John Stultz 295f3fcaa8 pstore: Revert pmsg_lock back to a normal mutex ... [ Upstream commit 5239a89b06 ] This reverts commit 76d62f24db. So while priority inversion on the pmsg_lock is an occasional problem that an rt_mutex would help with, in uses where logging is writing to pmsg heavily from multiple threads, the pmsg_lock can be heavily contended. After this change landed, it was reported that cases where the mutex locking overhead was commonly adding on the order of 10s of usecs delay had suddenly jumped to ~msec delay with rtmutex. It seems the slight differences in the locks under this level of contention causes the normal mutexes to utilize the spinning optimizations, while the rtmutexes end up in the sleeping slowpath (which allows additional threads to pile on trying to take the lock). In this case, it devolves to a worse case senerio where the lock acquisition and scheduling overhead dominates, and each thread is waiting on the order of ~ms to do ~us of work. Obviously, having tons of threads all contending on a single lock for logging is non-optimal, so the proper fix is probably reworking pstore pmsg to have per-cpu buffers so we don't have contention. Additionally, Steven Rostedt has provided some furhter optimizations for rtmutexes that improves the rtmutex spinning path, but at least in my testing, I still see the test tripping into the sleeping path on rtmutexes while utilizing the spinning path with mutexes. But in the short term, lets revert the change to the rt_mutex and go back to normal mutexes to avoid a potentially major performance regression. And we can work on optimizations to both rtmutexes and finer-grained locking for pstore pmsg in the future. Cc: Wei Wang <wvw@google.com> Cc: Midas Chien<midaschieh@google.com> Cc: "Chunhui Li (李春辉)" <chunhui.li@mediatek.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Kees Cook <keescook@chromium.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tony Luck <tony.luck@intel.com> Cc: kernel-team@android.com Fixes: 76d62f24db ("pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion") Reported-by: "Chunhui Li (李春辉)" <chunhui.li@mediatek.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230308204043.2061631-1-jstultz@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>		2023-05-11 23:00:31 +09:00
..
9p	9p: fix a bunch of checkpatch warnings	2022-08-17 14:24:07 +02:00
adfs	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
affs	affs: initialize fsdata in affs_truncate()	2023-02-01 08:27:06 +01:00
afs	afs: Fix lost servers_outstanding count	2022-12-31 13:14:45 +01:00
autofs	autofs: fix wait name hash calculation in autofs_wait()	2021-10-20 21:09:02 -04:00
befs	isystem: ship and use stdarg.h	2021-08-19 09:02:55 +09:00
bfs	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
btrfs	btrfs: fix fast csum implementation detection	2023-04-20 12:13:52 +02:00
cachefiles	fs: add is_idmapped_mnt() helper	2022-07-02 16:41:14 +02:00
ceph	ceph: update the time stamps and try to drop the suid/sgid	2023-03-10 09:40:08 +01:00
cifs	cifs: sanitize paths in cifs_update_super_prepath.	2023-04-13 16:48:24 +02:00
coda	coda: Avoid partial allocation of sig_inputArgs	2023-03-10 09:39:50 +01:00
configfs	configfs: fix possible memory leak in configfs_create_dir()	2022-12-31 13:14:15 +01:00
cramfs	…
crypto	fscrypt: fix keyring memory leak on mount failure	2022-11-10 18:15:37 +01:00
