset, the default value for this parameter is 600. Setting it to 0 -disables this feature. +If unset, the default value for this parameter is 600 on platforms which +support this functionality, and is 0 (disabled) on other platforms. -Note that this functionality currently relies on the MADV_DONTNEED -argument for madvise() to actually free the memory. This is a -Linux-specific feature, so cache-clean-interval is not supported in -other systems. +This functionality currently relies on the MADV_DONTNEED argument for +madvise() to actually free the memory. This is a Linux-specific feature, +so cache-clean-interval is not supported on other systems. |