Searched hist:"2693310 e" (Results 1 – 1 of 1) sorted by relevance
/qemu/block/ |
H A D | qcow2-cache.c | 2693310e Mon May 11 12:54:55 GMT 2015 Alberto Garcia <berto@igalia.com> qcow2: use an LRU algorithm to replace entries from the L2 cache
The current algorithm to evict entries from the cache gives always preference to those in the lowest positions. As the size of the cache increases, the chances of the later elements of being removed decrease exponentially.
In a scenario with random I/O and lots of cache misses, entries in positions 8 and higher are rarely (if ever) evicted. This can be seen even with the default cache size, but with larger caches the problem becomes more obvious.
Using an LRU algorithm makes the chances of being removed from the cache independent from the position.
Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
|