linux/kernel
Dietmar Eggemann 1c4d0672be sched/fair: Change cpu iteration order in find_best_target()
The schedtune task parameter 'boosted' is mapped into the cpu iteration
order. Currently for 'boosted' equal true the iteration starts at the
last cpu (NR_CPUS-1) whereas for 'boosted' equal false it starts at the
first cpu (0).

This only has the desired effect if the cpu topology oerdering matches
the underlying assumption. This e.g. is the case for the
Qc snapdragon 821 with its [L0 L1 b0 b1] cpu topology layout
(L=lower max freq, b=higher max freq). This results in cpus with higher
maximum capacity being given the highest logical cpu ids. However not
all big.LITTLE systems enumerate their cpus in the same way. For example,
the ARM Versatile Express Juno board has 6 cpus for which the default
configuration has topology [L0 b0 b1 L1 L2 L3].

To make this approach independent from the cpu topology layout it now
iterates over the cpus in the order of the sched_groups of the EAS
sched_domain (sd_ea). The order of cpu iteration is different for the
different cpu types in case the cpu is used to dereference sd_ea.

Considering the Qc snapdragon 821 again, for cpu L0 and L1 the order is
'b0->b1->L0->L1' whereas for b0 and b1 the order is 'b0->b1->L0->L1'.

This approach does not allow the exact same iteration order as with the
currently used flat iteration over [0 .. NR_CPUS-1] but the cpus
are ordered by the original cpu capacity.

The cpu iteration is now done in the sd_ea sched_group order required by
the 'boosted' value ['L0->L1->b0->b1'/'b0->b1->L0->L1'] rather than
forward/backward over the flat cpu space ['L0->L1->b0->b1'/
'b1->b0->L1->L0'].

