linux/fs
Hao Xu 4e86a2c980 io_uring: implement multishot mode for accept
Refactor io_accept() to support multishot mode.

theoretical analysis:
  1) when connections come in fast
    - singleshot:
              add accept sqe(userspace) --> accept inline
                              ^                 |
                              |-----------------|
    - multishot:
             add accept sqe(userspace) --> accept inline
                                              ^     |
                                              |--*--|

    we do accept repeatedly in * place until get EAGAIN

  2) when connections come in at a low pressure
    similar thing like 1), we reduce a lot of userspace-kernel context
    switch and useless vfs_poll()

tests:
Did some tests, which goes in this way:

  server    client(multiple)
  accept    connect
  read      write
  write     read
  close     close

Basically, raise up a number of clients(on same machine with server) to
connect to the server, and then write some data to it, the server will
write those data back to the client after it receives them, and then
close the connection after write return. Then the client will read the
data and then close the connection. Here I test 10000 clients connect
one server, data size 128 bytes. And each client has a go routine for
it, so they come to the server in short time.
test 20 times before/after this patchset, time spent:(unit cycle, which
is the return value of clock())
before:
  1930136+1940725+1907981+1947601+1923812+1928226+1911087+1905897+1941075
  +1934374+1906614+1912504+1949110+1908790+1909951+1941672+1969525+1934984
  +1934226+1914385)/20.0 = 1927633.75
after:
  1858905+1917104+1895455+1963963+1892706+1889208+1874175+1904753+1874112
  +1874985+1882706+1884642+1864694+1906508+1916150+1924250+1869060+1889506
  +1871324+1940803)/20.0 = 1894750.45

