On Tue, Feb 09, 2021 at 04:11:23PM +0100, David Sterba wrote: > On Fri, Feb 05, 2021 at 03:23:00PM -0800, ira.weiny@xxxxxxxxx wrote: > > From: Ira Weiny <ira.weiny@xxxxxxxxx> > > > > There are many places where kmap/<operation>/kunmap patterns occur. We lift > > these various patterns to core common functions and use them in the btrfs file > > system. At the same time we convert those core functions to use > > kmap_local_page() which is more efficient in those calls. > > > > I think this is best accepted through Andrew's tree as it has the mem*_page > > functions in it. But I'd like to get an ack from David or one of the other > > btrfs maintainers before the btrfs patches go through. > > I'd rather take the non-mm patches through my tree so it gets tested > the same way as other btrfs changes, straightforward cleanups or not. True. > > This brings the question how to do that as the first patch should go > through the MM tree. One option is to posptpone the actual cleanups > after the 1st patch is merged but this could take a long delay. > > I'd suggest to take the 1st patch within MM tree in the upcoming merge > window and then I can prepare a separate pull with just the cleanups. > Removing an inter-tree patch dependency was a sufficient reason for > Linus in the past for such pull requests. There are others how want this base patch too.[1] So I like this option. > > > There are a lot more kmap->kmap_local_page() conversions but kmap_local_page() > > requires some care with the unmapping order and so I'm still reviewing those > > changes because btrfs uses a lot of loops for it's kmaps. > > It sounds to me that converting the kmaps will take some time anyway so > exporting the helpers first and then converting the subsystems might be > a good option. In case you'd like to get rid of the simple cases in > btrfs code now we can do the 2 pull requests. I would really like to get the simple case out of the way because the next series has more difficult changes and the simple cases always cause me trouble when grepping/coccinelle'ing for things. So I would like a follow on pull request if possible. But I'm willing to do what works best for you. For now I will spin a new version with the changes you've requested ASAP. Ira [1] https://lore.kernel.org/linux-f2fs-devel/20210207190425.38107-1-chaitanya.kulkarni@xxxxxxx/
