From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
To: "Peter Zijlstra (Intel)" <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Len Brown <len.brown@intel.com>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Aubrey Li <aubrey.li@linux.intel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Ricardo Neri <ricardo.neri@intel.com>,
Quentin Perret <qperret@google.com>,
"Joel Fernandes (Google)" <joel@joelfernandes.org>,
linux-kernel@vger.kernel.org,
Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
Aubrey Li <aubrey.li@intel.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>
Subject: [PATCH v3 2/6] sched/fair: Optimize checking for group_asym_packing
Date: Thu, 13 May 2021 08:49:05 -0700 [thread overview]
Message-ID: <20210513154909.6385-3-ricardo.neri-calderon@linux.intel.com> (raw)
In-Reply-To: <20210513154909.6385-1-ricardo.neri-calderon@linux.intel.com>
sched_asmy_prefer(a, b) returns true if the priority of cpu a is bigger
than the priority of b. dst_cpu belongs to the local group. It follows
that its priority is equal or less than the priority of the preferred
CPU of the local group. Thus, sched_asmy_prefer() always returns false
when called on the local group.
By checking local_group, we can avoid additional checks and invoking
sched_asmy_prefer() when it is not needed.
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Quentin Perret <qperret@google.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
---
Changes since v2:
* Reworded commit message for clarity. (Peter Z)
Changes since v1:
* None
---
kernel/sched/fair.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 161b92aa1c79..96b023432a1c 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8507,7 +8507,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
}
/* Check if dst CPU is idle and preferred to this group */
- if (env->sd->flags & SD_ASYM_PACKING &&
+ if (!local_group && env->sd->flags & SD_ASYM_PACKING &&
env->idle != CPU_NOT_IDLE &&
sgs->sum_h_nr_running &&
sched_asym_prefer(env->dst_cpu, group->asym_prefer_cpu)) {
--
2.17.1
next prev parent reply other threads:[~2021-05-13 15:50 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-13 15:49 [PATCH v3 0/6] sched/fair: Fix load balancing of SMT siblings with ASYM_PACKING Ricardo Neri
2021-05-13 15:49 ` [PATCH v3 1/6] sched/topology: Introduce sched_group::flags Ricardo Neri
2021-05-13 15:49 ` Ricardo Neri [this message]
2021-05-13 15:49 ` [PATCH v3 3/6] sched/fair: Provide update_sg_lb_stats() with sched domain statistics Ricardo Neri
2021-05-13 15:49 ` [PATCH v3 4/6] sched/fair: Carve out logic to mark a group for asymmetric packing Ricardo Neri
2021-05-17 14:21 ` Dietmar Eggemann
2021-05-18 19:18 ` Ricardo Neri
2021-05-13 15:49 ` [PATCH v3 5/6] sched/fair: Consider SMT in ASYM_PACKING load balance Ricardo Neri
2021-05-14 9:47 ` Peter Zijlstra
2021-05-15 2:14 ` Ricardo Neri
2021-05-18 19:07 ` Ricardo Neri
2021-05-19 9:59 ` Peter Zijlstra
2021-05-19 11:09 ` Nicholas Piggin
2021-05-19 12:05 ` Srikar Dronamraju
2021-05-17 15:18 ` Dietmar Eggemann
2021-05-18 19:10 ` Ricardo Neri
2021-05-17 22:28 ` Joel Fernandes
2021-05-17 22:34 ` Joel Fernandes
2021-05-13 15:49 ` [PATCH v3 6/6] x86/sched: Enable SMT checks for asymmetric packing in load balancing Ricardo Neri
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