[PATCH v13 000/137] Memory folios

Matthew Wilcox (Oracle)
2021-07-12T03:08:53Z

Managing memory in 4KiB pages is a serious overhead. Many benchmarks
benefit from a larger "page size". As an example, an earlier iteration
of this idea which used compound pages (and wasn't particularly tuned)
got a 7% performance boost when compiling the kernel.

Using compound pages or THPs exposes a weakness of our type system.
Functions are often unprepared for compound pages to be passed to them,
and may only act on PAGE_SIZE chunks. Even functions which are aware of
compound pages may expect a head page, and do the wrong thing if passed
a tail page.

We also waste a lot of instructions ensuring that we're not looking at
a tail page. Almost every call to PageFoo() contains one or more hidden
calls to compound_head(). This also happens for get_page(), put_page()
and many more functions.

This patch series uses a new type, the struct folio, to manage memory.
It converts enough of the page cache, iomap and XFS to use folios instead
of pages, and then adds support for multi-page folios. It passes xfstests
(running on XFS) with no regressions compared to v5.14-rc1.

Git: https://git.infradead.org/users/willy/pagecache.git/shortlog/refs/tags/folio_13

Matthew Wilcox (Oracle) (137):
mm: Convert get_page_unless_zero() to return bool
mm: Introduce struct folio
mm: Add folio_pgdat(), folio_zone() and folio_zonenum()
mm/vmstat: Add functions to account folio statistics
mm/debug: Add VM_BUG_ON_FOLIO() and VM_WARN_ON_ONCE_FOLIO()
mm: Add folio reference count functions
mm: Add folio_put()
mm: Add folio_get()
mm: Add folio_try_get_rcu()
mm: Add folio flag manipulation functions
mm/lru: Add folio LRU functions
mm: Handle per-folio private data
mm/filemap: Add folio_index(), folio_file_page() and folio_contains()
mm/filemap: Add folio_next_index()
mm/filemap: Add folio_pos() and folio_file_pos()
mm/util: Add folio_mapping() and folio_file_mapping()
mm/filemap: Add folio_unlock()
mm/filemap: Add folio_lock()
mm/filemap: Add folio_lock_killable()
mm/filemap: Add __folio_lock_async()
mm/filemap: Add folio_wait_locked()
mm/filemap: Add __folio_lock_or_retry()
mm/swap: Add folio_rotate_reclaimable()
mm/filemap: Add folio_end_writeback()
mm/writeback: Add folio_wait_writeback()
mm/writeback: Add folio_wait_stable()
mm/filemap: Add folio_wait_bit()
mm/filemap: Add folio_wake_bit()
mm/filemap: Convert page wait queues to be folios
mm/filemap: Add folio private_2 functions
fs/netfs: Add folio fscache functions
mm: Add folio_mapped()
mm: Add folio_nid()
mm/memcg: Remove 'page' parameter to mem_cgroup_charge_statistics()
mm/memcg: Use the node id in mem_cgroup_update_tree()
mm/memcg: Remove soft_limit_tree_node()
mm/memcg: Convert memcg_check_events to take a node ID
mm/memcg: Add folio_memcg() and related functions
mm/memcg: Convert commit_charge() to take a folio
mm/memcg: Convert mem_cgroup_charge() to take a folio
mm/memcg: Convert uncharge_page() to uncharge_folio()
mm/memcg: Convert mem_cgroup_uncharge() to take a folio
mm/memcg: Convert mem_cgroup_migrate() to take folios
mm/memcg: Convert mem_cgroup_track_foreign_dirty_slowpath() to folio
mm/memcg: Add folio_memcg_lock() and folio_memcg_unlock()
mm/memcg: Convert mem_cgroup_move_account() to use a folio
mm/memcg: Add folio_lruvec()
mm/memcg: Add folio_lruvec_lock() and similar functions
mm/memcg: Add folio_lruvec_relock_irq() and
folio_lruvec_relock_irqsave()
mm/workingset: Convert workingset_activation to take a folio
mm: Add folio_pfn()
mm: Add folio_raw_mapping()
mm: Add flush_dcache_folio()
mm: Add kmap_local_folio()
mm: Add arch_make_folio_accessible()
mm: Add folio_young() and folio_idle()
mm/swap: Add folio_activate()
mm/swap: Add folio_mark_accessed()
