Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Mel Gorman 65d8fc777f futex: Remove requirement for lock_page() in get_futex_key() ... When dealing with key handling for shared futexes, we can drastically reduce the usage/need of the page lock. 1) For anonymous pages, the associated futex object is the mm_struct which does not require the page lock. 2) For inode based, keys, we can check under RCU read lock if the page mapping is still valid and take reference to the inode. This just leaves one rare race that requires the page lock in the slow path when examining the swapcache. Additionally realtime users currently have a problem with the page lock being contended for unbounded periods of time during futex operations. Task A get_futex_key() lock_page() ---> preempted Now any other task trying to lock that page will have to wait until task A gets scheduled back in, which is an unbound time. With this patch, we pretty much have a lockless futex_get_key(). Experiments show that this patch can boost/speedup the hashing of shared futexes with the perf futex benchmarks (which is good for measuring such change) by up to 45% when there are high (> 100) thread counts on a 60 core Westmere. Lower counts are pretty much in the noise range or less than 10%, but mid range can be seen at over 30% overall throughput (hash ops/sec). This makes anon-mem shared futexes much closer to its private counterpart. Signed-off-by: Mel Gorman <mgorman@suse.de> [ Ported on top of thp refcount rework, changelog, comments, fixes. ] Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Mason <clm@fb.com> Cc: Darren Hart <dvhart@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: dave@stgolabs.net Link: http://lkml.kernel.org/r/1455045314-8305-3-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>		2016-02-17 10:42:17 +01:00
..
bpf	bpf: fix branch offset adjustment on backjumps after patching ctx expansion	2016-02-10 16:56:47 -05:00
configs
debug	module: use a structure to encapsulate layout.	2015-12-04 22:46:25 +01:00
events	Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-01-31 15:38:27 -08:00
gcov	gcov: use within_module() helper.	2015-12-04 22:46:25 +01:00
irq	Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-01-31 14:48:58 -08:00
livepatch	livepatch: Cleanup module page permission changes	2015-12-04 22:51:07 +01:00
locking	kernel/locking/lockdep.c: convert hash tables to hlists	2016-02-11 18:35:48 -08:00
power	PM: APM_EMULATION does not depend on PM	2016-01-27 23:20:14 +01:00
printk	kernel: printk: specify alignment for struct printk_log	2016-01-20 17:09:18 -08:00
rcu	Merge branches 'doc.2015.12.05a', 'exp.2015.12.07a', 'fixes.2015.12.07a', 'list.2015.12.04b' and 'torture.2015.12.05a' into HEAD	2015-12-07 17:02:54 -08:00
sched	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-01-31 15:44:04 -08:00
time	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-01-31 15:49:06 -08:00
trace	A cleanup to the stack tracer broke stack tracing on s390.	2016-02-03 09:31:34 -08:00
.gitignore	certs: add .gitignore to stop git nagging about x509_certificate_list	2015-10-21 15:18:35 +01:00
acct.c
async.c	async: export current_is_async()	2015-11-19 17:51:48 +01:00
audit.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2016-01-17 19:13:15 -08:00
audit.h	security: Make inode argument of inode_getsecid non-const	2015-12-24 11:09:39 -05:00
audit_fsnotify.c	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
audit_tree.c	audit: audit_tree_match can be boolean	2015-11-04 08:23:51 -05:00
audit_watch.c	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
auditfilter.c	audit: fix comment block whitespace	2015-11-04 08:23:51 -05:00
auditsc.c	security: Make inode argument of inode_getsecid non-const	2015-12-24 11:09:39 -05:00
backtracetest.c
bounds.c
capability.c
cgroup.c	cgroup: make sure a parent css isn't freed before its children	2016-01-22 10:42:58 -05:00
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_pids: fix a typo.	2015-12-14 14:54:37 -05:00
compat.c
configs.c
context_tracking.c	context_tracking: Switch to new static_branch API	2015-11-24 09:56:43 +01:00
cpu.c	kernel/cpu.c: make set_cpu_* static inlines	2016-01-20 17:09:18 -08:00
cpu_pm.c	kernel/cpu_pm: fix cpu_cluster_pm_exit comment	2015-09-03 02:42:20 +02:00
