On Wed, Jul 23, 2008 at 10:40:47PM +0530, Aneesh Kumar K.V wrote:
> Currently locality group prealloc list is freed only when there is a block allocation
> failure. This can result in large number of per cpu locality group prealloc space
> and also make the ext4_mb_use_preallocated expensive. Convert the locality group
> prealloc list to a hash list. The hash index is the order of number of blocks
> in the prealloc space with a max order of 9. When adding prealloc space to the
> list we make sure total entries for each order does not exceed 8. If it is more
> than 8 we discard few entries and make sure the we have only <= 5 entries.
So the second sentence made my english parser core dump. :-)
I rewrote the patch comments as follows; is it still a fair summary?
Currently, the locality group prealloc list is freed only when there
is a block allocation failure. This can result in large number of
entries in the preallocation list making ext4_mb_use_preallocated()
expensive.
To fix this, we convert the locality group prealloc list to a hash
list. The hash index is the order of number of blocks in the prealloc
space with a max order of 9. When adding prealloc space to the list we
make sure total entries for each order does not exceed 8. If it is
more than 8 we discard few entries and make sure the we have only <= 5
entries.
- Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
