Dan Magenheimer <dan.magenheimer@xxxxxxxxxx> writes: > [PATCH V8 1/8] mm/fs: cleancache documentation > > This patchset introduces cleancache, an optional new feature exposed > by the VFS layer that potentially dramatically increases page cache > effectiveness for many workloads in many environments at a negligible > cost. It does this by providing an interface to transcendent memory, > which is memory/storage that is not otherwise visible to and/or directly > addressable by the kernel. > > Instead of being discarded, hooks in the reclaim code "put" clean > pages to cleancache. Filesystems that "opt-in" may "get" pages > from cleancache that were previously put, but pages in cleancache are > "ephemeral", meaning they may disappear at any time. And the size > of cleancache is entirely dynamic and unknowable to the kernel. > Filesystems currently supported by this patchset include ext3, ext4, > btrfs, and ocfs2. Other filesystems (especially those built entirely > on VFS) should be easy to add, but should first be thoroughly tested to > ensure coherency. > > Details and a FAQ are provided in Documentation/vm/cleancache.txt > > This first patch of eight in this cleancache series only adds two > new documentation files. Another question: why can't this enable/disable per sb, e.g. via mount options? (I have the interest the cache stuff like this by SSD on physical systems like dragonfly's swapcache.) Well, anyway, I guess force enabling this for mostly unused sb can just add cache-write overhead and call for unpleasing reclaim to backend (because of limited space of backend) like updatedb. And already there is in FAQ though, I also have interest about async interface because of SDD backend (I'm not sure for now though). Is there any plan like SSD backend? Thanks. -- OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> -- 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
