[PATCH 3.16 181/204] sched/topology: Remove FORCE_SD_OVERLAP

From: Ben Hutchings
Date: Thu Dec 28 2017 - 12:20:40 EST


3.16.52-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

commit af85596c74de2fd9abb87501ae280038ac28a3f4 upstream.

Its an obsolete debug mechanism and future code wants to rely on
properties this undermines.

Namely, it would be good to assume that SD_OVERLAP domains have
children, but if we build the entire hierarchy with SD_OVERLAP this is
obviously false.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
kernel/sched/core.c | 2 +-
kernel/sched/features.h | 1 -
2 files changed, 1 insertion(+), 2 deletions(-)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6631,7 +6631,7 @@ static int build_sched_domains(const str
sd = build_sched_domain(tl, cpu_map, attr, sd, i);
if (tl == sched_domain_topology)
*per_cpu_ptr(d.sd, i) = sd;
- if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
+ if (tl->flags & SDTL_OVERLAP)
sd->flags |= SD_OVERLAP;
if (cpumask_equal(cpu_map, sched_domain_span(sd)))
break;
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -56,7 +56,6 @@ SCHED_FEAT(NONTASK_CAPACITY, true)
*/
SCHED_FEAT(TTWU_QUEUE, true)

-SCHED_FEAT(FORCE_SD_OVERLAP, false)
SCHED_FEAT(RT_RUNTIME_SHARE, true)
SCHED_FEAT(LB_MIN, false)