On Thu, Apr 02, 2020 at 10:54:07AM +1100, NeilBrown wrote: > > After an NFS page has been written it is considered "unstable" until a > COMMIT request succeeds. If the COMMIT fails, the page will be > re-written. > > These "unstable" pages are currently accounted as "reclaimable", > either in WB_RECLAIMABLE, or in NR_UNSTABLE_NFS which is included in a > 'reclaimable' count. This might have made sense when sending the COMMIT > required a separate action by the VFS/MM (e.g. releasepage() used to > send a COMMIT). However now that all writes generated by ->writepages() > will automatically be followed by a COMMIT, it makes more sense to > treat them as writeback pages. > > So this page deprecates NR_UNSTABLE_NFS and accounts unstable pages in > NR_WRITEBACK and WB_WRITEBACK. Please remove it entirely if it isn't used any more.
