From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH v9 00/96] Memory folios
Date: Wed, 5 May 2021 16:04:52 +0100 [thread overview]
Message-ID: <20210505150628.111735-1-willy@infradead.org> (raw)
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. There does not appear to be a way to tell gcc
that it can cache the result of compound_head(), nor is there a way to
tell it that compound_head() is idempotent.
This patch series uses a new type, the struct folio, to manage memory.
The first 8 patches are prep work that don't involve the folio at all
but fix problems I found while working on this. Patches 9-81 introduce
infrastructure (that more than pays for itself, shrinking the kernel by
over 4kB of text). Patches 82-96 convert iomap (ie xfs) to use folios
as an example.
Git: https://git.infradead.org/users/willy/pagecache.git/shortlog/refs/tags/folio_9
v8: https://lore.kernel.org/linux-mm/20210430180740.2707166-1-willy@infradead.org/
Even more work that's not being submitted:
https://git.infradead.org/users/willy/pagecache.git/shortlog/refs/heads/folio
v9:
- Rebase onto next-20210505
- Rename folio_test_set_foo() to folio_test_set_foo_flag() (Nick Piggin)
- Rename folio_set_uptodate() to folio_mark_uptodate()
- Rename trylock_folio_flag() to folio_trylock_flag()
- Add all remaining supporting patches for iomap
- Add iomap conversion patches
Matthew Wilcox (Oracle) (96):
mm: Optimise nth_page for contiguous memmap
mm: Make __dump_page static
mm/debug: Factor PagePoisoned out of __dump_page
mm/page_owner: Constify dump_page_owner
mm: Make compound_head const-preserving
mm: Constify get_pfnblock_flags_mask and get_pfnblock_migratetype
mm: Constify page_count and page_ref_count
mm: Fix struct page layout on 32-bit systems
mm: Introduce struct folio
mm: Add folio_pgdat and folio_zone
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 flag manipulation functions
mm: Add folio_young() and folio_idle()
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_offset and folio_file_offset
mm/util: Add folio_mapping and folio_file_mapping
mm: Add folio_mapcount
mm/memcg: Add folio wrappers for various functions
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_lock_or_retry
mm/filemap: Add folio_wait_locked
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/workingset: Convert workingset_activation to take a folio
mm/swap: Add folio_activate
mm/swap: Add folio_mark_accessed
mm/rmap: Add folio_mkclean
mm: Add kmap_local_folio
mm: Add flush_dcache_folio
mm: Add arch_make_folio_accessible
mm/memcg: Remove 'page' parameter to mem_cgroup_charge_statistics
mm/memcg: Use the node id in mem_cgroup_update_tree
mm/memcg: Convert commit_charge to take a folio
mm/memcg: Add folio_charge_cgroup
mm/memcg: Add folio_uncharge_cgroup
mm/memcg: Convert mem_cgroup_track_foreign_dirty_slowpath to folio
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: Convert test_clear_page_writeback to
__folio_end_writeback
mm/writeback: Add folio_start_writeback
mm/writeback: Add folio_mark_dirty
mm/writeback: Use __set_page_dirty in __set_page_dirty_nobuffers
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
block: Add bio_add_folio
block: Add bio_for_each_folio_all
mm/lru: Add folio_lru and folio_is_file_lru
mm/workingset: Convert workingset_refault to take a folio
mm/lru: Add folio_add_lru
mm/page_alloc: Add __alloc_folio, __alloc_folio_node and alloc_folio
mm/filemap: Add filemap_alloc_folio
mm/filemap: Add folio_add_to_page_cache
mm/filemap: Convert mapping_get_entry to return a folio
mm/filemap: Add filemap_get_folio and find_get_folio
mm/filemap: Add filemap_get_stable_folio
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
Documentation/core-api/cachetlb.rst | 6 +
Documentation/core-api/mm-api.rst | 4 +
Documentation/filesystems/netfs_library.rst | 2 +
block/bio.c | 21 +
fs/afs/write.c | 9 +-
fs/buffer.c | 25 -
fs/cachefiles/rdwr.c | 16 +-
fs/io_uring.c | 2 +-
fs/iomap/buffered-io.c | 524 +++++++++-----------
fs/jfs/jfs_metapage.c | 1 +
include/asm-generic/cacheflush.h | 14 +
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/iomap.h | 2 +-
include/linux/memcontrol.h | 81 ++-
include/linux/mm.h | 226 +++++++--
include/linux/mm_inline.h | 44 +-
include/linux/mm_types.h | 75 ++-
include/linux/mmdebug.h | 23 +-
include/linux/netfs.h | 77 +--
include/linux/page-flags.h | 260 +++++++---
include/linux/page_idle.h | 99 ++--
include/linux/page_owner.h | 6 +-
include/linux/page_ref.h | 92 +++-
include/linux/pageblock-flags.h | 2 +-
include/linux/pagemap.h | 467 ++++++++++++-----
include/linux/rmap.h | 10 +-
include/linux/swap.h | 17 +-
include/linux/vmstat.h | 107 ++++
include/linux/writeback.h | 9 +-
include/net/page_pool.h | 12 +-
include/trace/events/writeback.h | 8 +-
lib/flex_proportions.c | 28 +-
mm/Makefile | 2 +-
mm/debug.c | 25 +-
mm/filemap.c | 509 +++++++++----------
mm/folio-compat.c | 107 ++++
mm/internal.h | 2 +
mm/khugepaged.c | 32 +-
mm/memcontrol.c | 100 ++--
mm/memory.c | 11 +-
mm/mempolicy.c | 10 +
mm/migrate.c | 56 +--
mm/page-writeback.c | 461 ++++++++++-------
mm/page_alloc.c | 28 +-
mm/page_io.c | 4 +-
mm/page_owner.c | 2 +-
mm/rmap.c | 12 +-
mm/swap.c | 101 ++--
mm/swap_state.c | 2 +-
mm/swapfile.c | 8 +-
mm/util.c | 60 ++-
mm/workingset.c | 44 +-
net/core/page_pool.c | 12 +-
