On Sat 28-09-13 08:31:19, Wu Fengguang wrote: > Hi Jan, > > On Thu, Sep 26, 2013 at 09:23:58PM +0200, Jan Kara wrote: > > When there are processes heavily creating small files while sync(2) is > > running, it can easily happen that quite some new files are created > > between WB_SYNC_NONE and WB_SYNC_ALL pass of sync(2). That can happen > > especially if there are several busy filesystems (remember that sync > > traverses filesystems sequentially and waits in WB_SYNC_ALL phase on one > > fs before starting it on another fs). Because WB_SYNC_ALL pass is slow > > (e.g. causes a transaction commit and cache flush for each inode in > > ext3), resulting sync(2) times are rather large. > > This is a very good change. An old problem that may worth noting here > is that inode_dirtied_after() has a workaround for the inodes whose > ->dirtied_when is never updated due to being constantly redirtied. > That workaround still leaves a small time window that sync() may skip > a should-be-synced inode. Since the problem existed before this patch > so I'm fine with this change. Thanks for review. Do you mean the situation when jiffies in inode->dirtied_when essentially wrap around on 32-bit systems wrt current time? Yes, that is still a problem for which I don't know a better fix than the current workaround. Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- 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
