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?