debugfs	debugfs: fix error when writing negative value to atomic_t debugfs file	2022-12-31 13:14:03 +01:00
devpts	fsnotify: fix fsnotify hooks in pseudo filesystems	2022-02-01 17:27:01 +01:00
dlm	fs: dlm: start midcomms before scand	2023-03-17 08:48:50 +01:00
ecryptfs	fs: add is_idmapped_mnt() helper	2022-07-02 16:41:14 +02:00
efivarfs	…
efs	…
erofs	erofs: fix potential overflow calculating xattr_isize	2023-05-11 23:00:20 +09:00
exfat	exfat: fix inode->i_blocks for non-512 byte sector size device	2023-03-10 09:39:58 +01:00
exportfs	exportfs: support idmapped mounts	2022-06-09 10:23:32 +02:00
ext2	ext2: Use kvmalloc() for group descriptor array	2022-10-26 12:35:51 +02:00
ext4	ext4: use ext4_journal_start/stop for fast commit transactions	2023-05-11 23:00:16 +09:00
f2fs	f2fs: fix to avoid use-after-free for cached IPU bio	2023-05-11 23:00:27 +09:00
fat	fat: add ratelimit to fat*_ent_bread()	2022-06-09 10:22:42 +02:00
freevxfs	…
fscache	fscache: Remove an unused static variable	2021-10-04 22:13:12 +01:00
fuse	fuse: fix deadlock between atomic O_TRUNC and page invalidation	2023-04-26 13:51:54 +02:00
gfs2	gfs2: Improve gfs2_make_fs_rw error handling	2023-03-10 09:39:53 +01:00
hfs	hfs: fix missing hfs_bnode_get() in __hfs_bnode_create	2023-03-10 09:39:57 +01:00
hfsplus	fs: hfsplus: fix UAF issue in hfsplus_put_super	2023-03-10 09:39:57 +01:00
hostfs	hostfs: support splice_write	2021-08-26 22:28:02 +02:00
hpfs	hpfs: use iomap_fiemap to implement ->fiemap	2021-07-27 11:00:36 +02:00
hugetlbfs	hugetlbfs: fix null-ptr-deref in hugetlbfs_parse_param()	2022-12-31 13:14:44 +01:00
iomap	iomap: iomap_write_failed fix	2022-06-09 10:22:55 +02:00
isofs	isofs: Fix out of bound access for corrupted isofs image	2021-11-12 15:05:50 +01:00
jbd2	jdb2: Don't refuse invalidation of already invalidated buffers	2023-05-11 23:00:29 +09:00
jffs2	jffs2: correct logic when creating a hole in jffs2_write_begin	2023-03-22 13:31:30 +01:00
jfs	fs/jfs: fix shift exponent db_agl2size negative	2023-03-11 13:57:22 +01:00
kernfs	kernfs: fix use-after-free in __kernfs_remove	2022-11-03 23:59:13 +09:00
ksmbd	ksmbd: fix memleak in session setup	2023-05-11 23:00:18 +09:00
lockd	lockd: set file_lock start and end when decoding nlm4 testargs	2023-03-30 12:47:56 +02:00
minix	minix: fix bug when opening a file with O_DIRECT	2022-04-13 20:59:10 +02:00
netfs	netfs: fix parameter of cleanup()	2021-12-29 12:28:59 +01:00
nfs	NFSv4: Fix hangs when recovering open state after a server reboot	2023-04-05 11:25:00 +02:00
nfs_common	nfs: Fix kerneldoc warning shown up by W=1	2021-10-04 22:02:17 +01:00
nfsd	NFSD: callback request does not use correct credential for AUTH_SYS	2023-04-13 16:48:19 +02:00
nilfs2	nilfs2: initialize unused bytes in segment summary blocks	2023-04-26 13:51:51 +02:00
nls	…
notify	fsnotify: fix wrong lockdep annotations	2022-06-09 10:22:50 +02:00
ntfs	ntfs: check overflow when iterating ATTR_RECORDs	2022-11-26 09:24:52 +01:00
ntfs3	fs/ntfs3: Validate attribute data and valid sizes	2023-02-09 11:26:47 +01:00
ocfs2	ocfs2: fix freeing uninitialized resource on ocfs2_dlm_shutdown	2023-04-13 16:48:26 +02:00
omfs	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
openpromfs	…
orangefs	orangefs: Fix kmemleak in orangefs_{kernel,client}_debug_init()	2022-12-31 13:14:44 +01:00
