Peter Zijlstra 3ca0ff571b locking/mutex: Rework mutex::owner ... The current mutex implementation has an atomic lock word and a non-atomic owner field. This disparity leads to a number of issues with the current mutex code as it means that we can have a locked mutex without an explicit owner (because the owner field has not been set, or already cleared). This leads to a number of weird corner cases, esp. between the optimistic spinning and debug code. Where the optimistic spinning code needs the owner field updated inside the lock region, the debug code is more relaxed because the whole lock is serialized by the wait_lock. Also, the spinning code itself has a few corner cases where we need to deal with a held lock without an owner field. Furthermore, it becomes even more of a problem when trying to fix starvation cases in the current code. We end up stacking special case on special case. To solve this rework the basic mutex implementation to be a single atomic word that contains the owner and uses the low bits for extra state. This matches how PI futexes and rt_mutex already work. By having the owner an integral part of the lock state a lot of the problems dissapear and we get a better option to deal with starvation cases, direct owner handoff. Changing the basic mutex does however invalidate all the arch specific mutex code; this patch leaves that unused in-place, a later patch will remove that. Tested-by: Jason Low <jason.low2@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>		2016-10-25 11:31:50 +02:00
..
bpf	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
configs	config: android: enable CONFIG_SECCOMP	2016-10-11 15:06:32 -07:00
debug	mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings	2016-02-22 08:51:37 +01:00
events	mm: replace get_user_pages_remote() write/force parameters with gup_flags	2016-10-19 08:12:02 -07:00
gcov	gcov: add support for gcc version >= 6	2016-07-15 14:54:27 +09:00
irq	kernel/irq: Export irq_set_parent()	2016-10-21 10:21:38 +02:00
livepatch	livepatch/module: make TAINT_LIVEPATCH module-specific	2016-08-26 14:42:08 +02:00
locking	locking/mutex: Rework mutex::owner	2016-10-25 11:31:50 +02:00
power	oom, suspend: fix oom_killer_disable vs. pm suspend properly	2016-10-07 18:46:27 -07:00
printk	printk: suppress empty continuation lines	2016-10-19 09:11:24 -07:00
rcu	This adds a new gcc plugin named "latent_entropy". It is designed to	2016-10-15 10:03:15 -07:00
sched	locking/mutex: Rework mutex::owner	2016-10-25 11:31:50 +02:00
time	alarmtimer: Remove unused but set variable	2016-10-17 11:59:37 +02:00
trace	Disable the __builtin_return_address() warning globally after all	2016-10-12 10:23:41 -07:00
.gitignore
acct.c
async.c	async: export current_is_async()	2015-11-19 17:51:48 +01:00
audit_fsnotify.c	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
audit_tree.c	audit: cleanup prune_tree_thread	2016-04-04 09:46:47 -04:00
audit_watch.c	Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit	2016-09-01 15:55:56 -07:00
audit.c	Merge branch 'stable-4.9' of git://git.infradead.org/users/pcmoore/audit	2016-10-04 14:21:41 -07:00
audit.h	Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit	2016-07-29 17:54:17 -07:00
auditfilter.c	audit: add fields to exclude filter by reusing user filter	2016-06-27 11:01:00 -04:00
auditsc.c	Merge branch 'stable-4.9' of git://git.infradead.org/users/pcmoore/audit	2016-10-04 14:21:41 -07:00
backtracetest.c
bounds.c
capability.c	kernel: Add noaudit variant of ns_capable()	2016-06-06 20:16:18 +10:00
cgroup_freezer.c	cgroup: kill cgrp_ss_priv[CGROUP_CANFORK_COUNT] and friends	2015-12-03 10:24:08 -05:00
cgroup_pids.c	cgroup: Use lld instead of ld when printing pids controller events_limit	2016-06-21 15:03:36 -04:00
cgroup.c	Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2016-10-14 12:18:50 -07:00
compat.c
configs.c
context_tracking.c	context_tracking: Switch to new static_branch API	2015-11-24 09:56:43 +01:00
cpu_pm.c
cpu.c	cpu/hotplug: Use distinct name for cpu_hotplug.dep_map	2016-10-16 11:09:32 +02:00
cpuset.c	Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2016-10-14 12:18:50 -07:00
crash_dump.c
cred.c	cred: Reject inodes with invalid ids in set_create_file_as()	2016-06-30 18:05:09 -05:00
delayacct.c	kmemcg: account certain kmem allocations to memcg	2016-01-14 16:00:49 -08:00
dma.c
elfcore.c
exec_domain.c
exit.c	mm, oom: enforce exit_oom_victim on current task	2016-10-07 18:46:28 -07:00
extable.c
fork.c	This adds a new gcc plugin named "latent_entropy". It is designed to	2016-10-15 10:03:15 -07:00
freezer.c	freezer, oom: check TIF_MEMDIE on the correct task	2016-07-28 16:07:41 -07:00
futex_compat.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-01-20 17:09:18 -08:00
futex.c	futex: Add some more function commentry	2016-09-05 17:20:18 +02:00
