On 05.06.2015 17:56, Alberto Garcia wrote:
On Fri 05 Jun 2015 05:52:29 PM CEST, Max Reitz wrote:
+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)
+after which all unused cache entries are removed from memory.
+
+This 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 0 and it disables
+this feature.
+
+Note that this functionality currently relies on the MADV_DONTNEED
+argument for madvise() to actually free the memory, so it is not
+useful in systems that don't follow that behavior.
I'd like a definition of what "unused" means (I know because of this
series, but I wouldn't know just from this document).
It means that it hasn't been accessed in that interval (because it was
not needed). Are you thinking of any other possible interpretation?
Well... To me, intuitively, "unused" entries in a cache are just empty
entries. Just replacing one occurrence of "unused" by "not accessed
during the past interval" or something like that would resolve the
riddle for me. :-)
Max
