Linus Torvalds 1ac5cd4978 block: don't use un-ordered __set_current_state(TASK_UNINTERRUPTIBLE) ... This mostly reverts commit 849a370016 ("block: avoid ordered task state change for polled IO"). It was wrongly claiming that the ordering wasn't necessary. The memory barrier _is_ necessary. If something is truly polling and not going to sleep, it's the whole state setting that is unnecessary, not the memory barrier. Whenever you set your state to a sleeping state, you absolutely need the memory barrier. Note that sometimes the memory barrier can be elsewhere. For example, the ordering might be provided by an external lock, or by setting the process state to sleeping before adding yourself to the wait queue list that is used for waking up (where the wait queue lock itself will guarantee that any wakeup will correctly see the sleeping state). But none of those cases were true here. NOTE! Some of the polling paths may indeed be able to drop the state setting entirely, at which point the memory barrier also goes away. (Also note that this doesn't revert the TASK_RUNNING cases: there is no race between a wakeup and setting the process state to TASK_RUNNING, since the end result doesn't depend on ordering). Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2019-01-02 10:46:03 -08:00
..
9p
adfs
affs
afs
autofs
befs
bfs
btrfs
cachefiles
ceph
cifs	4.21 merge window pull request	2018-12-28 14:57:10 -08:00
coda
configfs
cramfs
crypto
debugfs
devpts
dlm
ecryptfs
efivarfs
efs
exofs
exportfs
ext2
ext4	for-4.21/block-20181221	2018-12-28 13:19:59 -08:00
f2fs	f2fs-for-4.21-rc1	2018-12-31 09:41:37 -08:00
fat
freevxfs
fscache
fuse
gfs2
hfs
hfsplus
hostfs
hpfs
hugetlbfs	hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race	2018-12-28 12:11:52 -08:00
isofs
jbd2
jffs2
jfs
kernfs
lockd
minix
nfs
nfs_common
nfsd
nilfs2
nls
notify
ntfs
ocfs2
omfs
openpromfs
orangefs
overlayfs
proc	mm, proc: report PR_SET_THP_DISABLE in proc	2018-12-28 12:11:50 -08:00
pstore
qnx4
qnx6
quota
ramfs
reiserfs
romfs
squashfs
sysfs
sysv
tracefs
ubifs	mm: migrate: drop unused argument of migrate_page_move_mapping()	2018-12-28 12:11:51 -08:00
udf
ufs
xfs
aio.c	Merge branch 'akpm' (patches from Andrew)	2018-12-28 16:55:46 -08:00
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf.c
binfmt_elf_fdpic.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c	block: don't use un-ordered __set_current_state(TASK_UNINTERRUPTIBLE)	2019-01-02 10:46:03 -08:00
buffer.c
char_dev.c
compat.c
compat_binfmt_elf.c
compat_ioctl.c
coredump.c
d_path.c
dax.c	dax fix 4.21	2018-12-31 09:46:39 -08:00
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fhandle.c
file.c	Char/Misc driver patches for 4.21-rc1	2018-12-28 20:54:57 -08:00
file_table.c
filesystems.c
fs-writeback.c
fs_pin.c
fs_struct.c
inode.c	y2038: more syscalls and cleanups	2018-12-28 12:45:04 -08:00
internal.h
ioctl.c
iomap.c	block: don't use un-ordered __set_current_state(TASK_UNINTERRUPTIBLE)	2019-01-02 10:46:03 -08:00
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mount.h
mpage.c
namei.c
namespace.c
no-block.c
nsfs.c
open.c
pipe.c
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c
readdir.c
select.c
seq_file.c
signalfd.c
splice.c
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
userfaultfd.c	userfaultfd: clear flag if remap event not enabled	2018-12-28 12:11:51 -08:00
utimes.c
xattr.c