Commit 76c389ab authored Mar 03, 2020 by Valentin Schneider Committed by Ingo Molnar Mar 06, 2020

sched/fair: Fix kernel build warning in test_idle_cores() for !SMT NUMA



Building against the tip/sched/core as ff7db0bf ("sched/numa: Prefer
using an idle CPU as a migration target instead of comparing tasks") with
the arm64 defconfig (which doesn't have CONFIG_SCHED_SMT set) leads to:

  kernel/sched/fair.c:1525:20: warning: 'test_idle_cores' declared 'static' but never defined [-Wunused-function]
   static inline bool test_idle_cores(int cpu, bool def);
		      ^~~~~~~~~~~~~~~

Rather than define it in its own CONFIG_SCHED_SMT #define island, bunch it
up with test_idle_cores().

Reported-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
[mgorman@techsingularity.net: Edit changelog, minor style change]
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fixes: ff7db0bf ("sched/numa: Prefer using an idle CPU as a migration target instead of comparing tasks")
Link: https://lkml.kernel.org/r/20200303110258.1092-3-mgorman@techsingularity.net

parent 05289b90

kernel/sched/fair.c

+9 −5

Original line number	Diff line number	Diff line
		@@ -1533,9 +1533,6 @@ static inline bool is_core_idle(int cpu)
		return true;
		}

		/* Forward declarations of select_idle_sibling helpers */
		static inline bool test_idle_cores(int cpu, bool def);

		struct task_numa_env {
		struct task_struct *p;

		@@ -1571,9 +1568,11 @@ numa_type numa_classify(unsigned int imbalance_pct,
		return node_fully_busy;
		}

		#ifdef CONFIG_SCHED_SMT
		/* Forward declarations of select_idle_sibling helpers */
		static inline bool test_idle_cores(int cpu, bool def);
		static inline int numa_idle_core(int idle_core, int cpu)
		{
		#ifdef CONFIG_SCHED_SMT
		if (!static_branch_likely(&sched_smt_present) \|\|
		idle_core >= 0 \|\| !test_idle_cores(cpu, false))
		return idle_core;
		@@ -1584,10 +1583,15 @@ static inline int numa_idle_core(int idle_core, int cpu)
		*/
		if (is_core_idle(cpu))
		idle_core = cpu;
		#endif

		return idle_core;
		}
		#else
		static inline int numa_idle_core(int idle_core, int cpu)
		{
		return idle_core;
		}
		#endif

		/*
		* Gather all necessary information to make NUMA balancing placement

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