On Thu, Nov 13, 2014 at 05:27:51PM -0800, Jaegeuk Kim wrote: > Hi Changman, > > On Thu, Nov 13, 2014 at 02:34:50PM +0900, Changman Lee wrote: > > To use cleancache, fs must explicitly enable cleancache by calling > > cleancache_init_fs. > > Good catch! > > Prior to merge this patch, can you share any testing results or performance > numbers? > Not yet, I'll try to get numbers. > What condition will be the best way to exploit f2fs and cleancache? > Not clear. I think we can make a cleancache client for f2fs so that can compenstate a penalty of node pages which are read mostly. > Can we confirm that f2fs satisfies most of requirements described by > cleancache.txt below? Good point. At a quick glance, F2FS seems to satisfy most of requirements. Through a experimental, I'll try to check side effect. > > Some points for a filesystem to consider: > > - The FS should be block-device-based (e.g. a ram-based FS such > as tmpfs should not enable cleancache) > - To ensure coherency/correctness, the FS must ensure that all > file removal or truncation operations either go through VFS or > add hooks to do the equivalent cleancache "invalidate" operations > - To ensure coherency/correctness, either inode numbers must > be unique across the lifetime of the on-disk file OR the > FS must provide an "encode_fh" function. > - The FS must call the VFS superblock alloc and deactivate routines > or add hooks to do the equivalent cleancache calls done there. > - To maximize performance, all pages fetched from the FS should > go through the do_mpag_readpage routine or the FS should add > hooks to do the equivalent (cf. btrfs) > - Currently, the FS blocksize must be the same as PAGESIZE. This > is not an architectural restriction, but no backends currently > support anything different. > - A clustered FS should invoke the "shared_init_fs" cleancache > hook to get best performance for some backends. > > Thanks, > > > > > Signed-off-by: Changman Lee <cm224.lee@xxxxxxxxxxx> > > --- > > fs/f2fs/super.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > > index 512ffd8..2ebb960 100644 > > --- a/fs/f2fs/super.c > > +++ b/fs/f2fs/super.c > > @@ -24,6 +24,7 @@ > > #include <linux/blkdev.h> > > #include <linux/f2fs_fs.h> > > #include <linux/sysfs.h> > > +#include <linux/cleancache.h> > > > > #include "f2fs.h" > > #include "node.h" > > @@ -1144,6 +1145,8 @@ try_onemore: > > if (err) > > goto free_kobj; > > } > > + > > + cleancache_init_fs(sb); > > return 0; > > > > free_kobj: > > -- > > 1.9.1 > > > > > > ------------------------------------------------------------------------------ > > Comprehensive Server Monitoring with Site24x7. > > Monitor 10 servers for $9/Month. > > Get alerted through email, SMS, voice calls or mobile push notifications. > > Take corrective actions from your mobile device. > > http://pubads.g.doubleclick.net/gampad/clk?id=154624111&iu=/4140/ostg.clktrk > > _______________________________________________ > > Linux-f2fs-devel mailing list > > Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
