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From: "Sexton, Rory" <rory.sexton@intel.com>
To: dev@dpdk.org, david.hunt@intel.com
Cc: "Sexton, Rory" <rory.sexton@intel.com>
Subject: [dpdk-dev] [PATCH v1 2/3] examples/vm_power_manager: Allowing power managing of idle cores
Date: Mon, 18 May 2020 11:12:10 +0100	[thread overview]
Message-ID: <20200518101211.26025-2-rory.sexton@intel.com> (raw)
In-Reply-To: <20200518101211.26025-1-rory.sexton@intel.com>

This change is required to allow the branch ratio algorithm to
power manage cores with no workload running on them. This is
useful both when idle cores don't use C-states and for a number of
hyperthreading scenarios.
---
 examples/vm_power_manager/oob_monitor_x86.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/examples/vm_power_manager/oob_monitor_x86.c b/examples/vm_power_manager/oob_monitor_x86.c
index 3c514475f..a5b1c168c 100644
--- a/examples/vm_power_manager/oob_monitor_x86.c
+++ b/examples/vm_power_manager/oob_monitor_x86.c
@@ -96,12 +96,12 @@ apply_policy(int core)
 	g_branch_misses = miss_diff;
 
 	if (hits_diff < (INTERVAL*100)) {
-		/* Likely no workload running on this core. Skip. */
-		return -1.0;
+		/* Likely no workload running on this core. */
+		ratio = 0.0;
+	} else {
+		ratio = (float)miss_diff * (float)100 / (float)hits_diff;
 	}
 
-	ratio = (float)miss_diff * (float)100 / (float)hits_diff;
-
 	/*
 	 * Store the last few directions that the ratio indicates
 	 * we should take. If there's on 'up', then we scale up
-- 
2.17.1


  reply	other threads:[~2020-05-18 10:34 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-18 10:12 [dpdk-dev] [PATCH v1 1/3] examples/vm_power_manager: Make branch ratio threshold per core Sexton, Rory
2020-05-18 10:12 ` Sexton, Rory [this message]
2020-05-18 10:12 ` [dpdk-dev] [PATCH v1 3/3] doc: update vm_power_manager cmdline options in doc Sexton, Rory
2020-05-18 10:59   ` Sexton, Rory

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