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From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Date: Wed, 20 Jun 2018 22:32:49 +0530
Subject: [PATCH] sched/numa: Remove unused task_capacity from 'struct
 numa_stats'

References: bnc#1101669 optimise numa balancing for fast migrate
Patch-mainline: v4.19-rc1
Git-commit: 10864a9e222048a862da2c21efa28929a4dfed15

The task_capacity field in 'struct numa_stats' is redundant.
Also move nr_running for better packing within the struct.

No functional changes.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25308.6     25377.3     0.271
1     72964       72287       -0.92

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1529514181-9842-9-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 kernel/sched/fair.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a5d673832455..d1eb02bf9106 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1478,14 +1478,12 @@ static unsigned long capacity_of(int cpu);
 
 /* Cached statistics for all CPUs within a node */
 struct numa_stats {
-	unsigned long nr_running;
 	unsigned long load;
 
 	/* Total compute capacity of CPUs on a node */
 	unsigned long compute_capacity;
 
-	/* Approximate capacity in terms of runnable tasks on a node */
-	unsigned long task_capacity;
+	unsigned int nr_running;
 	int has_free_capacity;
 };
 
@@ -1523,9 +1521,9 @@ static void update_numa_stats(struct numa_stats *ns, int nid)
 	smt = DIV_ROUND_UP(SCHED_CAPACITY_SCALE * cpus, ns->compute_capacity);
 	capacity = cpus / smt; /* cores */
 
-	ns->task_capacity = min_t(unsigned, capacity,
+	capacity = min_t(unsigned, capacity,
 		DIV_ROUND_CLOSEST(ns->compute_capacity, SCHED_CAPACITY_SCALE));
-	ns->has_free_capacity = (ns->nr_running < ns->task_capacity);
+	ns->has_free_capacity = (ns->nr_running < capacity);
 }
 
 struct task_numa_env {