On 07/05/2011 09:38 PM, Wengang Wang wrote: > There is a use case that the app deletes huge number(XX kilo) of files in > every > 5 minutes. The deletions of some specific files are extreamly slow(costing > xx~xxx seconds). That is unacceptable. > > Reading out the dir entries and the relavent inodes cost time. And we are > doing > that with i_mutex held, it causes unlink path waiting on the mutex for long > time. > > fix: > We drops and retake the mutex in the duration giving change to unlink to go > on. > Also, for live nodes, one node only scan and recover this slot where the node > resides(helps performance). And always do it at each scan time. For those dead > (not mounted), we do it when we "should". And for dead slots, no > dropping-retaking > mutex is needed.
Yes, this is a good issue to tackle. I will read the patch in greater detail later. But offhand, I have two comments. 1. "should" is not descriptive. I am assuming you mean do it only during actual recovery. If so, that would be incorrect. Say node 0 unlinks a file that was being used by node 1. Node 0 dies. Recovery will notice that that inode is active and not delete it. If node 1 dies, or is unable to delete the file for any other reason, then our only hope is orphan scan. 2. All nodes have to scan all slots. Even live slots. I remember we did for a reason. And that reason should be in the comment in the patch written by Srini. _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com http://oss.oracle.com/mailman/listinfo/ocfs2-devel
