On Thu, Apr 21, 2011 at 2:44 PM, Colin McCabe <[email protected]> wrote: > On Thu, Apr 21, 2011 at 2:23 PM, Yehuda Sadeh Weinraub > <[email protected]> wrote: >> On Thu, Apr 21, 2011 at 2:09 PM, Colin McCabe <[email protected]> wrote: >>> On Thu, Apr 21, 2011 at 1:03 PM, Gregory Farnum >>> <[email protected]> wrote: >>>> I really don't see how pushing the naming complexity into the local >>>> filesystem, >>>> where it adds lots of otherwise-useless inodes and dentries, is going to >>>> help us. >>> >>> Here is a quick summary of how the TV's proposal would help us. >>> 1. it avoids collisions entirely >>> 2. You don't ever have do an extra xattr lookup, no matter how short >>> or long the object name is. >> >> Yeah, but you read more directories. Note that btrfs stores the xattrs >> on the directories, so reading those xattrs will have a lower IO >> impact than traversing directories recursively. > > It does seem like btrfs' extended attribute implementation is fairly > efficient. But Linux's dentry cache (dcache) is also pretty efficient. > (resending to list)
It needs to be populated first before being efficient. And it'll be less efficient now that you populate it with extra entries. Yehuda -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
