| Message ID | 20220901220138.182896-1-vishal.moola@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Convert to filemap_get_folios_tag() | expand |
On Thu, Sep 01, 2022 at 03:01:15PM -0700, Vishal Moola (Oracle) wrote: > This patch series replaces find_get_pages_range_tag() with > filemap_get_folios_tag(). This also allows the removal of multiple > calls to compound_head() throughout. > It also makes a good chunk of the straightforward conversions to folios, > and takes the opportunity to introduce a function that grabs a folio > from the pagecache. > > F2fs and Ceph have quite alot of work to be done regarding folios, so > for now those patches only have the changes necessary for the removal of > find_get_pages_range_tag(), and only support folios of size 1 (which is > all they use right now anyways). > > I've run xfstests on btrfs, ext4, f2fs, and nilfs2, but more testing may be > beneficial. Well, that answers my question about how filesystems that enable multi-page folios were tested: they weren't. I'd suggest that anyone working on further extending the filemap/folio infrastructure really needs to be testing XFS as a first priority, and then other filesystems as a secondary concern. That's because XFS (via the fs/iomap infrastructure) is one of only 3 filesystems in the kernel (AFS and tmpfs are the others) that interact with the page cache and page cache "pages" solely via folio interfaces. As such they are able to support multi-page folios in the page cache. All of the tested filesystems still use the fixed PAGE_SIZE page interfaces to interact with the page cache, so they don't actually exercise interactions with multi-page folios at all. Hence if you are converting generic infrastructure that looks up pages in the page cache to look up folios in the page cache, the code that processes the returned folios also needs to be updated and validated to ensure that it correctly handles multi-page folios. And the only way you can do that fully at this point in time is via testing XFS or AFS... Cheers, Dave.
On Wed, Oct 19, 2022 at 08:45:44AM +1100, Dave Chinner wrote: > On Thu, Sep 01, 2022 at 03:01:15PM -0700, Vishal Moola (Oracle) wrote: > > This patch series replaces find_get_pages_range_tag() with > > filemap_get_folios_tag(). This also allows the removal of multiple > > calls to compound_head() throughout. > > It also makes a good chunk of the straightforward conversions to folios, > > and takes the opportunity to introduce a function that grabs a folio > > from the pagecache. > > > > F2fs and Ceph have quite alot of work to be done regarding folios, so > > for now those patches only have the changes necessary for the removal of > > find_get_pages_range_tag(), and only support folios of size 1 (which is > > all they use right now anyways). > > > > I've run xfstests on btrfs, ext4, f2fs, and nilfs2, but more testing may be > > beneficial. > > Well, that answers my question about how filesystems that enable > multi-page folios were tested: they weren't. > > I'd suggest that anyone working on further extending the > filemap/folio infrastructure really needs to be testing XFS as a > first priority, and then other filesystems as a secondary concern. > > That's because XFS (via the fs/iomap infrastructure) is one of only > 3 filesystems in the kernel (AFS and tmpfs are the others) that > interact with the page cache and page cache "pages" solely via folio > interfaces. As such they are able to support multi-page folios in > the page cache. All of the tested filesystems still use the fixed > PAGE_SIZE page interfaces to interact with the page cache, so they > don't actually exercise interactions with multi-page folios at all. > Thanks for the explanation! That makes perfect sense. I wholeheartedly agree, and I'll be sure to test any future changes on XFS to try to ensure multi-page folio functionality. I know David ran tests on AFS, so hopefully those hit multipage folios well enough. But I'm not sure whether it was just for the AFS patch or with the whole series applied. Regardless I'll run my own set of tests on XFS and see if I run into any issues as well.
This patch series replaces find_get_pages_range_tag() with filemap_get_folios_tag(). This also allows the removal of multiple calls to compound_head() throughout. It also makes a good chunk of the straightforward conversions to folios, and takes the opportunity to introduce a function that grabs a folio from the pagecache. F2fs and Ceph have quite alot of work to be done regarding folios, so for now those patches only have the changes necessary for the removal of find_get_pages_range_tag(), and only support folios of size 1 (which is all they use right now anyways). I've run xfstests on btrfs, ext4, f2fs, and nilfs2, but more testing may be beneficial. The page-writeback and filemap changes implicitly work. Testing and review of the other changes (afs, ceph, cifs, gfs2) would be appreciated. Vishal Moola (Oracle) (23): pagemap: Add filemap_grab_folio() filemap: Added filemap_get_folios_tag() filemap: Convert __filemap_fdatawait_range() to use filemap_get_folios_tag() page-writeback: Convert write_cache_pages() to use filemap_get_folios_tag() afs: Convert afs_writepages_region() to use filemap_get_folios_tag() btrfs: Convert btree_write_cache_pages() to use filemap_get_folio_tag() btrfs: Convert extent_write_cache_pages() to use filemap_get_folios_tag() ceph: Convert ceph_writepages_start() to use filemap_get_folios_tag() cifs: Convert wdata_alloc_and_fillpages() to use filemap_get_folios_tag() ext4: Convert mpage_prepare_extent_to_map() to use filemap_get_folios_tag() f2fs: Convert f2fs_fsync_node_pages() to use filemap_get_folios_tag() f2fs: Convert f2fs_flush_inline_data() to use filemap_get_folios_tag() f2fs: Convert f2fs_sync_node_pages() to use filemap_get_folios_tag() f2fs: Convert f2fs_write_cache_pages() to use filemap_get_folios_tag() f2fs: Convert last_fsync_dnode() to use filemap_get_folios_tag() f2fs: Convert f2fs_sync_meta_pages() to use filemap_get_folios_tag() gfs2: Convert gfs2_write_cache_jdata() to use filemap_get_folios_tag() nilfs2: Convert nilfs_lookup_dirty_data_buffers() to use filemap_get_folios_tag() nilfs2: Convert nilfs_lookup_dirty_node_buffers() to use filemap_get_folios_tag() nilfs2: Convert nilfs_btree_lookup_dirty_buffers() to use filemap_get_folios_tag() nilfs2: Convert nilfs_copy_dirty_pages() to use filemap_get_folios_tag() nilfs2: Convert nilfs_clear_dirty_pages() to use filemap_get_folios_tag() filemap: Remove find_get_pages_range_tag() fs/afs/write.c | 114 +++++++++++++++++---------------- fs/btrfs/extent_io.c | 57 +++++++++-------- fs/ceph/addr.c | 138 ++++++++++++++++++++-------------------- fs/cifs/file.c | 33 +++++++++- fs/ext4/inode.c | 55 ++++++++-------- fs/f2fs/checkpoint.c | 49 +++++++------- fs/f2fs/compress.c | 13 ++-- fs/f2fs/data.c | 67 ++++++++++--------- fs/f2fs/f2fs.h | 5 +- fs/f2fs/node.c | 72 +++++++++++---------- fs/gfs2/aops.c | 64 ++++++++++--------- fs/nilfs2/btree.c | 14 ++-- fs/nilfs2/page.c | 59 ++++++++--------- fs/nilfs2/segment.c | 44 +++++++------ include/linux/pagemap.h | 32 +++++++--- include/linux/pagevec.h | 8 --- mm/filemap.c | 87 ++++++++++++------------- mm/page-writeback.c | 44 +++++++------ mm/swap.c | 10 --- 19 files changed, 506 insertions(+), 459 deletions(-)