cpuset.c	cpuset: make mm migration asynchronous	2016-01-22 10:22:46 -05:00
crash_dump.c
cred.c	kmemcg: account certain kmem allocations to memcg	2016-01-14 16:00:49 -08:00
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	exit: remove unneeded declaration of exit_mm()	2016-01-20 17:09:18 -08:00
extable.c	kernel/extable.c: remove duplicated include	2015-09-10 13:29:01 -07:00
fork.c	mm: rework virtual memory accounting	2016-01-14 16:00:49 -08:00
freezer.c
futex.c	futex: Remove requirement for lock_page() in get_futex_key()	2016-02-17 10:42:17 +01:00
futex_compat.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-01-20 17:09:18 -08:00
groups.c
hung_task.c
irq_work.c	treewide: Remove old email address	2015-11-23 09:44:58 +01:00
jump_label.c	treewide: Remove old email address	2015-11-23 09:44:58 +01:00
kallsyms.c
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
kexec.c	kexec: set KEXEC_TYPE_CRASH before sanity_check_segment_list()	2016-01-20 17:09:18 -08:00
kexec_core.c	kernel/kexec_core.c: use list_for_each_entry_safe in kimage_free_page_list	2016-01-20 17:09:18 -08:00
kexec_file.c	kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE	2016-01-20 17:09:18 -08:00
kexec_internal.h	kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE	2016-01-20 17:09:18 -08:00
kmod.c	kmod: don't run async usermode helper as a child of kworker thread	2015-10-23 17:55:10 +09:00
kprobes.c
ksysfs.c	rcu: Remove TINY_RCU bloat from pointless boot parameters	2015-12-07 16:59:37 -08:00
kthread.c	kernel/kthread.c:kthread_create_on_node(): clarify documentation	2015-09-04 16:54:41 -07:00
latencytop.c
Makefile	sys_membarrier(): system-wide memory barrier (generic, x86)	2015-09-11 15:21:34 -07:00
membarrier.c	sys_membarrier(): system-wide memory barrier (generic, x86)	2015-09-11 15:21:34 -07:00
memremap.c	mm: fix pfn_t vs highmem	2016-02-11 18:35:48 -08:00
module-internal.h
module.c	modules: fix longstanding /proc/kallsyms vs module insertion race.	2016-02-03 16:58:15 +10:30
module_signing.c	KEYS: Merge the type-specific data with the payload data	2015-10-21 15:18:36 +01:00
notifier.c	Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-09-01 08:40:25 -07:00
nsproxy.c
padata.c
panic.c	printk: do cond_resched() between lines while outputting to consoles	2016-01-16 11:17:25 -08:00
params.c	Nothing exciting, minor tweaks and cleanups.	2015-11-09 15:53:39 -08:00
pid.c	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-01-31 15:44:04 -08:00
pid_namespace.c
profile.c	mm: rename alloc_pages_exact_node() to __alloc_pages_node()	2015-09-08 15:35:28 -07:00
ptrace.c	ptrace: use fsuid, fsgid, effective creds for fs access checks	2016-01-20 17:09:18 -08:00
range.c
reboot.c	kexec: split kexec_load syscall from kexec core code	2015-09-10 13:29:01 -07:00
relay.c	wrappers for ->i_mutex access	2016-01-22 18:04:28 -05:00
resource.c	restrict /dev/mem to idle io memory ranges	2016-01-09 06:30:49 -08:00
seccomp.c	seccomp: always propagate NO_NEW_PRIVS on tsync	2016-01-27 07:38:25 -08:00
signal.c	signals: avoid random wakeups in sigsuspend()	2016-02-05 18:10:40 -08:00
smp.c	mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd	2015-11-06 17:50:42 -08:00
smpboot.c	stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()	2015-10-20 10:23:55 +02:00
smpboot.h
softirq.c
stacktrace.c
stop_machine.c	kernel/stop_machine.c: remove CONFIG_SMP dependencies	2016-01-16 11:17:24 -08:00
sys.c	prctl: take mmap sem for writing to protect against others	2016-01-20 17:09:18 -08:00
sys_ni.c	vfs: add copy_file_range syscall and vfs helper	2015-12-01 14:00:53 -05:00
sysctl.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-01-22 10:24:03 -08:00
sysctl_binary.c
task_work.c	task_work: remove fifo ordering guarantee	2015-09-05 13:46:58 -07:00
taskstats.c
test_kprobes.c
torture.c	torture: Consolidate cond_resched_rcu_qs() into stutter_wait()	2015-10-06 11:25:01 -07:00
tracepoint.c	tracepoint: Give priority to probes of tracepoints	2015-10-25 21:33:54 -04:00
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c
user_namespace.c	kernel/*: switch to memdup_user_nul()	2016-01-04 10:27:55 -05:00
utsname.c
utsname_sysctl.c
watchdog.c	Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2016-01-11 18:53:13 -08:00
workqueue.c	workqueue: handle NUMA_NO_NODE for unbound pool_workqueue lookup	2016-02-10 12:13:05 -05:00
workqueue_internal.h