(1927633.75 - 1894750.45) / 1927633.75 = 1.65%

Signed-off-by: Hao Xu <howeyxu@tencent.com>
Link: https://lore.kernel.org/r/20220514142046.58072-5-haoxu.linux@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-14 08:34:22 -06:00
..
9p Netfs prep for write helpers 2022-03-31 15:49:36 -07:00
adfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
affs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
afs fscache: Remove the cookie parameter from fscache_clear_page_bits() 2022-04-08 23:54:37 +01:00
autofs
befs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
bfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
btrfs for-5.18-rc2-tag 2022-04-14 10:58:27 -07:00
cachefiles cachefiles: Fix KASAN slab-out-of-bounds in cachefiles_set_volume_xattr 2022-04-08 23:32:40 +01:00
ceph Filesystem/VFS changes for 5.18, part two 2022-04-01 13:50:50 -07:00
cifs cifs: destage any unwritten data to the server before calling copychunk_write 2022-04-20 22:54:54 -05:00
coda Folio changes for 5.18 2022-03-22 17:03:12 -07:00
configfs configfs: fix a race in configfs_{,un}register_subsystem() 2022-02-22 18:30:28 +01:00
cramfs
crypto fs: Remove ->readpages address space operation 2022-04-01 13:45:33 -04:00
debugfs debugfs: Document that debugfs_create functions need not be error checked 2022-02-25 11:56:13 +01:00
devpts fsnotify: fix fsnotify hooks in pseudo filesystems 2022-01-24 14:17:02 +01:00
dlm driver core changes for 5.17-rc1 2022-01-12 11:11:34 -08:00
ecryptfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
efivarfs
efs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
erofs erofs: fix use-after-free of on-stack io[] 2022-04-15 23:51:43 +08:00
exfat Description for this pull request: 2022-04-01 14:20:24 -07:00
exportfs
ext2 \n 2022-03-25 17:38:15 -07:00
ext4 Fix some syzbot-detected bugs, as well as other bugs found by I/O 2022-04-22 18:18:27 -07:00
f2fs f2fs: Get the superblock from the mapping instead of the page 2022-04-01 14:40:44 -04:00
fat Merge branch 'akpm' (patches from Andrew) 2022-03-24 14:14:07 -07:00
freevxfs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
fscache fscache: remove FSCACHE_OLD_API Kconfig option 2022-04-08 23:54:37 +01:00
fuse fs: Remove ->readpages address space operation 2022-04-01 13:45:33 -04:00
gfs2 gfs2 fixes 2022-03-31 15:57:50 -07:00
hfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
hfsplus Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
hostfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
hpfs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
hugetlbfs mm, hugetlb: allow for "high" userspace addresses 2022-04-21 20:01:09 -07:00
iomap iomap: Simplify is_partially_uptodate a little 2022-04-01 14:40:43 -04:00
isofs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
jbd2 Fix some syzbot-detected bugs, as well as other bugs found by I/O 2022-04-22 18:18:27 -07:00
jffs2 This pull request contains fixes for JFFS2, UBI and UBIFS 2022-03-31 16:09:41 -07:00
jfs A couple bug fixes 2022-03-29 18:17:30 -07:00
kernfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
ksmbd ksmbd: set fixed sector size to FS_SECTOR_SIZE_INFORMATION 2022-04-14 20:56:13 -05:00
lockd NFSD: Move svc_serv_ops::svo_function into struct svc_serv 2022-02-28 10:26:40 -05:00
minix Merge branch 'akpm' (patches from Andrew) 2022-03-24 14:14:07 -07:00
netfs netfs: Split some core bits out into their own file 2022-03-18 09:29:05 +00:00
nfs NFS client bugfixes for Linux 5.18 2022-04-08 07:39:17 -10:00
nfs_common
nfsd NFSD bug fixes for 5.18-rc: 2022-04-12 14:23:19 -10:00
nilfs2 nilfs2: get rid of nilfs_mapping_init() 2022-04-01 11:46:09 -07:00
nls
notify fsnotify: remove redundant parameter judgment 2022-03-14 09:05:25 +01:00
ntfs ntfs: Correct mark_ntfs_record_dirty() folio conversion 2022-04-01 14:40:44 -04:00
ntfs3 Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
ocfs2 ocfs2: fix crash when mount with quota enabled 2022-04-01 11:46:09 -07:00
omfs fs: Convert __set_page_dirty_buffers to block_dirty_folio 2022-03-16 13:37:04 -04:00
openpromfs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
orangefs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
overlayfs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
proc Updates to Tracing: 2022-04-03 12:26:01 -07:00
pstore pstore: Don't use semaphores in always-atomic-context code 2022-03-15 11:08:23 -07:00
qnx4 fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
qnx6 fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
quota quota: make dquot_quota_sync return errors from ->sync_fs 2022-01-30 08:59:47 -08:00
ramfs
reiserfs \n 2022-03-25 17:38:15 -07:00
romfs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
smbfs_common smb3: fix ksmbd bigendian bug in oplock break, and move its struct to smbfs_common 2022-03-31 09:38:53 -05:00
squashfs Merge branch 'akpm' (patches from Andrew) 2022-03-22 16:11:53 -07:00
sysfs kobject: kobj_type: remove default_attrs 2022-04-05 15:39:19 +02:00
