linux-uconsole/kernel
Chris Redpath 4cb65352a3 ANDROID: Add hold functionality to schedtune CPU boost
When tasks come and go from a runqueue quickly, this can lead to boost
being applied and removed quickly which sometimes means we cannot raise
the CPU frequency again when we need to (due to the rate limit on
frequency updates). This has proved to be a particular issue for RT tasks
and alternative methods have been used in the past to work around it.

This is an attempt to solve the issue for all task classes and cpufreq
governors by introducing a generic mechanism in schedtune to retain
the max boost level from task enqueue for a minimum period - defined
here as 50ms. This timeout was determined experimentally and is not
configurable.

A sched_feat guards the application of this to tasks - in the default
configuration, task boosting only applied to tasks which have RT
policy. Change SCHEDTUNE_BOOST_HOLD_ALL to true to apply it to all
tasks regardless of class.

It works like so:

Every task enqueue (in an allowed class) stores a cpu-local timestamp.
If the task is not a member of an allowed class (all or RT depending
upon feature selection), the timestamp is not updated.
The boost group will stay active regardless of tasks present until
50ms beyond the last timestamp stored. We also store the timestamp
of the active boost group to avoid unneccesarily revisiting the boost
groups when checking CPU boost level.

If the timestamp is more than 50ms in the past when we check boost then
we re-evaluate the boost groups for that CPU, taking into account the
timestamps associated with each group.

Idea based on rt-boost-retention patches from Joel.

