Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Peter Zijlstra (Intel) 69f9cae909 locking/qspinlock: Optimize for smaller NR_CPUS ... When we allow for a max NR_CPUS < 2^14 we can optimize the pending wait-acquire and the xchg_tail() operations. By growing the pending bit to a byte, we reduce the tail to 16bit. This means we can use xchg16 for the tail part and do away with all the repeated compxchg() operations. This in turn allows us to unconditionally acquire; the locked state as observed by the wait loops cannot change. And because both locked and pending are now a full byte we can use simple stores for the state transition, obviating one atomic operation entirely. This optimization is needed to make the qspinlock achieve performance parity with ticket spinlock at light load. All this is horribly broken on Alpha pre EV56 (and any other arch that cannot do single-copy atomic byte stores). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-6-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>		2015-05-08 12:36:48 +02:00
..
bpf	bpf: fix 64-bit divide	2015-04-27 23:11:49 -04:00
configs
debug	debug: prevent entering debug mode on panic/exception.	2015-02-19 12:39:03 -06:00
events	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2015-04-15 09:00:47 -07:00
gcov	gcov: fix softlockups	2015-04-17 09:04:08 -04:00
irq	irqchip core change for v4.1 (round 3)	2015-04-11 11:17:28 +02:00
livepatch	Merge branch 'for-4.1/core-noarch' into for-linus	2015-04-13 23:57:20 +02:00
locking	locking/qspinlock: Optimize for smaller NR_CPUS	2015-05-08 12:36:48 +02:00
power	Merge back earlier suspend/hibernate material for v4.1.	2015-04-10 12:01:59 +02:00
printk	TTY/Serial patches for 4.1-rc1	2015-04-21 09:33:10 -07:00
rcu	rcu: Control grace-period delays directly from value	2015-04-14 19:33:59 -07:00
sched	Power management and ACPI fixes for v4.1-rc2	2015-04-30 14:23:31 -07:00
time	Char/Misc driver patches for 4.1-rc1	2015-04-21 09:42:58 -07:00
trace	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-04-26 17:22:07 -07:00
.gitignore
acct.c	acct: check FMODE_CAN_WRITE	2015-04-11 22:27:55 -04:00
async.c
audit.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-04-26 17:22:07 -07:00
audit.h	Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit	2015-04-22 14:49:23 -07:00
audit_tree.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-04-26 17:22:07 -07:00
audit_watch.c	VFS: audit: d_backing_inode() annotations	2015-04-15 15:06:55 -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 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-04-26 17:22:07 -07:00
backtracetest.c
bounds.c
capability.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
cgroup.c	cgroup: remove use of seq_printf return value	2015-04-15 16:35:25 -07:00
cgroup_freezer.c
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	context_tracking: Export context_tracking_user_enter/exit	2015-03-09 15:43:00 +01:00
cpu.c	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-14 13:36:04 -07:00
cpu_pm.c
cpuset.c	kernel, cpuset: remove exception for __GFP_THISNODE	2015-04-14 16:49:03 -07:00
crash_dump.c
cred.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c	Remove rest of exec domains.	2015-04-12 21:03:31 +02:00
exit.c	Remove execution domain support	2015-04-12 20:58:24 +02:00
extable.c
fork.c	oprofile: reduce mmap_sem hold for mm->exe_file	2015-04-17 09:04:11 -04:00
freezer.c
futex.c	Linux 34.0-rc1	2015-02-24 08:41:07 +01:00
futex_compat.c
groups.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
hung_task.c	kernel/hung_task.c: change hung_task.c to use for_each_process_thread()	2015-04-15 16:35:22 -07:00
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks	locking/qspinlock: Introduce a simple generic 4-byte queued spinlock	2015-05-08 12:36:25 +02:00
Kconfig.preempt
kexec.c	kexec: allocate the kexec control page with KEXEC_CONTROL_MEMORY_GFP	2015-04-23 16:52:01 +02:00
kmod.c
kprobes.c	kprobes: makes kprobes/enabled works correctly for optimized kprobes.	2015-02-13 21:21:42 -08:00
ksysfs.c
kthread.c
latencytop.c
Makefile	modsign: change default key details	2015-04-30 09:35:41 -07:00
module-internal.h
module.c	Quentin opened a can of worms by adding extable entry checking to modpost,	2015-04-22 09:49:24 -07:00
module_signing.c
notifier.c
nsproxy.c
padata.c	padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
panic.c
params.c	params: handle quotes properly for values not of form foo="bar".	2015-04-15 13:31:23 +09:30
pid.c	fork: report pid reservation failure properly	2015-04-17 09:04:06 -04:00
pid_namespace.c
profile.c	profile: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
ptrace.c	ptrace: ptrace_detach() can no longer race with SIGKILL	2015-04-17 09:04:06 -04:00
range.c
reboot.c	kernel/reboot.c: add orderly_reboot for graceful reboot	2015-04-15 16:35:23 -07:00
relay.c	VFS: kernel/: d_inode() annotations	2015-04-15 15:06:55 -04:00
resource.c	kernel/resource.c: remove deprecated __check_region() and friends	2015-04-15 16:35:22 -07:00
seccomp.c	seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO	2015-02-17 14:34:55 -08:00
signal.c	signal: remove warning about using SI_TKILL in rt_[tg]sigqueueinfo	2015-04-17 09:04:06 -04:00
smp.c	smp: Fix error case handling in smp_call_function_*()	2015-04-19 13:19:23 -07:00
smpboot.c	smpboot: Add common code for notification from dying CPU	2015-03-11 13:20:25 -07:00
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
stop_machine.c
sys.c	prctl: avoid using mmap_sem for exe_file serialization	2015-04-17 09:04:07 -04:00
sys_ni.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
sysctl.c	kernel/sysctl.c: detect overflows when converting to int	2015-04-17 09:04:08 -04:00
sysctl_binary.c
system_certificates.S
system_keyring.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c
watchdog.c	Merge branch 'akpm' (patches from Andrew)	2015-04-14 16:49:17 -07:00
workqueue.c	workqueue: Reorder sysfs code	2015-04-06 11:16:04 -04:00
workqueue_internal.h