overlayfs	ovl: Use "buf" flexible array for memcpy() destination	2023-02-09 11:26:47 +01:00
proc	mm: hugetlb: proc: check for hugetlb shared PMD in /proc/PID/smaps	2023-02-09 11:26:44 +01:00
pstore	pstore: Revert pmsg_lock back to a normal mutex	2023-05-11 23:00:31 +09:00
qnx4	qnx4: work around gcc false positive warning bug	2021-09-21 08:36:48 -07:00
qnx6	…
quota	ext4: fix bug_on in __es_tree_search caused by bad quota inode	2023-01-12 11:59:01 +01:00
ramfs	fs: move ramfs_aops to libfs	2021-06-29 10:53:48 -07:00
reiserfs	reiserfs: Add security prefix to xattr name in reiserfs_security_write()	2023-05-11 23:00:17 +09:00
romfs	…
smbfs_common	cifs: Fix crash on unload of cifs_arc4.ko	2021-12-14 10:57:12 +01:00
squashfs	revert "squashfs: harden sanity check in squashfs_read_xattr_id_table"	2023-02-22 12:57:07 +01:00
sysfs	sysfs: Allow deferred execution of iomem_get_mapping()	2021-08-06 13:05:28 +02:00
sysv	fs: sysv: Fix sysv_nblocks() returns wrong value	2022-12-31 13:14:05 +01:00
tracefs	tracefs: Only clobber mode/uid/gid on remount if asked	2022-09-20 12:39:43 +02:00
ubifs	ubifs: Free memory for tmpfile name	2023-05-11 23:00:18 +09:00
udf	udf: Fix off-by-one error when discarding preallocation	2023-03-17 08:48:50 +01:00
ufs	isystem: ship and use stdarg.h	2021-08-19 09:02:55 +09:00
unicode	…
vboxsf	vboxfs: fix broken legacy mount signature checking	2021-09-27 11:26:21 -07:00
verity	fsverity: don't drop pagecache at end of FS_IOC_ENABLE_VERITY	2023-04-05 11:24:51 +02:00
xfs	xfs: don't consider future format versions valid	2023-05-11 23:00:18 +09:00
zonefs	zonefs: Fix error message in zonefs_file_dio_append()	2023-04-05 11:25:01 +02:00
Kconfig	4 cifs/smb3 fixes, one for DFS reconnect, and one to begin creating common headers for server and client and the other two to rename the cifs_common directory to smbfs_common to be more consistent ie change use of the name cifs to smb which is more accurate	2021-09-12 10:10:21 -07:00
Kconfig.binfmt	binfmt: remove support for em86 (alpha only)	2021-07-25 22:33:03 -07:00
Makefile	io_uring: move to separate directory	2022-12-14 11:37:31 +01:00
aio.c	aio: fix mremap after fork null-deref	2023-02-22 12:57:05 +01:00
anon_inodes.c	…
attr.c	attr: use consistent sgid stripping checks	2023-03-17 08:49:01 +01:00
bad_inode.c	vfs: add rcu argument to ->get_acl() callback	2021-08-18 22:08:24 +02:00
binfmt_aout.c	binfmt: a.out: Fix bogus semicolon	2021-09-05 10:15:05 -07:00
binfmt_elf.c	fs/binfmt_elf: Fix memory leak in load_elf_binary()	2022-11-03 23:59:12 +09:00
binfmt_elf_fdpic.c	binfmt: Fix error return code in load_elf_fdpic_binary()	2023-01-12 11:58:46 +01:00
binfmt_flat.c	binfmt_flat: do not stop relocating GOT entries prematurely on riscv	2022-06-09 10:22:26 +02:00
binfmt_misc.c	binfmt_misc: fix shift-out-of-bounds in check_special_flags	2022-12-31 13:14:39 +01:00
binfmt_script.c	…
buffer.c	mm: fs: initialize fsdata passed to write_begin/write_end interface	2022-11-26 09:24:51 +01:00
char_dev.c	chardev: fix error handling in cdev_device_add()	2022-12-31 13:14:30 +01:00
compat_binfmt_elf.c	…
coredump.c	coredump: Use the vma snapshot in fill_files_note	2022-04-08 14:24:18 +02:00
d_path.c	d_path: make 'prepend()' fill up the buffer exactly on overflow	2021-09-02 10:07:29 -07:00
dax.c	fsdax: Fix infinite loop in dax_iomap_rw()	2022-09-28 11:11:56 +02:00
dcache.c	…
direct-io.c	…