Change-Id: I8fbe2073dedd2ecb1c750620c6000c11a5ff4358
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
(cherry picked from commit a0c6a4272c3968c0ff50d3fed65f5865b72d777b)
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
2017-06-21 16:37:32 +05:30
..
bpf bpf, inode: disallow userns mounts 2016-06-24 10:18:17 -07:00
configs kconfig: tinyconfig: provide whole choice blocks to avoid warnings 2016-09-24 10:07:42 +02:00
debug Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-01-09 12:01:35 +08:00
events Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-05-04 12:01:39 +08:00
gcov gcov: add support for GCC 5.1 2015-06-30 19:44:57 -07:00
irq genirq: Fix chained interrupt data ordering 2017-05-25 14:30:17 +02:00
livepatch livepatch: x86: fix relocation computation with kASLR 2015-11-11 17:36:04 +01:00
locking Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2016-12-20 13:48:11 +08:00
power UPSTREAM: PM / sleep: make PM notifiers called symmetrically 2017-05-01 15:02:13 +05:30
printk Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-02-24 12:03:21 +08:00
rcu Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2016-12-12 22:17:37 +08:00
sched sched/fair: Change cpu iteration order in find_best_target() 2017-06-21 16:37:32 +05:30
time Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-01-13 12:01:52 +08:00
trace Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-05-26 12:03:29 +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
audit_fsnotify.c audit: clean simple fsnotify implementation 2015-08-06 16:14:53 -04:00
audit_tree.c audit: audit_tree_match can be boolean 2015-11-04 08:23:51 -05:00
audit_watch.c audit: fix exe_file access in audit_exe_compare 2016-09-24 10:07:36 +02:00
audit.c BACKPORT: audit: consistently record PIDs with task_tgid_nr() 2016-10-12 17:34:22 +05:30
audit.h audit: audit_tree_match can be boolean 2015-11-04 08:23:51 -05:00
auditfilter.c audit: fix comment block whitespace 2015-11-04 08:23:51 -05:00
auditsc.c BACKPORT: audit: consistently record PIDs with task_tgid_nr() 2016-10-12 17:34:22 +05:30
backtracetest.c
bounds.c
capability.c exec: Ensure mm->user_ns contains the execed files 2017-01-06 11:16:14 +01:00
cgroup_freezer.c cgroup: fix handling of multi-destination migration from subtree_control enabling 2015-12-03 10:18:21 -05:00
cgroup_pids.c cgroup_pids: don't account for the root cgroup 2015-12-03 10:18:21 -05:00
cgroup.c Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-04-23 12:02:14 +08:00
compat.c
configs.c
context_tracking.c context_tracking: avoid irq_save/irq_restore on guest entry and exit 2015-11-10 12:06:23 +01:00
cpu_pm.c kernel/cpu_pm: fix cpu_cluster_pm_exit comment 2015-09-03 02:42:20 +02:00
cpu.c Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-01-13 12:01:52 +08:00
cpuset.c cgroup: Remove leftover instances of allow_attach 2016-10-25 21:53:04 +08:00
crash_dump.c
cred.c cred: Reject inodes with invalid ids in set_create_file_as() 2016-09-15 08:27:49 +02:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c FIXUP: sched/tune: fix accounting for runnable tasks 2016-09-14 14:59:32 +05:30
extable.c kernel/extable.c: remove duplicated include 2015-09-10 13:29:01 -07:00
fork.c Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-05-26 12:03:29 +08:00
freezer.c
futex_compat.c ptrace: use fsuid, fsgid, effective creds for fs access checks 2016-02-25 12:01:16 -08:00
futex.c Merge tag 'v4.4.56' into linux-linaro-lsk-v4.4 2017-03-23 12:00:54 +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 jump_labels: API for flushing deferred jump label updates 2017-01-19 20:17:19 +01:00
kallsyms.c
kcmp.c ptrace: use fsuid, fsgid, effective creds for fs access checks 2016-02-25 12:01:16 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec_core.c kexec: use file name as the output message prefix 2015-11-06 17:50:42 -08:00
kexec_file.c kexec: fix double-free when failing to relocate the purgatory 2016-09-24 10:07:36 +02:00
kexec_internal.h kexec: split kexec_file syscall code to kexec_file.c 2015-09-10 13:29:01 -07:00
kexec.c kexec: use file name as the output message prefix 2015-11-06 17:50:42 -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 tracing/kprobes: Enforce kprobes teardown after testing 2017-05-25 14:30:17 +02:00
ksysfs.c kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
kthread.c BACKPORT: kthread: allow to cancel kthread work 2017-06-21 16:34:04 +05:30
latencytop.c
Makefile sys_membarrier(): system-wide memory barrier (generic, x86) 2015-09-11 15:21:34 -07:00
membarrier.c Fix: Disable sys_membarrier when nohz_full is enabled 2017-03-12 06:37:26 +01:00
memremap.c mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done} 2017-01-19 20:17:18 +01:00
module_signing.c KEYS: Merge the type-specific data with the payload data 2015-10-21 15:18:36 +01:00
module-internal.h
module.c module: Invalidate signatures on force-loaded modules 2016-08-20 18:09:27 +02:00
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 padata: free correct variable 2017-05-20 14:27:02 +02:00
panic.c Revert "panic: Add board ID to panic output" 2016-08-18 18:56:03 +05:30
params.c Nothing exciting, minor tweaks and cleanups. 2015-11-09 15:53:39 -08:00
pid_namespace.c pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes 2017-05-25 14:30:11 +02:00
pid.c pidns: fix NULL dereference in __task_pid_nr_ns() 2015-11-24 12:03:55 -08:00
profile.c mm: rename alloc_pages_exact_node() to __alloc_pages_node() 2015-09-08 15:35:28 -07:00
ptrace.c ptrace: fix PTRACE_LISTEN race corrupting task->state 2017-04-12 12:38:33 +02:00
range.c
reboot.c kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
relay.c kernel/relay.c: use kvfree() in relay_free_page_array() 2015-06-30 19:44:59 -07:00
resource.c kernel/resource.c: fix muxed resource handling in __request_region() 2016-03-03 15:07:29 -08:00
seccomp.c seccomp: always propagate NO_NEW_PRIVS on tsync 2016-03-03 15:07:25 -08:00
signal.c kernel/signal.c: unexport sigsuspend() 2015-11-20 16:17:32 -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: remove stop_machine() Kconfig dependency 2015-12-12 10:15:34 -08:00
sys_ni.c mm: mlock: add new mlock system call 2015-11-05 19:34:48 -08:00
sys.c BACKPORT: timer: convert timer_slack_ns from unsigned long to u64 2016-07-11 12:43:04 +05:30
sysctl_binary.c fs/coredump: prevent fsuid=0 dumps into user-controlled directories 2016-04-12 09:08:58 -07:00
sysctl.c sched: Remove sysctl_sched_is_big_little 2017-06-21 16:37:28 +05:30
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_namespace.c capabilities: ambient capabilities 2015-09-04 16:54:41 -07:00
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog.c Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android 2017-01-09 12:01:35 +08:00
workqueue_internal.h
workqueue.c workqueue: fix rebind bound workers warning 2016-05-18 17:06:50 -07:00