On Sun, Nov 23, 2014 at 09:42:12PM -0800, Jaegeuk Kim wrote: > On Thu, Nov 20, 2014 at 01:38:51PM +0900, Changman Lee wrote: > > On Fri, Nov 14, 2014 at 02:53:02PM +0900, Changman Lee wrote: > > > 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. > > > > > > > Hi, > > > > This is the result of kernel compile on xen-4.4 enabled tmem > > : cleancache and frontswap. > > I'm afraid that there is little difference by cleancache. > > The cleancache shows a few cache hits but the effect through it doesn't > > show. I don't know best benchmark to testify it yet. > > Finally, I couldn't discover any bug during test. > > > > [before patch] > > 1 2 3 > > Elapsed time 25:00.67 25:07.09 25:00.38 > > Major fault 31100 31410 31333 > > Minor fault 276869398 276869318 276871144 > > > > [after patch] > > 1 2 3 > > Elapsed time 25:12.34 25:13.29 25:11.99 > > Major fault 31559 32069 31801 > > Minor fault 276870283 276868046 276869251 > > > > [cleancache] - diff between start and end > > 1 2 3 > > failed_gets 1277980 1296355 1300368 > > invalidates 2588227 2651722 2655285 > > puts 1289970 1323685 1320623 > > *succ_gets* 111111 121299 114310 > > Hi Changman, > > So, what is your suggestion? > IMO, we first need to find a way exploiting cleancache over f2fs, so that > we can introduce some guide for users. > Until then, how about keeping this patch for a while? > The performance of cleancache depends on workload but ext4 and btrfs support it already. So how about allowing to enable cleancache on f2fs? If backend of cleancache doesn't exists, there is no effect for f2fs. I think negative effectness of cleancache is little. Anyway, a final decision lies in your hand. Thanks > Thanks, > > > > > Thanks, > > Changman > > > > > > 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 > > > > > > ------------------------------------------------------------------------------ > > > 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
