Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Wanpeng Li 89340d0935 Revert "locking/pvqspinlock: Don't wait if vCPU is preempted" ... This patch reverts commit 75437bb304 (locking/pvqspinlock: Don't wait if vCPU is preempted). A large performance regression was caused by this commit. on over-subscription scenarios. The test was run on a Xeon Skylake box, 2 sockets, 40 cores, 80 threads, with three VMs of 80 vCPUs each. The score of ebizzy -M is reduced from 13000-14000 records/s to 1700-1800 records/s: Host Guest score vanilla w/o kvm optimizations upstream 1700-1800 records/s vanilla w/o kvm optimizations revert 13000-14000 records/s vanilla w/ kvm optimizations upstream 4500-5000 records/s vanilla w/ kvm optimizations revert 14000-15500 records/s Exit from aggressive wait-early mechanism can result in premature yield and extra scheduling latency. Actually, only 6% of wait_early events are caused by vcpu_is_preempted() being true. However, when one vCPU voluntarily releases its vCPU, all the subsequently waiters in the queue will do the same and the cascading effect leads to bad performance. kvm optimizations: [1] commit d73eb57b80 (KVM: Boost vCPUs that are delivering interrupts) [2] commit 266e85a5ec (KVM: X86: Boost queue head vCPU to mitigate lock waiter preemption) Tested-by: loobinliu@tencent.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: loobinliu@tencent.com Cc: stable@vger.kernel.org Fixes: 75437bb304 (locking/pvqspinlock: Don't wait if vCPU is preempted) Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2019-09-25 10:22:37 +02:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next	2019-09-16 16:02:03 +02:00
cgroup	Merge branch 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2019-09-17 15:57:22 -07:00
configs
debug	kgdb: fix comment regarding static function	2019-09-03 11:19:41 +01:00
dma	powerpc updates for 5.4	2019-09-20 11:48:06 -07:00
events	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-09-17 12:35:15 -07:00
gcov	um: Enable CONFIG_CONSTRUCTORS	2019-09-15 21:37:13 +02:00
irq	Power management updates for 5.4-rc1	2019-09-17 19:15:14 -07:00
livepatch	livepatch: Nullify obj->mod in klp_module_coming()'s error path	2019-08-19 13:03:37 +02:00
locking	Revert "locking/pvqspinlock: Don't wait if vCPU is preempted"	2019-09-25 10:22:37 +02:00
power	Merge branches 'pm-opp', 'pm-qos', 'acpi-pm', 'pm-domains' and 'pm-tools'	2019-09-17 09:49:19 +02:00
printk	Merge branch 'for-5.4' into for-linus	2019-09-16 12:54:25 +02:00
rcu	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-09-16 17:25:49 -07:00
sched	hmm related patches for 5.4	2019-09-21 10:07:42 -07:00
time	Power management updates for 5.4-rc1	2019-09-17 19:15:14 -07:00
trace	powerpc updates for 5.4	2019-09-20 11:48:06 -07:00
.gitignore
acct.c
async.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441	2019-06-05 17:37:17 +02:00
audit.c	audit/stable-5.3 PR 20190702	2019-07-08 18:55:42 -07:00
audit.h	audit/stable-5.3 PR 20190702	2019-07-08 18:55:42 -07:00
audit_fsnotify.c
audit_tree.c
audit_watch.c
auditfilter.c	audit/stable-5.3 PR 20190702	2019-07-08 18:55:42 -07:00
auditsc.c
backtracetest.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441	2019-06-05 17:37:17 +02:00
bounds.c
capability.c
compat.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
configs.c	kernel/configs: Replace GPL boilerplate code with SPDX identifier	2019-07-30 18:34:15 +02:00
context_tracking.c
cpu.c	cpu/SMT: create and export cpu_smt_possible()	2019-09-24 13:37:28 +02:00
cpu_pm.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282	2019-06-05 17:36:37 +02:00
crash_core.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230	2019-06-19 17:09:06 +02:00
crash_dump.c
cred.c	Merge branch 'access-creds'	2019-07-25 08:36:29 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c	core-process-v5.4	2019-09-16 09:28:19 -07:00
extable.c	extable: Add function to search only kernel exception table	2019-08-21 22:23:48 +10:00