mm/rmap: Add folio_mkclean()
mm/migrate: Add folio_migrate_mapping()
mm/migrate: Add folio_migrate_flags()
mm/migrate: Add folio_migrate_copy()
mm/writeback: Rename __add_wb_stat() to wb_stat_mod()
flex_proportions: Allow N events instead of 1
mm/writeback: Change __wb_writeout_inc() to __wb_writeout_add()
mm/writeback: Add __folio_end_writeback()
mm/writeback: Add folio_start_writeback()
mm/writeback: Add folio_mark_dirty()
mm/writeback: Add __folio_mark_dirty()
mm/writeback: Add filemap_dirty_folio()
mm/writeback: Add folio_account_cleaned()
mm/writeback: Add folio_cancel_dirty()
mm/writeback: Add folio_clear_dirty_for_io()
mm/writeback: Add folio_account_redirty()
mm/writeback: Add folio_redirty_for_writepage()
mm/filemap: Add i_blocks_per_folio()
mm/filemap: Add folio_mkwrite_check_truncate()
mm/filemap: Add readahead_folio()
mm/workingset: Convert workingset_refault() to take a folio
mm: Add folio_evictable()
mm/lru: Convert __pagevec_lru_add_fn to take a folio
mm/lru: Add folio_add_lru()
mm/page_alloc: Add folio allocation functions
mm/filemap: Add filemap_alloc_folio
mm/filemap: Add filemap_add_folio()
mm/filemap: Convert mapping_get_entry to return a folio
mm/filemap: Add filemap_get_folio
mm/filemap: Add FGP_STABLE
block: Add bio_add_folio()
block: Add bio_for_each_folio_all()
iomap: Convert to_iomap_page to take a folio
iomap: Convert iomap_page_create to take a folio
iomap: Convert iomap_page_release to take a folio
iomap: Convert iomap_releasepage to use a folio
iomap: Convert iomap_invalidatepage to use a folio
iomap: Pass the iomap_page into iomap_set_range_uptodate
iomap: Use folio offsets instead of page offsets
iomap: Convert bio completions to use folios
iomap: Convert readahead and readpage to use a folio
iomap: Convert iomap_page_mkwrite to use a folio
iomap: Convert iomap_write_begin and iomap_write_end to folios
iomap: Convert iomap_read_inline_data to take a folio
iomap: Convert iomap_write_end_inline to take a folio
iomap: Convert iomap_add_to_ioend to take a folio
iomap: Convert iomap_do_writepage to use a folio
iomap: Convert iomap_migrate_page to use folios
mm/filemap: Convert page_cache_delete to take a folio
mm/filemap: Convert unaccount_page_cache_page to
filemap_unaccount_folio
mm/filemap: Add filemap_remove_folio and __filemap_remove_folio
mm/filemap: Convert find_get_entry to return a folio
mm/filemap: Convert filemap_get_read_batch to use folios
mm/filemap: Convert find_get_pages_contig to folios
mm/filemap: Convert filemap_read_page to take a folio
mm/filemap: Convert filemap_create_page to folio
mm/filemap: Convert filemap_range_uptodate to folios
mm/filemap: Convert filemap_fault to folio
mm/filemap: Add read_cache_folio and read_mapping_folio
mm/filemap: Convert filemap_get_pages to use folios
mm/filemap: Convert page_cache_delete_batch to folios
mm/filemap: Remove PageHWPoison check from next_uptodate_page()
mm/filemap: Use folios in next_uptodate_page
mm/filemap: Use a folio in filemap_map_pages
fs: Convert vfs_dedupe_file_range_compare to folios
mm/truncate,shmem: Handle truncates that split THPs
mm/filemap: Return only head pages from find_get_entries
mm: Use multi-index entries in the page cache
iomap: Support multi-page folios in invalidatepage
xfs: Support THPs
mm/truncate: Convert invalidate_inode_pages2_range to folios
mm/truncate: Fix invalidate_complete_page2 for THPs
mm/vmscan: Free non-shmem THPs without splitting them
mm: Fix READ_ONLY_THP warning
mm: Support arbitrary THP sizes
mm/filemap: Allow multi-page folios to be added to the page cache
mm/vmscan: Optimise shrink_page_list for smaller THPs
mm/readahead: Convert page_cache_async_ra() to take a folio
mm/readahead: Add multi-page folio readahead