sysv Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
tracefs tracefs: Set the group ownership in apply_options() not parse_options() 2022-02-25 21:05:04 -05:00
ubifs This pull request contains fixes for JFFS2, UBI and UBIFS 2022-03-31 16:09:41 -07:00
udf \n 2022-03-25 17:38:15 -07:00
ufs Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
unicode kbuild: unify cmd_copy and cmd_shipped 2022-02-14 10:37:32 +09:00
vboxsf Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
verity fs: Remove ->readpages address space operation 2022-04-01 13:45:33 -04:00
xfs Bug fixes for 5.18: 2022-04-01 19:30:44 -07:00
zonefs for-5.18/write-streams-2022-03-18 2022-03-26 11:51:46 -07:00
aio.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c coredump: Snapshot the vmas in do_coredump 2022-03-08 12:55:29 -06:00
binfmt_elf_test.c binfmt_elf: Introduce KUnit test 2022-03-03 20:38:56 -08:00
binfmt_elf.c revert "fs/binfmt_elf: use PT_LOAD p_align values for static PIE" 2022-04-15 14:49:56 -07:00
binfmt_flat.c coredump: Don't compile flat_core_dump when coredumps are disabled 2022-03-09 10:37:07 -06:00
binfmt_misc.c Fix regression due to "fs: move binfmt_misc sysctl to its own file" 2022-02-09 09:50:02 -08:00
binfmt_script.c
buffer.c filemap: Remove AOP_FLAG_CONT_EXPAND 2022-04-01 14:40:44 -04:00
char_dev.c
compat_binfmt_elf.c binfmt_elf: Introduce KUnit test 2022-03-03 20:38:56 -08:00
coredump.c ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
d_path.c
dax.c dax for 5.18 2022-03-24 18:12:09 -07:00
dcache.c mm: dcache: use kmem_cache_alloc_lru() to allocate dentry 2022-03-22 15:57:03 -07:00
direct-io.c block: remove the per-bio/request write hint 2022-03-07 12:45:57 -07:00
drop_caches.c
eventfd.c
eventpoll.c eventpoll: simplify sysctl declaration with register_sysctl() 2022-01-22 08:33:35 +02:00
exec.c ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
fcntl.c fs: remove fs.f_write_hint 2022-03-08 17:55:03 -07:00
fhandle.c
file_table.c SUNRPC: Ensure we flush any closed sockets before xs_xprt_free() 2022-04-07 16:19:47 -04:00
file.c fs: fix fd table size alignment properly 2022-03-29 23:29:18 -07:00
filesystems.c
fs_context.c vfs: fs_context: fix up param length parsing in legacy_parse_param 2022-01-18 09:23:19 +02:00
fs_parser.c
fs_pin.c
fs_struct.c
fs_types.c
fs-writeback.c Merge branch 'akpm' (patches from Andrew) 2022-03-22 16:11:53 -07:00
fsopen.c
init.c
inode.c fs: introduce alloc_inode_sb() to allocate filesystems specific inode 2022-03-22 15:57:03 -07:00
internal.h Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
io_uring.c io_uring: implement multishot mode for accept 2022-05-14 08:34:22 -06:00
io-wq.c io-wq: use __set_notify_signal() to wake workers 2022-04-30 08:39:54 -06:00
io-wq.h io_uring: add support for IORING_ASYNC_CANCEL_ALL 2022-04-24 18:18:18 -06:00
ioctl.c Fixes for 5.18-rc1: 2022-04-01 19:35:56 -07:00
Kconfig Folio changes for 5.18 2022-03-22 17:03:12 -07:00
Kconfig.binfmt execve updates for v5.18-rc1 2022-03-21 19:16:02 -07:00
kernel_read_file.c
libfs.c fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio 2022-03-16 13:37:05 -04:00
locks.c fs: move locking sysctls where they are used 2022-01-22 08:33:36 +02:00
Makefile Fix from Christoph Hellwig merging the CONFIG_UNICODE_UTF8_DATA into the 2022-02-01 11:13:24 -08:00
mbcache.c
mount.h
mpage.c for-5.18/alloc-cleanups-2022-03-25 2022-03-26 11:59:30 -07:00
namei.c VFS: filename_create(): fix incorrect intent. 2022-04-14 15:53:43 -07:00
namespace.c fs: unset MNT_WRITE_HOLD on failure 2022-04-21 17:57:37 +02:00
no-block.c
nsfs.c
open.c fs: remove fs.f_write_hint 2022-03-08 17:55:03 -07:00
pipe.c Revert "fs/pipe: use kvcalloc to allocate a pipe_buffer array" 2022-04-20 12:07:53 -07:00
pnode.c
pnode.h
posix_acl.c fs: fix acl translation 2022-04-19 10:19:02 -07:00
proc_namespace.c
read_write.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
readdir.c
remap_range.c Filesystem folio changes for 5.18 2022-03-22 18:26:56 -07:00
select.c select: Fix indefinitely sleeping task in poll_schedule_timeout() 2022-01-11 09:03:05 -08:00
seq_file.c seq_file: fix NULL pointer arithmetic warning 2022-02-01 11:31:55 -05:00
signalfd.c Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2022-01-17 05:49:30 +02:00
splice.c mm: Convert remove_mapping() to take a folio 2022-03-21 12:59:01 -04:00
stack.c
stat.c stat: fix inconsistency between struct stat and struct compat_stat 2022-04-12 13:35:08 -10:00
statfs.c
super.c vfs: make freeze_super abort when sync_filesystem returns error 2022-01-30 08:59:47 -08:00
sync.c vfs: make sync_filesystem return errors from ->sync_fs 2022-01-30 08:59:47 -08:00
sysctls.c fs: move namespace sysctls and declare fs base directory 2022-01-22 08:33:36 +02:00
timerfd.c
userfaultfd.c userfaultfd: provide unmasked address on page-fault 2022-03-22 15:57:08 -07:00
utimes.c
xattr.c fs: fix acl translation 2022-04-19 10:19:02 -07:00