58 files changed, 2568 insertions(+), 1421 deletions(-)
create mode 100644 mm/folio-compat.c
--
2.30.2
next reply other threads:[~2021-05-05 15:07 UTC|newest]
Thread overview: 108+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-05 15:04 Matthew Wilcox (Oracle) [this message]
2021-05-05 15:04 ` [PATCH v9 01/96] mm: Optimise nth_page for contiguous memmap Matthew Wilcox (Oracle)
2021-05-05 17:24 ` Vlastimil Babka
2021-05-05 15:04 ` [PATCH v9 02/96] mm: Make __dump_page static Matthew Wilcox (Oracle)
2021-05-05 15:04 ` [PATCH v9 03/96] mm/debug: Factor PagePoisoned out of __dump_page Matthew Wilcox (Oracle)
2021-05-05 15:04 ` [PATCH v9 04/96] mm/page_owner: Constify dump_page_owner Matthew Wilcox (Oracle)
2021-05-05 15:04 ` [PATCH v9 05/96] mm: Make compound_head const-preserving Matthew Wilcox (Oracle)
2021-05-05 15:04 ` [PATCH v9 06/96] mm: Constify get_pfnblock_flags_mask and get_pfnblock_migratetype Matthew Wilcox (Oracle)
2021-05-05 15:04 ` [PATCH v9 07/96] mm: Constify page_count and page_ref_count Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 08/96] mm: Fix struct page layout on 32-bit systems Matthew Wilcox (Oracle)
2021-05-05 17:33 ` Vlastimil Babka
2021-05-05 15:05 ` [PATCH v9 09/96] mm: Introduce struct folio Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 10/96] mm: Add folio_pgdat and folio_zone Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 11/96] mm/vmstat: Add functions to account folio statistics Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 12/96] mm/debug: Add VM_BUG_ON_FOLIO and VM_WARN_ON_ONCE_FOLIO Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 13/96] mm: Add folio reference count functions Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 14/96] mm: Add folio_put Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 15/96] mm: Add folio_get Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 16/96] mm: Add folio flag manipulation functions Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 17/96] mm: Add folio_young() and folio_idle() Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 18/96] mm: Handle per-folio private data Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 19/96] mm/filemap: Add folio_index, folio_file_page and folio_contains Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 20/96] mm/filemap: Add folio_next_index Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 21/96] mm/filemap: Add folio_offset and folio_file_offset Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 22/96] mm/util: Add folio_mapping and folio_file_mapping Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 23/96] mm: Add folio_mapcount Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 24/96] mm/memcg: Add folio wrappers for various functions Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 25/96] mm/filemap: Add folio_unlock Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 26/96] mm/filemap: Add folio_lock Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 27/96] mm/filemap: Add folio_lock_killable Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 28/96] mm/filemap: Add __folio_lock_async Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 29/96] mm/filemap: Add __folio_lock_or_retry Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 30/96] mm/filemap: Add folio_wait_locked Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 31/96] mm/swap: Add folio_rotate_reclaimable Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 32/96] mm/filemap: Add folio_end_writeback Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 33/96] mm/writeback: Add folio_wait_writeback Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 34/96] mm/writeback: Add folio_wait_stable Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 35/96] mm/filemap: Add folio_wait_bit Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 36/96] mm/filemap: Add folio_wake_bit Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 37/96] mm/filemap: Convert page wait queues to be folios Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 38/96] mm/filemap: Add folio private_2 functions Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 39/96] fs/netfs: Add folio fscache functions Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 40/96] mm: Add folio_mapped Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 41/96] mm/workingset: Convert workingset_activation to take a folio Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 42/96] mm/swap: Add folio_activate Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 43/96] mm/swap: Add folio_mark_accessed Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 44/96] mm/rmap: Add folio_mkclean Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 45/96] mm: Add kmap_local_folio Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 46/96] mm: Add flush_dcache_folio Matthew Wilcox (Oracle)
2021-05-05 23:35 ` kernel test robot
2021-05-06 2:33 ` Matthew Wilcox
2021-05-05 15:05 ` [PATCH v9 47/96] mm: Add arch_make_folio_accessible Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 48/96] mm/memcg: Remove 'page' parameter to mem_cgroup_charge_statistics Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 49/96] mm/memcg: Use the node id in mem_cgroup_update_tree Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 50/96] mm/memcg: Convert commit_charge to take a folio Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 51/96] mm/memcg: Add folio_charge_cgroup Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 52/96] mm/memcg: Add folio_uncharge_cgroup Matthew Wilcox (Oracle)