drop_caches.c	fs: drop_caches: fix skipping over shadow cache inodes	2021-09-03 09:58:10 -07:00
eventfd.c	eventfd: provide a eventfd_signal_mask() helper	2023-01-24 07:22:43 +01:00
eventpoll.c	eventpoll: add EPOLL_URING_WAKE poll wakeup flag	2023-01-24 07:22:43 +01:00
exec.c	exec: Copy oldsighand->action under spin-lock	2022-11-03 23:59:12 +09:00
fcntl.c	Merge branch 'akpm' (patches from Andrew)	2021-09-03 10:08:28 -07:00
fhandle.c	…
file.c	fs: prevent out-of-bounds array speculation when closing a file descriptor	2023-03-17 08:48:47 +01:00
file_table.c	locks: fix TOCTOU race when granting write lease	2022-10-26 12:34:58 +02:00
filesystems.c	fs: simplify get_filesystem_list / get_all_fs_names	2021-08-23 01:25:40 -04:00
fs-writeback.c	writeback, cgroup: fix null-ptr-deref write in bdi_split_work_to_wbs	2023-05-11 23:00:18 +09:00
fs_context.c	vfs: fs_context: fix up param length parsing in legacy_parse_param	2022-01-20 09:13:14 +01:00
fs_parser.c	namei: Standardize callers of filename_lookup()	2021-09-07 16:07:47 -04:00
fs_pin.c	…
fs_struct.c	…
fs_types.c	…
fsopen.c	…
init.c	…
inode.c	attr: use consistent sgid stripping checks	2023-03-17 08:49:01 +01:00
internal.h	attr: use consistent sgid stripping checks	2023-03-17 08:49:01 +01:00
ioctl.c	fs: fix an infinite loop in iomap_fiemap	2022-05-25 09:57:26 +02:00
kernel_read_file.c	vfs: check fd has read access in kernel_read_file_from_fd()	2021-10-18 20:22:03 -10:00
libfs.c	libfs: add DEFINE_SIMPLE_ATTRIBUTE_SIGNED for signed value	2022-12-31 13:14:03 +01:00
locks.c	filelocks: use mount idmapping for setlease permission check	2023-03-17 08:49:02 +01:00
mbcache.c	mbcache: Avoid nesting of cache->c_list_lock under bit locks	2023-01-12 11:59:20 +01:00
mount.h	…
mpage.c	…
namei.c	fs: move S_ISGID stripping into the vfs_*() helpers	2023-03-17 08:49:00 +01:00
namespace.c	fs: drop peer group ids under namespace lock	2023-04-13 16:48:25 +02:00
no-block.c	…
nsfs.c	…
open.c	attr: use consistent sgid stripping checks	2023-03-17 08:49:01 +01:00
pipe.c	pipe: Fix missing lock in pipe_resize_ring()	2022-06-06 08:43:37 +02:00
pnode.c	pnode: terminate at peers of source	2023-01-12 11:58:47 +01:00
pnode.h	…
posix_acl.c	fs: fix acl translation	2022-07-02 16:41:17 +02:00
proc_namespace.c	fs: add is_idmapped_mnt() helper	2022-07-02 16:41:14 +02:00
read_write.c	vfs: fix copy_file_range() averts filesystem freeze protection	2022-12-19 12:36:39 +01:00
readdir.c	…
remap_range.c	fs/remap: constrain dedupe of EOF blocks	2022-07-21 21:24:14 +02:00
select.c	select: Fix indefinitely sleeping task in poll_schedule_timeout()	2022-01-29 10:58:25 +01:00
seq_file.c	rxrpc: Fix locking issue	2022-07-12 16:35:08 +02:00
signalfd.c	signalfd: use wake_up_pollfree()	2021-12-14 10:57:15 +01:00
splice.c	Revert "fs: check FMODE_LSEEK to control internal pipe splicing"	2022-10-26 12:34:17 +02:00
stack.c	…
stat.c	stat: fix inconsistency between struct stat and struct compat_stat	2022-04-27 14:38:57 +02:00
statfs.c	…
super.c	fscrypt: destroy keyring after security_sb_delete()	2023-03-30 12:47:56 +02:00
sync.c	vfs: make sync_filesystem return errors from ->sync_fs	2022-04-27 14:38:50 +02:00
timerfd.c	timerfd: Provide timerfd_resume()	2021-08-10 17:57:22 +02:00
userfaultfd.c	userfaultfd: open userfaultfds with O_RDONLY	2022-10-26 12:34:36 +02:00
utimes.c	…
xattr.c	fs: don't audit the capability check in simple_xattr_list()	2022-12-31 13:14:01 +01:00