fail_function.c	fail_function: no need to check return value of debugfs_create functions	2019-06-03 15:49:06 +02:00
fork.c	hmm related patches for 5.4	2019-09-21 10:07:42 -07:00
freezer.c
futex.c	hrtimer/treewide: Use hrtimer_sleeper_start_expires()	2019-08-01 17:43:16 +02:00
gen_kheaders.sh	kheaders: include only headers into kheaders_data.tar.xz	2019-07-09 10:10:52 +09:00
groups.c
hung_task.c
iomem.c	mm/nvdimm: add is_ioremap_addr and use that to check ioremap address	2019-07-12 11:05:40 -07:00
irq_work.c
jump_label.c	jump_label: Don't warn on __exit jump entries	2019-08-29 15:10:10 +01:00
kallsyms.c	kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol	2019-08-27 16:19:56 +01:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt	sched/rt, Kconfig: Unbreak def/oldconfig with CONFIG_PREEMPT=y	2019-07-22 18:05:11 +02:00
kcov.c
kexec.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230	2019-06-19 17:09:06 +02:00
kexec_core.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230	2019-06-19 17:09:06 +02:00
kexec_elf.c	kexec_elf: support 32 bit ELF files	2019-09-06 23:58:44 +02:00
kexec_file.c	Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity	2019-07-08 20:28:59 -07:00
kexec_internal.h
kheaders.c
kmod.c
kprobes.c	Tracing updates:	2019-09-20 11:19:48 -07:00
ksysfs.c
kthread.c
latencytop.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441	2019-06-05 17:37:17 +02:00
Makefile	Kbuild updates for v5.4	2019-09-20 08:36:47 -07:00
module-internal.h
module.c	module: remove unneeded casts in cmp_name()	2019-09-11 21:41:56 +02:00
module_signing.c
notifier.c
nsproxy.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441	2019-06-05 17:37:17 +02:00
padata.c	padata: remove cpu_index from the parallel_queue	2019-09-13 21:15:41 +10:00
panic.c	docs: admin-guide: move sysctl directory to it	2019-07-15 11:03:01 -03:00
params.c
pid.c	kernel/pid.c: convert struct pid count to refcount_t	2019-07-16 19:23:24 -07:00
pid_namespace.c	proc/sysctl: add shared variables for range check	2019-07-18 17:08:07 -07:00
profile.c
ptrace.c	ptrace: add PTRACE_GET_SYSCALL_INFO request	2019-07-16 19:23:24 -07:00
range.c
reboot.c
relay.c
resource.c	resource: add a not device managed request_free_mem_region variant	2019-08-20 09:39:41 -03:00
rseq.c
seccomp.c
signal.c	core-process-v5.4	2019-09-16 09:28:19 -07:00
smp.c	smp: Warn on function calls from softirq context	2019-07-20 11:27:16 +02:00
smpboot.c
smpboot.h
softirq.c	Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-07-08 11:01:13 -07:00
stackleak.c
stacktrace.c	stacktrace: Constify 'entries' arguments	2019-07-25 15:43:26 +02:00
stop_machine.c	stop_machine: Fix stop_cpus_in_progress ordering	2019-08-08 09:09:30 +02:00
sys.c	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2019-09-17 12:35:15 -07:00
sys_ni.c	arch: handle arches who do not yet define clone3	2019-06-21 01:54:53 +02:00
sysctl.c	proc/sysctl: add shared variables for range check	2019-07-18 17:08:07 -07:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
torture.c	torture: Remove exporting of internal functions	2019-08-01 14:30:22 -07:00
tracepoint.c	The main changes in this release include:	2019-07-18 11:51:00 -07:00
tsacct.c
ucount.c	proc/sysctl: add shared variables for range check	2019-07-18 17:08:07 -07:00
uid16.c
uid16.h
umh.c
up.c	smp: Remove smp_call_function() and on_each_cpu() return values	2019-06-23 14:26:26 +02:00
user-return-notifier.c
user.c	Keyrings namespacing	2019-07-08 19:36:47 -07:00
user_namespace.c	Keyrings namespacing	2019-07-08 19:36:47 -07:00
utsname.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441	2019-06-05 17:37:17 +02:00
utsname_sysctl.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441	2019-06-05 17:37:17 +02:00
watchdog.c	watchdog: Mark watchdog_hrtimer to expire in hard interrupt context	2019-08-01 20:51:20 +02:00
watchdog_hld.c
workqueue.c	workqueue: require CPU hotplug read exclusion for apply_workqueue_attrs	2019-09-13 21:15:40 +10:00
workqueue_internal.h