On Sat, 12 Sep 2009, Mike Snitzer wrote: > On Fri, Sep 11 2009 at 2:51am -0400, > Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > > > Mikulas, > > > > I ran with your suggestion and it works quite well (results below). > ... > > The changes are detailed at the end of this mail. I still have a "TODO" > > that you'll see in the patch that speaks to needing to have > > snapshot_merge_process() check all origin chunks via __chunk_is_tracked() > > rather than just the one check of the first chunk. Your feedback here > > would be much appreciated. I'm not completely clear on the intent of > > the __chunk_is_tracked() check there and what it now needs to do. > > I believe I've sorted this out. The TODO should've read something like: > snapshot_merge_process() should delay the merging of _all_ chunks > that have in-progress writes; not just the first chunk in the region > that is to be merged. > > The revised patch (relative to Jon's unified snapshot tree) is here: > http://people.redhat.com/msnitzer/patches/snapshot-merge/kernel_unified/2.6.31/dm-snapshot-merge-use-larger-io-when-merging.patch > > Pretty sure it _should_ work; but can't test until we get this unified > snapshot patchset working properly. Yes, that's right. The purpose of the tracking while merging is to exclude pending writes to the region that is being merged --- so we must wait for writes on all chunks. The patch seems fine. Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
