Jason Low 9198f6edfd locking/rwsem: Fix lock optimistic spinning when owner is not running ... Ming reported soft lockups occurring when running xfstest due to the following tip:locking/core commit: b3fd4f03ca ("locking/rwsem: Avoid deceiving lock spinners") When doing optimistic spinning in rwsem, threads should stop spinning when the lock owner is not running. While a thread is spinning on owner, if the owner reschedules, owner->on_cpu returns false and we stop spinning. However, this commit essentially caused the check to get ignored because when we break out of the spin loop due to !on_cpu, we continue spinning if sem->owner != NULL. This patch fixes this by making sure we stop spinning if the owner is not running. Furthermore, just like with mutexes, refactor the code such that we don't have separate checks for owner_running(). This makes it more straightforward in terms of why we exit the spin on owner loop and we would also avoid needing to "guess" why we broke out of the loop to make this more readable. Reported-and-tested-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jason Low <jason.low2@hp.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michel Lespinasse <walken@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/1425714331.2475.388.camel@j-VirtualBox Signed-off-by: Ingo Molnar <mingo@kernel.org>		2015-03-07 09:50:49 +01:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2015-01-27 13:55:36 -08:00
configs	x86: Add "make tinyconfig" to configure the tiniest possible kernel	2014-08-08 16:30:24 -07:00
debug	debug: prevent entering debug mode on panic/exception.	2015-02-19 12:39:03 -06:00
events	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-16 14:58:12 -08:00
gcov	kbuild,gcov: simplify kernel/gcov/Makefile more	2015-01-09 17:25:44 +01:00
irq	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-16 15:20:40 -08:00
livepatch	livepatch: add missing newline to error message	2015-02-06 21:28:35 +01:00
locking	locking/rwsem: Fix lock optimistic spinning when owner is not running	2015-03-07 09:50:49 +01:00
power	PM / sleep: Re-implement suspend-to-idle handling	2015-02-13 23:49:36 +01:00
printk	KGDB/KDB New:	2015-02-20 15:13:29 -08:00
rcu	Merge branches 'core-urgent-for-linus' and 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-21 10:36:06 -08:00
sched	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-21 10:40:02 -08:00
time	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-21 11:05:22 -08:00
trace	tracing: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:37 -08:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	locking/mcs: Better differentiate between MCS variants	2015-01-14 15:07:32 +01:00
Kconfig.preempt	…
Makefile	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2015-02-11 20:25:11 -08:00
acct.c	new fs_pin killing logics	2015-01-25 23:17:28 -05:00
async.c	kernel/async.c: switch to pr_foo()	2014-10-09 22:26:04 -04:00
audit.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2014-12-30 10:45:47 -08:00
audit.h	audit: replace getname()/putname() hacks with reference counters	2015-01-23 00:23:58 -05:00
audit_tree.c	fsnotify: unify inode and mount marks handling	2014-12-13 12:42:53 -08:00
audit_watch.c	audit: invalid op= values for rules	2014-09-23 16:37:53 -04:00
auditfilter.c	Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit	2015-02-11 20:07:47 -08:00
auditsc.c	Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-02-17 15:27:47 -08:00
backtracetest.c	kernel/backtracetest.c: replace no level printk by pr_info()	2014-06-04 16:54:14 -07:00
bounds.c	page-cgroup: get rid of NR_PCG_FLAGS	2014-08-08 15:57:18 -07:00
capability.c	CAPABILITIES: remove undefined caps from all processes	2014-07-24 21:53:47 +10:00
cgroup.c	kernfs: remove KERNFS_STATIC_NAME	2015-02-13 21:21:36 -08:00
cgroup_freezer.c	cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes	2014-07-15 11:05:09 -04:00
compat.c	all arches, signal: move restart_block to struct task_struct	2015-02-12 18:54:12 -08:00
configs.c	…
context_tracking.c	sched: stop the unbound recursion in preempt_schedule_context()	2014-10-28 10:46:05 +01:00
cpu.c	hotplugcpu: Avoid deadlocks by waking active_writer	2015-01-06 11:01:14 -08:00
cpu_pm.c	…
cpuset.c	cpuset: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:37 -08:00
crash_dump.c	crash_dump: Make is_kdump_kernel() accessible from modules	2014-08-25 15:42:19 -07:00
cred.c	…
delayacct.c	delayacct: Remove braindamaged type conversions	2014-07-23 10:18:06 -07:00
dma.c	…
elfcore.c	…
exec_domain.c	kernel/exec_domain.c: code clean-up	2014-06-04 16:54:15 -07:00
exit.c	oom, PM: make OOM detection in the freezer path raceless	2015-02-11 17:06:03 -08:00
extable.c	ftrace/x86/extable: Add is_ftrace_trampoline() function	2014-11-19 15:25:26 -05:00
fork.c	mm: do not use mm->nr_pmds on !MMU configurations	2015-02-12 18:54:10 -08:00