2021-05-05 20:24 ` kernel test robot
2021-05-05 15:05 ` [PATCH v9 53/96] mm/memcg: Convert mem_cgroup_track_foreign_dirty_slowpath to folio Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 54/96] mm/writeback: Rename __add_wb_stat to wb_stat_mod Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 55/96] flex_proportions: Allow N events instead of 1 Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 56/96] mm/writeback: Change __wb_writeout_inc to __wb_writeout_add Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 57/96] mm/writeback: Convert test_clear_page_writeback to __folio_end_writeback Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 58/96] mm/writeback: Add folio_start_writeback Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 59/96] mm/writeback: Add folio_mark_dirty Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 60/96] mm/writeback: Use __set_page_dirty in __set_page_dirty_nobuffers Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 61/96] mm/writeback: Add __folio_mark_dirty Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 62/96] mm/writeback: Add filemap_dirty_folio Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 63/96] mm/writeback: Add folio_account_cleaned Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 64/96] mm/writeback: Add folio_cancel_dirty Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 65/96] mm/writeback: Add folio_clear_dirty_for_io Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 66/96] mm/writeback: Add folio_account_redirty Matthew Wilcox (Oracle)
2021-05-05 15:05 ` [PATCH v9 67/96] mm/writeback: Add folio_redirty_for_writepage Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 68/96] mm/filemap: Add i_blocks_per_folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 69/96] mm/filemap: Add folio_mkwrite_check_truncate Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 70/96] mm/filemap: Add readahead_folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 71/96] block: Add bio_add_folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 72/96] block: Add bio_for_each_folio_all Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 73/96] mm/lru: Add folio_lru and folio_is_file_lru Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 74/96] mm/workingset: Convert workingset_refault to take a folio Matthew Wilcox (Oracle)
2021-05-05 20:17 ` kernel test robot
2021-05-05 20:57 ` Matthew Wilcox
2021-05-05 15:06 ` [PATCH v9 75/96] mm/lru: Add folio_add_lru Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 76/96] mm/page_alloc: Add __alloc_folio, __alloc_folio_node and alloc_folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 77/96] mm/filemap: Add filemap_alloc_folio Matthew Wilcox (Oracle)
2021-05-06 0:00 ` kernel test robot
2021-05-06 2:28 ` Matthew Wilcox
2021-05-05 15:06 ` [PATCH v9 78/96] mm/filemap: Add folio_add_to_page_cache Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 79/96] mm/filemap: Convert mapping_get_entry to return a folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 80/96] mm/filemap: Add filemap_get_folio and find_get_folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 81/96] mm/filemap: Add filemap_get_stable_folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 82/96] iomap: Convert to_iomap_page to take a folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 83/96] iomap: Convert iomap_page_create " Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 84/96] iomap: Convert iomap_page_release " Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 85/96] iomap: Convert iomap_releasepage to use " Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 86/96] iomap: Convert iomap_invalidatepage " Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 87/96] iomap: Pass the iomap_page into iomap_set_range_uptodate Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 88/96] iomap: Use folio offsets instead of page offsets Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 89/96] iomap: Convert bio completions to use folios Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 90/96] iomap: Convert readahead and readpage to use a folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 91/96] iomap: Convert iomap_page_mkwrite " Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 92/96] iomap: Convert iomap_write_begin and iomap_write_end to folios Matthew Wilcox (Oracle)
2021-05-05 21:36 ` kernel test robot
2021-05-05 22:10 ` Matthew Wilcox
2021-05-05 15:06 ` [PATCH v9 93/96] iomap: Convert iomap_read_inline_data to take a folio Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 94/96] iomap: Convert iomap_write_end_inline " Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 95/96] iomap: Convert iomap_add_to_ioend " Matthew Wilcox (Oracle)
2021-05-05 15:06 ` [PATCH v9 96/96] iomap: Convert iomap_do_writepage to use " Matthew Wilcox (Oracle)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210505150628.111735-1-willy@infradead.org \
--to=willy@infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).