On Thu, Jun 02, 2016 at 02:44:30PM +0200, Holger Hoffstätte wrote: > On 06/02/16 14:13, Stefan Priebe - Profihost AG wrote: > > > > Am 31.05.2016 um 09:31 schrieb Dave Chinner: > >> On Tue, May 31, 2016 at 08:11:42AM +0200, Stefan Priebe - Profihost AG wrote: > >>>> I'm half tempted at this point to mostly ignore this mm/ behavour > >>>> because we are moving down the path of removing buffer heads from > >>>> XFS. That will require us to do different things in ->releasepage > >>>> and so just skipping dirty pages in the XFS code is the best thing > >>>> to do.... > >>> > >>> does this change anything i should test? Or is 4.6 still the way to go? > >> > >> Doesn't matter now - the warning will still be there on 4.6. I think > >> you can simply ignore it as the XFS code appears to be handling the > >> dirty page that is being passed to it correctly. We'll work out what > >> needs to be done to get rid of the warning for this case, wether it > >> be a mm/ change or an XFS change. > > > > Any idea what i could do with 4.4.X? Can i safely remove the WARN_ONCE > > statement? > > By definition it won't break anything since it's just a heads-up message, > so yes, it should be "safe". However if my understanding of the situation > is correct, mainline commit f0281a00fe "mm: workingset: only do workingset > activations on reads" (+ friends) in 4.7 should effectively prevent this > from happenning. Can someone confirm or deny this? I don't think it will. The above commits will avoid putting /write-only/ dirty pages on the active list from the write() syscall vector, but it won't prevent pages that are read first then dirtied from ending up on the active list. e.g. a mmap write will first read the page from disk to populate the page (hence it ends up on the active list), then the page gets dirtied and ->page_mkwrite is called to tell the filesystem.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