freezer.c	freezer: remove obsolete comments in __thaw_task()	2014-10-21 23:44:20 +02:00
futex.c	Linux 34.0-rc1	2015-02-24 08:41:07 +01:00
futex_compat.c	…
groups.c	userns: Don't allow setgroups until a gid mapping has been setablished	2014-12-09 16:58:40 -06:00
hung_task.c	kernel/hung_task.c: convert simple_strtoul to kstrtouint	2014-06-04 16:54:15 -07:00
irq_work.c	percpu: Convert remaining __get_cpu_var uses in 3.18-rcX	2014-10-29 11:18:18 -04:00
jump_label.c	…
kallsyms.c	kernel/kallsyms.c: use __seq_open_private()	2014-10-14 02:18:16 +02:00
kcmp.c	kcmp: fix standard comparison bug	2014-09-10 15:42:12 -07:00
kexec.c	kexec: simplify conditional	2015-02-17 14:34:51 -08:00
kmod.c	usermodehelper: kill the kmod_thread_locker logic	2014-12-10 17:41:17 -08:00
kprobes.c	kprobes: makes kprobes/enabled works correctly for optimized kprobes.	2015-02-13 21:21:42 -08:00
ksysfs.c	kobject: Make support for uevent_helper optional.	2014-04-25 12:00:49 -07:00
kthread.c	kernel/kthread.c: partial revert of 81c98869fa ("kthread: ensure locality of task_struct allocations")	2014-10-09 22:25:51 -04:00
latencytop.c	kernel/latencytop.c: convert seq_printf to seq_puts	2014-06-04 16:54:15 -07:00
module-internal.h	…
module.c	kernel/module.c: do not inline do_init_module()	2015-02-17 14:34:53 -08:00
module_signing.c	…
notifier.c	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
nsproxy.c	bury struct proc_ns in fs/proc	2014-12-04 14:34:54 -05:00
padata.c	padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
panic.c	livepatch: kernel: add TAINT_LIVEPATCH	2014-12-22 15:40:48 +01:00
params.c	param: fix uninitialized read with CONFIG_DEBUG_LOCK_ALLOC	2015-01-20 11:38:31 +10:30
pid.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-12-16 15:53:03 -08:00
pid_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-12-16 15:53:03 -08:00
profile.c	profile: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
ptrace.c	ptrace: remove linux/compat.h inclusion under CONFIG_COMPAT	2015-02-17 14:34:51 -08:00
range.c	kernel: avoid overflow in cmp_range	2015-01-17 10:02:23 +13:00
reboot.c	kernel: add support for kernel restart handler call chain	2014-09-26 00:00:06 -07:00
relay.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-04-12 14:49:50 -07:00
resource.c	resources: Move struct resource_list_entry from ACPI into resource core	2015-02-05 15:09:25 +01:00
seccomp.c	seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO	2015-02-17 14:34:55 -08:00
signal.c	signal: use current->state helpers	2015-02-17 14:34:51 -08:00
smp.c	Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2014-10-15 07:48:18 +02:00
smpboot.c	smpboot: Add missing get_online_cpus() in smpboot_register_percpu_thread()	2015-01-23 11:33:51 +01:00
smpboot.h	…
softirq.c	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-09 15:24:03 -08:00
stacktrace.c	stacktrace: introduce snprint_stack_trace for buffer output	2014-12-13 12:42:48 -08:00
stop_machine.c	kernel/stop_machine.c: kernel-doc warning fix	2014-06-04 16:54:15 -07:00
sys.c	Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus	2015-02-21 19:41:38 -08:00
sys_ni.c	syscalls: implement execveat() system call	2014-12-13 12:42:51 -08:00
sysctl.c	mm, hugetlb: remove unnecessary lower bound on sysctl handlers"?	2015-02-10 14:30:34 -08:00
sysctl_binary.c	kernel: add panic_on_warn	2014-12-10 17:41:10 -08:00
system_certificates.S	…
system_keyring.c	KEYS: validate certificate trust only with builtin keys	2014-07-17 09:35:17 -04:00
task_work.c	…
taskstats.c	netlink: make nlmsg_end() and genlmsg_end() void	2015-01-18 01:03:45 -05:00
test_kprobes.c	kernel/test_kprobes.c: use current logging functions	2014-08-08 15:57:18 -07:00
torture.c	torture: Address race in module cleanup	2014-09-16 13:41:06 -07:00
tracepoint.c	tracing: syscall_regfunc() should not skip kernel threads	2014-06-21 00:15:26 -04:00
tsacct.c	sched: Make task->start_time nanoseconds based	2014-07-23 10:18:05 -07:00
uid16.c	groups: Consolidate the setgroups permission checks	2014-12-05 17:19:27 -06:00
up.c	smp: Rename __smp_call_function_single() to smp_call_function_single_async()	2014-02-24 14:47:15 -08:00
user-return-notifier.c	scheduler: Replace __get_cpu_var with this_cpu_ptr	2014-08-26 13:45:45 -04:00
user.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2014-12-17 12:31:40 -08:00
user_namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2014-12-17 12:31:40 -08:00
utsname.c	copy address of proc_ns_ops into ns_common	2014-12-04 14:34:47 -05:00
utsname_sysctl.c	sysctl: convert use of typedef ctl_table to struct ctl_table	2014-06-06 16:08:16 -07:00
watchdog.c	kernel/sched/clock.c: add another clock for use with the soft lockup watchdog	2015-02-12 18:54:13 -08:00
workqueue.c	workqueue: use %*pb[l] to format bitmaps including cpumasks and nodemasks	2015-02-13 21:21:37 -08:00
workqueue_internal.h	workqueue: rename manager_mutex to attach_mutex	2014-05-20 10:59:32 -04:00