On Feb 20, 2015, at 1:50 AM, Michael Kerrisk <mtk.manpages@xxxxxxxxx> wrote: > > Hello Ted, > > Based on your commit message 0ae45f63d4e, I I wrote the documentation > below for MS_LAZYTIME, to go into the mount(2) man page. Could you > please check it over and let me know if it's accurate. In particular, > I added pieces marked with "*" below that were not part of the commit > message and I'd like confirmation that they're accurate. > > Thanks, > > Michael > > [[ > MS_LAZYTIME (since Linux 3.20) > Only update filetimes (atime, mtime, ctime) on the in- > memory version of the file inode. The on-disk time‐ > stamps are updated only when: > > (a) the inode needs to be updated for some change unre‐ > lated to file timestamps; > > (b) the application employs fsync(2), syncfs(2), or > sync(2); > > (c) an undeleted inode is evicted from memory; or > > * (d) more than 24 hours have passed since the i-node was > * written to disk. > > This mount option significantly reduces writes to the > inode table for workloads that perform frequent random > writes to preallocated files. > > * As at Linux 3.20, this option is supported only on ext4. I _think_ that the lazytime mount option is generic for all filesystems. I believe ext4 has an extra optimization for it, but that's it. Cheers, Andreas -- 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
