On 11-07-05 23:17, Sunil Mushran wrote: > 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.
Sorry. the "should" doesn't mean a actual recovery. I meant when "os->os_seqno == seqno", the orginal condition determining whether we do queue the scans. > > 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. Oh... I will check Srini's patch. thanks, wengang. _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com http://oss.oracle.com/mailman/listinfo/ocfs2-devel