Documentation/core-api/cachetlb.rst | 6 +
Documentation/core-api/mm-api.rst | 4 +
Documentation/filesystems/netfs_library.rst | 2 +
arch/nds32/include/asm/cacheflush.h | 1 +
block/bio.c | 21 +
fs/afs/write.c | 9 +-
fs/cachefiles/rdwr.c | 16 +-
fs/io_uring.c | 2 +-
fs/iomap/buffered-io.c | 524 ++++----
fs/jfs/jfs_metapage.c | 1 +
fs/remap_range.c | 116 +-
fs/xfs/xfs_aops.c | 11 +-
fs/xfs/xfs_super.c | 3 +-
include/asm-generic/cacheflush.h | 6 +
include/linux/backing-dev.h | 6 +-
include/linux/bio.h | 46 +-
include/linux/flex_proportions.h | 9 +-
include/linux/gfp.h | 22 +-
include/linux/highmem-internal.h | 11 +
include/linux/highmem.h | 38 +
include/linux/huge_mm.h | 23 +-
include/linux/ksm.h | 4 +-
include/linux/memcontrol.h | 218 ++--
include/linux/migrate.h | 4 +
include/linux/mm.h | 266 +++-
include/linux/mm_inline.h | 85 +-
include/linux/mm_types.h | 77 ++
include/linux/mmdebug.h | 20 +
include/linux/netfs.h | 77 +-
include/linux/page-flags.h | 267 ++--
include/linux/page_idle.h | 99 +-
include/linux/page_owner.h | 8 +-
include/linux/page_ref.h | 158 ++-
include/linux/pagemap.h | 615 +++++----
include/linux/rmap.h | 10 +-
include/linux/swap.h | 17 +-
include/linux/vmstat.h | 107 ++
include/linux/writeback.h | 9 +-
include/trace/events/writeback.h | 8 +-
kernel/bpf/verifier.c | 2 +-
kernel/events/uprobes.c | 3 +-
lib/flex_proportions.c | 28 +-
mm/Makefile | 2 +-
mm/compaction.c | 4 +-
mm/filemap.c | 1285 +++++++++----------
mm/folio-compat.c | 147 +++
mm/huge_memory.c | 27 +-
mm/internal.h | 40 +-
mm/khugepaged.c | 20 +-
mm/ksm.c | 34 +-
mm/memcontrol.c | 323 +++--
mm/memory-failure.c | 2 +-
mm/memory.c | 20 +-
mm/mempolicy.c | 10 +
mm/memremap.c | 2 +-
mm/migrate.c | 246 ++--
mm/mlock.c | 3 +-
mm/page-writeback.c | 447 ++++---
mm/page_alloc.c | 14 +-
mm/page_io.c | 4 +-
mm/page_owner.c | 10 +-
mm/readahead.c | 108 +-
mm/rmap.c | 14 +-
mm/shmem.c | 115 +-
mm/swap.c | 180 +--
mm/swap_state.c | 2 +-
mm/swapfile.c | 8 +-
mm/truncate.c | 193 +--
mm/userfaultfd.c | 2 +-
mm/util.c | 92 +-
mm/vmscan.c | 15 +-
mm/workingset.c | 44 +-
72 files changed, 3822 insertions(+), 2550 deletions(-)
create mode 100644 mm/folio-compat.c

--
2.30.2