groups.c	cred: simpler, 1D supplementary groups	2016-10-07 18:46:30 -07:00
hung_task.c	hung_task: allow hung_task_panic when hung_task_warnings is 0	2016-10-11 15:06:33 -07:00
irq_work.c	treewide: Remove old email address	2015-11-23 09:44:58 +01:00
jump_label.c	powerpc updates for 4.8 #2	2016-08-05 09:00:54 -04:00
kallsyms.c	kallsyms: add support for relative offsets in kallsyms address table	2016-03-15 16:55:16 -07:00
kcmp.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-01-20 17:09:18 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kernel/kcov: unproxify debugfs file's fops	2016-06-15 04:56:35 -07:00
kexec_core.c	kexec: add restriction on kexec_load() segment sizes	2016-08-02 19:35:31 -04:00
kexec_file.c	kexec: fix double-free when failing to relocate the purgatory	2016-09-01 17:52:01 -07:00
kexec_internal.h	kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE	2016-01-20 17:09:18 -08:00
kexec.c	kexec: allow architectures to override boot mapping	2016-08-02 19:35:27 -04:00
kmod.c
kprobes.c	kprobes: include <asm/sections.h> instead of <asm-generic/sections.h>	2016-10-11 15:06:31 -07:00
ksysfs.c	kexec: add a kexec_crash_loaded() function	2016-08-02 19:35:30 -04:00
kthread.c	kthread: better support freezable kthread workers	2016-10-11 15:06:33 -07:00
latencytop.c	sched/debug: Make schedstats a runtime tunable that is disabled by default	2016-02-09 11:54:23 +01:00
Makefile	userns: Add per user namespace sysctls.	2016-08-08 13:18:58 -05:00
membarrier.c
memremap.c	mm: fix cache mode of dax pmd mappings	2016-09-09 17:34:46 -07:00
module_signing.c	KEYS: Move the point of trust determination to __key_link()	2016-04-11 22:43:43 +01:00
module-internal.h
module.c	livepatch/module: make TAINT_LIVEPATCH module-specific	2016-08-26 14:42:08 +02:00
notifier.c
nsproxy.c	cgroup: introduce cgroup namespaces	2016-02-16 13:04:58 -05:00
padata.c	padata: Convert to hotplug state machine	2016-09-19 21:44:30 +02:00
panic.c	x86/panic: replace smp_send_stop() with kdump friendly version in panic path	2016-10-11 15:06:32 -07:00
params.c
pid_namespace.c	Merge branch 'nsfs-ioctls' into HEAD	2016-09-22 20:00:36 -05:00
pid.c	remove lots of IS_ERR_VALUE abuses	2016-05-27 15:26:11 -07:00
profile.c	profile: Convert to hotplug state machine	2016-07-15 10:41:42 +02:00
ptrace.c	mm: replace access_process_vm() write parameter with gup_flags	2016-10-19 08:31:25 -07:00
range.c
reboot.c
relay.c	relay: Use irq_work instead of plain timer for deferred wakeup	2016-10-11 15:06:32 -07:00
resource.c	/proc/iomem: only expose physical resource addresses to privileged users	2016-04-14 12:56:09 -07:00
seccomp.c	seccomp: Fix tracer exit notifications during fatal signals	2016-08-30 16:12:46 -07:00
signal.c	x86/signal: Add SA_{X32,IA32}_ABI sa_flags	2016-09-14 21:28:11 +02:00
smp.c	smp: Allocate smp_call_on_cpu() workqueue on stack too	2016-09-22 14:49:10 +02:00
smpboot.c	kthread/smpboot: do not park in kthread_create_on_cpu()	2016-10-11 15:06:33 -07:00
smpboot.h	cpu/hotplug: Create hotplug threads	2016-03-01 20:36:56 +01:00
softirq.c	This adds a new gcc plugin named "latent_entropy". It is designed to	2016-10-15 10:03:15 -07:00
stacktrace.c
stop_machine.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-10-03 13:39:00 -07:00
sys_ni.c	x86/pkeys: Fix pkeys build breakage for some non-x86 arches	2016-09-13 14:41:36 +02:00
sys.c	prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable	2016-05-23 17:04:14 -07:00
sysctl_binary.c	kernel/sysctl_binary.c: use generic UUID library	2016-05-20 17:58:30 -07:00
sysctl.c	Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 13:04:49 -07:00
task_work.c	task_work: use READ_ONCE/lockless_dereference, avoid pi_lock if !task_works	2016-08-02 19:35:02 -04:00
taskstats.c	taskstats: use the libnl API to align nlattr on 64-bit	2016-04-23 20:13:25 -04:00
test_kprobes.c
torture.c	torture: Convert torture_shutdown() to hrtimer	2016-08-22 10:01:49 -07:00
tracepoint.c	kernel/...: convert pr_warning to pr_warn	2016-03-22 15:36:02 -07:00
tsacct.c	time, acct: Drop irq save & restore from __acct_update_integrals()	2016-02-29 09:53:09 +01:00
ucount.c	mntns: Add a limit on the number of mount namespaces.	2016-08-31 07:28:35 -05:00
uid16.c	cred: simpler, 1D supplementary groups	2016-10-07 18:46:30 -07:00
up.c	smp: Add function to execute a function synchronously on a CPU	2016-09-05 13:52:39 +02:00
user_namespace.c	Merge branch 'nsfs-ioctls' into HEAD	2016-09-22 20:00:36 -05:00
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c	Merge branch 'nsfs-ioctls' into HEAD	2016-09-22 20:00:36 -05:00
watchdog.c	Revert "perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86"	2016-07-10 20:58:36 +02:00
workqueue_internal.h	sched/core: Get rid of 'cpu' argument in wq_worker_sleeping()	2016-03-02 10:28:47 -05:00
workqueue.c	kthread: rename probe_kthread_data() to kthread_probe_data()	2016-10-11 15:06:33 -07:00