Change-Id: I52cc2d2e82d1c5aa03550378c8836764f41630c1
Suggested-by: Joel Fernandes <joelaf@google.com>
Reviewed-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
[forward ported from android-4.9-eas-dev proposal]
(cherry picked from commit a485e8b7bf8e95759e600396feeb7bfb400b6e46)
[ - Trivial cherry-pick conflicts in include/trace/events/sched.h ]
Signed-off-by: Quentin Perret <quentin.perret@arm.com>
2018-10-26 12:44:06 +01:00
..
bpf xsk: do not call synchronize_net() under RCU read lock 2018-10-11 10:19:01 +02:00
cgroup cgroup: Fix dom_cgrp propagation when enabling threaded mode 2018-10-04 13:28:08 -07:00
configs kconfig: tinyconfig: remove stale stack protector fixups 2018-06-15 07:15:28 +09:00
debug treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
dma dma-mapping: add the missing ARCH_HAS_SYNC_DMA_FOR_CPU_ALL declaration 2018-09-25 15:11:58 -07:00
events perf/ring_buffer: Prevent concurent ring buffer access 2018-10-02 09:37:59 +02:00
gcov gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT 2018-06-08 18:56:02 +09:00
irq Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 10:47:26 -07:00
livepatch Merge branch 'for-4.19/upstream' into for-linus 2018-08-20 18:33:50 +02:00
locking locking/ww_mutex: Fix runtime warning in the WW mutex selftest 2018-10-03 08:56:31 +02:00
power FROMLIST: PM / EM: Expose the Energy Model in sysfs 2018-10-26 11:47:11 +01:00
printk Printk changes for 4.19-rc4 2018-09-13 19:37:08 -10:00
rcu Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 11:25:07 -07:00
sched ANDROID: Add hold functionality to schedtune CPU boost 2018-10-26 12:44:06 +01:00
time clocksource: Revert "Remove kthread" 2018-09-06 23:38:35 +02:00
trace tracing: Fix synthetic event to allow semicolon at end 2018-10-19 17:25:11 -04:00
.gitignore
acct.c kernel/acct.c: fix the acct->needcheck check in check_free_space() 2018-01-04 16:45:09 -08:00
async.c kernel/async.c: revert "async: simplify lowest_in_progress()" 2018-02-06 18:32:44 -08:00
audit.c audit: use ktime_get_coarse_real_ts64() for timestamps 2018-07-17 14:45:08 -04:00
audit.h audit: track the owner of the command mutex ourselves 2018-02-23 11:22:22 -05:00
audit_fsnotify.c fsnotify: add fsnotify_add_inode_mark() wrappers 2018-05-18 14:58:22 +02:00
audit_tree.c \n 2018-08-17 09:41:28 -07:00
audit_watch.c audit: fix use-after-free in audit_add_watch 2018-07-18 11:43:36 -04:00
auditfilter.c audit: rename FILTER_TYPE to FILTER_EXCLUDE 2018-06-19 10:39:54 -04:00
auditsc.c audit/stable-4.18 PR 20180814 2018-08-15 10:46:54 -07:00
backtracetest.c
bounds.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
capability.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat.c time: Enable get/put_compat_itimerspec64 always 2018-06-24 14:39:47 +02:00
configs.c
context_tracking.c
cpu.c cpu/hotplug: Prevent state corruption on error rollback 2018-09-06 15:21:38 +02:00
cpu_pm.c
crash_core.c kernel/crash_core.c: print timestamp using time64_t 2018-08-22 10:52:47 -07:00
crash_dump.c
cred.c
delayacct.c delayacct: Use raw_spinlocks 2018-04-27 14:34:51 +02:00
dma.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
elfcore.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
exec_domain.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
exit.c signal: Pass pid type into group_send_sig_info 2018-07-21 12:57:35 -05:00
extable.c extable: Make init_kernel_text() global 2018-02-21 16:54:06 +01:00
fail_function.c bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe 2018-06-21 12:33:19 +02:00
fork.c mm: respect arch_dup_mmap() return value 2018-09-04 16:45:02 -07:00
freezer.c PM / reboot: Eliminate race between reboot and suspend 2018-08-06 12:35:20 +02:00
futex.c futex: Mark expected switch fall-throughs 2018-08-20 18:23:00 +02:00
futex_compat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
groups.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
hung_task.c kernel/hung_task.c: allow to set checking interval separately from timeout 2018-08-22 10:52:47 -07:00
iomem.c memremap: split devm_memremap_pages() and memremap() infrastructure 2018-05-15 23:08:33 -07:00
irq_work.c irq/work: Improve the flag definitions 2018-01-08 19:43:15 +01:00
jump_label.c jump_label: Fix typo in warning message 2018-09-10 10:15:48 +02:00
kallsyms.c kallsyms, x86: Export addresses of PTI entry trampolines 2018-08-14 19:12:29 -03:00
kcmp.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt kconfig: include kernel/Kconfig.preempt from init/Kconfig 2018-08-02 08:06:54 +09:00
kcov.c sched/core / kcov: avoid kcov_area during task switch 2018-06-15 07:55:24 +09:00
kexec.c kexec: add call to LSM hook in original kexec_load syscall 2018-07-16 12:31:57 -07:00
kexec_core.c kexec: yield to scheduler when loading kimage segments 2018-06-15 07:55:24 +09:00
kexec_file.c treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
kexec_internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kmod.c
kprobes.c kprobes: Replace %p with other pointer types 2018-06-21 17:33:42 +02:00
ksysfs.c
kthread.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 11:25:07 -07:00
latencytop.c
Makefile kbuild: move bin2c back to scripts/ from scripts/basic/ 2018-07-18 01:18:05 +09:00
memremap.c libnvdimm-for-4.19_dax-memory-failure 2018-08-25 18:43:59 -07:00
module-internal.h modsign: log module name in the event of an error 2018-07-02 11:36:17 +02:00
module.c module: use relative references for __ksymtab entries 2018-08-22 10:52:47 -07:00
module_signing.c modsign: log module name in the event of an error 2018-07-02 11:36:17 +02:00
notifier.c
nsproxy.c
padata.c padata: add SPDX identifier 2018-01-05 18:43:00 +11:00
panic.c Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables 2018-06-14 12:21:18 +09:00
params.c kernel/params.c: downgrade warning for unsafe parameters 2018-04-11 10:28:37 -07:00
pid.c fork: report pid exhaustion correctly 2018-09-20 22:01:11 +02:00
pid_namespace.c Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-04-03 19:15:32 -07:00
profile.c
ptrace.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
range.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
reboot.c PM / reboot: Eliminate race between reboot and suspend 2018-08-06 12:35:20 +02:00
relay.c kernel/relay.c: change return type to vm_fault_t 2018-06-15 07:55:24 +09:00
resource.c libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
rseq.c rseq: uapi: Declare rseq_cs field as union, update includes 2018-07-10 22:18:52 +02:00
seccomp.c audit/stable-4.18 PR 20180605 2018-06-06 16:34:00 -07:00
signal.c Merge branch 'akpm' (patches from Andrew) 2018-08-22 12:34:08 -07:00
smp.c cpu/hotplug: Fix SMT supported evaluation 2018-08-07 12:25:30 +02:00
smpboot.c smpboot: Remove cpumask from the API 2018-07-03 09:20:44 +02:00
smpboot.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
softirq.c nohz: Fix missing tick reprogram when interrupting an inline softirq 2018-08-03 15:52:10 +02:00
stacktrace.c
stop_machine.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 11:25:07 -07:00
sys.c kernel/sys.c: remove duplicated include 2018-09-20 22:01:11 +02:00
sys_ni.c Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 10:17:09 -07:00
sysctl.c ANDROID: sched: Unconditionally honor sync flag for energy-aware wakeups 2018-10-26 12:14:32 +01:00
sysctl_binary.c staging: irda: remove remaining remants of irda code removal 2018-04-16 11:26:49 +02:00
task_work.c locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-12-17 13:57:15 +01:00
taskstats.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
test_kprobes.c kprobes: Remove jprobe API implementation 2018-06-21 12:33:05 +02:00
torture.c torture: Keep old-school dmesg format 2018-06-25 11:30:10 -07:00
tracepoint.c tracepoint: Fix tracepoint array element size mismatch 2018-10-17 15:35:29 -04:00
tsacct.c
ucount.c headers: untangle kmemleak.h from mm.h 2018-04-05 21:36:27 -07:00
uid16.c fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers 2018-04-02 20:15:59 +02:00
uid16.h kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c 2018-04-02 20:15:30 +02:00
umh.c umh: fix race condition 2018-06-07 16:56:28 -04:00
up.c
user-return-notifier.c
user.c userns: use irqsave variant of refcount_dec_and_lock() 2018-08-22 10:52:47 -07:00
user_namespace.c userns: move user access out of the mutex 2018-08-11 02:05:53 -05:00
utsname.c uts: create "struct uts_namespace" from kmem_cache 2018-04-11 10:28:35 -07:00
utsname_sysctl.c sys: don't hold uts_sem while accessing userspace memory 2018-08-11 02:05:53 -05:00
watchdog.c watchdog: Mark watchdog touch functions as notrace 2018-08-30 12:56:40 +02:00
watchdog_hld.c watchdog: Mark watchdog touch functions as notrace 2018-08-30 12:56:40 +02:00
workqueue.c watchdog: Mark watchdog touch functions as notrace 2018-08-30 12:56:40 +02:00
workqueue_internal.h workqueue: Set worker->desc to workqueue name by default 2018-05-18 08:47:13 -07:00