linux/kernel
Peter Zijlstra 0abf17bc77 sched/swait: Switch to full exclusive mode
Linus noted that swait basically implements exclusive mode -- because
swake_up() only wakes a single waiter. And because of that it should
take care to properly deal with the interruptible case.

In short, the problem is that swake_up() can race with a signal. In
this this case it is possible the swake_up() 'wakes' the waiter that
is already on the way out because it just got a signal and the wakeup
gets lost.

The normal wait code is very careful and avoids this situation, make
sure we do too.

Copy the exact exclusive semantics from wait.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: bigeasy@linutronix.de
Cc: oleg@redhat.com
Cc: paulmck@linux.vnet.ibm.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180612083909.209762413@infradead.org
2018-06-20 11:35:56 +02:00
..
bpf Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-06-16 07:39:34 +09:00
cgroup docs: Fix some broken references 2018-06-15 18:10:01 -03:00
configs kconfig: tinyconfig: remove stale stack protector fixups 2018-06-15 07:15:28 +09:00
debug treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
events treewide: kzalloc_node() -> kcalloc_node() 2018-06-12 16:19:22 -07:00
gcov gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT 2018-06-08 18:56:02 +09:00
irq Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 09:44:53 -07:00
livepatch livepatch: Allow to call a custom callback when freeing shadow variables 2018-04-17 13:42:48 +02:00
locking treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
power fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
printk Printk changes for 4.18 2018-06-06 16:04:55 -07:00
rcu treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
sched sched/swait: Switch to full exclusive mode 2018-06-20 11:35:56 +02:00
time Power management updates for 4.18-rc1 2018-06-05 09:38:39 -07:00
trace docs: Fix some broken references 2018-06-15 18:10:01 -03:00
.gitignore
acct.c kernel/acct.c: fix the acct->needcheck check in check_free_space() 2018-01-04 16:45:09 -08:00
async.c kernel/async.c: revert "async: simplify lowest_in_progress()" 2018-02-06 18:32:44 -08:00
audit_fsnotify.c fsnotify: add fsnotify_add_inode_mark() wrappers 2018-05-18 14:58:22 +02:00
audit_tree.c fsnotify: add fsnotify_add_inode_mark() wrappers 2018-05-18 14:58:22 +02:00
audit_watch.c \n 2018-06-17 05:06:18 +09:00
audit.c audit: use inline function to get audit context 2018-05-14 17:24:18 -04:00
audit.h audit: track the owner of the command mutex ourselves 2018-02-23 11:22:22 -05:00
auditfilter.c audit: use existing session info function 2018-05-18 15:47:54 -04:00
auditsc.c audit: Fix wrong task in comparison of session ID 2018-05-21 14:27:43 -04:00
backtracetest.c
bounds.c
capability.c
compat.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00
configs.c
context_tracking.c
cpu_pm.c
cpu.c cpu/hotplug: Fix unused function warning 2018-03-15 20:34:40 +01:00
crash_core.c mm: split page_type out from _mapcount 2018-06-07 17:34:37 -07:00
crash_dump.c
cred.c
delayacct.c delayacct: Use raw_spinlocks 2018-04-27 14:34:51 +02:00
dma.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
elfcore.c
exec_domain.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
exit.c kernel: use kernel_wait4() instead of sys_wait4() 2018-04-02 20:14:51 +02:00
extable.c extable: Make init_kernel_text() global 2018-02-21 16:54:06 +01:00
fail_function.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
fork.c mm: check for SIGKILL inside dup_mmap() loop 2018-06-15 07:55:24 +09:00
freezer.c
futex_compat.c
futex.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
groups.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
hung_task.c kernel/hung_task.c: show all hung tasks before panic 2018-06-07 17:34:39 -07:00
iomem.c memremap: split devm_memremap_pages() and memremap() infrastructure 2018-05-15 23:08:33 -07:00
irq_work.c irq/work: Improve the flag definitions 2018-01-08 19:43:15 +01:00
jump_label.c jump_label: Disable jump labels in __exit code 2018-03-20 08:57:17 +01:00
kallsyms.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c sched/core / kcov: avoid kcov_area during task switch 2018-06-15 07:55:24 +09:00
kexec_core.c kexec: yield to scheduler when loading kimage segments 2018-06-15 07:55:24 +09:00
kexec_file.c treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
kexec_internal.h
kexec.c kexec: call do_kexec_load() in compat syscall directly 2018-04-02 20:15:01 +02:00
kmod.c
kprobes.c kprobes: Fix random address output of blacklist file 2018-04-25 10:27:56 -04:00
ksysfs.c
kthread.c kthread: Allow kthread_park() on a parked kthread 2018-05-25 08:03:51 +02:00
latencytop.c
Makefile Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 10:17:09 -07:00
memremap.c mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS 2018-05-22 06:59:39 -07:00
module_signing.c
module-internal.h
module.c Modules updates for v4.18 2018-06-16 07:36:39 +09:00
notifier.c
nsproxy.c
padata.c padata: add SPDX identifier 2018-01-05 18:43:00 +11:00
panic.c Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables 2018-06-14 12:21:18 +09:00
params.c kernel/params.c: downgrade warning for unsafe parameters 2018-04-11 10:28:37 -07:00
pid_namespace.c Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-04-03 19:15:32 -07:00
pid.c xarray: add the xa_lock to the radix_tree_root 2018-04-11 10:28:39 -07:00
profile.c
ptrace.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
range.c
reboot.c
relay.c kernel/relay.c: change return type to vm_fault_t 2018-06-15 07:55:24 +09:00
resource.c libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
rseq.c rseq: Introduce restartable sequences system call 2018-06-06 11:58:31 +02:00
seccomp.c audit/stable-4.18 PR 20180605 2018-06-06 16:34:00 -07:00
signal.c signal: Remove no longer required irqsave/restore 2018-06-10 06:14:01 +02:00
smp.c
smpboot.c
smpboot.h
softirq.c Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 19:59:22 -07:00
stacktrace.c
stop_machine.c Linux 4.17-rc5 2018-05-15 08:10:50 +02:00
sys_ni.c Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 10:17:09 -07:00
sys.c mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct 2018-06-07 17:34:34 -07:00
sysctl_binary.c staging: irda: remove remaining remants of irda code removal 2018-04-16 11:26:49 +02:00
sysctl.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
task_work.c locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-12-17 13:57:15 +01:00
taskstats.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
test_kprobes.c
torture.c rcu: Rename cond_resched_rcu_qs() to cond_resched_tasks_rcu_qs() 2018-05-15 10:27:29 -07:00
tracepoint.c tracepoints: Fix the descriptions of tracepoint_probe_register{_prio} 2018-05-28 12:49:51 -04:00
tsacct.c
ucount.c headers: untangle kmemleak.h from mm.h 2018-04-05 21:36:27 -07:00
uid16.c fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers 2018-04-02 20:15:59 +02:00
uid16.h kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c 2018-04-02 20:15:30 +02:00
umh.c umh: fix race condition 2018-06-07 16:56:28 -04:00
up.c
user_namespace.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
user-return-notifier.c
user.c efivarfs: Limit the rate for non-root to read files 2018-02-22 10:21:02 -08:00
utsname_sysctl.c
utsname.c uts: create "struct uts_namespace" from kmem_cache 2018-04-11 10:28:35 -07:00
watchdog_hld.c
watchdog.c
workqueue_internal.h workqueue: Set worker->desc to workqueue name by default 2018-05-18 08:47:13 -07:00
workqueue.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00