linux_dsm_epyc7002/kernel
Kan Liang 556cccad38 perf/core: Pull pmu::sched_task() into perf_event_context_sched_in()
The pmu::sched_task() is a context switch callback. It passes the
cpuctx->task_ctx as a parameter to the lower code. To find the
cpuctx->task_ctx, the current code iterates a cpuctx list.

The same context was just iterated in perf_event_context_sched_in(),
which is invoked right before the pmu::sched_task().

Reuse the cpuctx->task_ctx from perf_event_context_sched_in() can avoid
the unnecessary iteration of the cpuctx list.

Both pmu::sched_task and perf_event_context_sched_in() have to disable
PMU. Pull the pmu::sched_task into perf_event_context_sched_in() can
also save the overhead from the PMU disable and reenable.

The new and old tasks may have equivalent contexts. The current code
optimize this case by swapping the context, which avoids the scheduling.
For this case, pmu::sched_task() is still required, e.g., restore the
LBR content.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200821195754.20159-1-kan.liang@linux.intel.com
2020-09-10 11:19:34 +02:00
..
bpf bpf: Delete repeated words in comments 2020-08-07 18:57:24 +02:00
cgroup
configs
debug
dma Cleanup, SECCOMP_FILTER support, message printing fixes, and other 2020-08-15 18:50:32 -07:00
entry
events perf/core: Pull pmu::sched_task() into perf_event_context_sched_in() 2020-09-10 11:19:34 +02:00
gcov
irq genirq: Unlock irq descriptor after errors 2020-08-13 09:35:59 +02:00
kcsan
livepatch
locking A set of locking fixes and updates: 2020-08-10 19:07:44 -07:00
power libnvdimm for 5.9 2020-08-11 10:59:19 -07:00
printk
rcu rcu: kasan: record and print call_rcu() call stack 2020-08-07 11:33:28 -07:00
sched Two fixes: fix a new tracepoint's output value, and fix the formatting of show-state syslog printouts. 2020-08-15 10:36:40 -07:00
time A set oftimekeeping/VDSO updates: 2020-08-14 14:26:08 -07:00
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-13 20:03:11 -07:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c \n 2020-08-06 19:29:51 -07:00
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c
crash_core.c kdump: append kernel build-id string to VMCOREINFO 2020-08-12 10:58:01 -07:00
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c kernel: add a kernel_wait helper 2020-08-12 10:57:59 -07:00
extable.c
fail_function.c
fork.c A set of locking fixes and updates: 2020-08-10 19:07:44 -07:00
freezer.c
futex.c futex: Convert to use the preferred 'fallthrough' macro 2020-08-13 21:02:12 +02:00
gen_kheaders.sh
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: make some symbols static 2020-08-12 10:58:02 -07:00
kexec_core.c
kexec_elf.c
kexec_file.c Misc fixes and small updates all around the place: 2020-08-15 10:38:03 -07:00
kexec_internal.h
kexec.c
kheaders.c
kmod.c kmod: remove redundant "be an" in the comment 2020-08-12 10:58:01 -07:00
kprobes.c Tracing updates for 5.9 2020-08-07 18:29:15 -07:00
ksysfs.c
kthread.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
latencytop.c
Makefile all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
module_signature.c
module_signing.c
module-internal.h
module.c Modules updates for v5.9 2020-08-14 11:07:02 -07:00
notifier.c
nsproxy.c
padata.c
panic.c panic: make print_oops_end_marker() static 2020-08-12 10:58:02 -07:00
params.c
pid_namespace.c
pid.c
profile.c
ptrace.c
range.c
reboot.c
regset.c
relay.c
resource.c
rseq.c
scs.c mm: memcontrol: account kernel stack per node 2020-08-07 11:33:25 -07:00
seccomp.c
signal.c task_work: only grab task signal lock when needed 2020-08-13 09:01:38 -06:00
smp.c
smpboot.c
smpboot.h
softirq.c
stackleak.c
stacktrace.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
stop_machine.c
sys_ni.c all arch: remove system call sys_sysctl 2020-08-14 19:56:56 -07:00
sys.c
sysctl-test.c
sysctl.c mm: use unsigned types for fragmentation score 2020-08-12 10:57:56 -07:00
task_work.c task_work: only grab task signal lock when needed 2020-08-13 09:01:38 -06:00
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c kernel: add a kernel_wait helper 2020-08-12 10:57:59 -07:00
up.c
user_namespace.c
user-return-notifier.c
user.c
usermode_driver.c
utsname_sysctl.c
utsname.c
watch_queue.c
watchdog_hld.c
watchdog.c
workqueue_internal.h
workqueue.c