linux-kernel - [PATCH 1/2] cpuidle: governors: Drop redundant checks related to PM QoS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Wed, 30 May 2018 13:41:09 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Linux PM <linux-pm@...r.kernel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Ramesh Thomas <ramesh.thomas@...el.com>
Subject: [PATCH 1/2] cpuidle: governors: Drop redundant checks related to PM QoS

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

PM_QOS_RESUME_LATENCY_NO_CONSTRAINT is defined as the 32-bit integer
maximum, so it is not necessary to test the return value of
dev_pm_qos_raw_read_value() against it directly in the menu and
ladder cpuidle governors.

Drop these redundant checks.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/cpuidle/governors/ladder.c |    3 +--
 drivers/cpuidle/governors/menu.c   |    3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

Index: linux-pm/drivers/cpuidle/governors/ladder.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/governors/ladder.c
+++ linux-pm/drivers/cpuidle/governors/ladder.c
@@ -76,8 +76,7 @@ static int ladder_select_state(struct cp
 	int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
 	int resume_latency = dev_pm_qos_raw_read_value(device);
 
-	if (resume_latency < latency_req &&
-	    resume_latency != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
+	if (resume_latency < latency_req)
 		latency_req = resume_latency;
 
 	/* Special case when user has set very strict latency requirement */
Index: linux-pm/drivers/cpuidle/governors/menu.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/governors/menu.c
+++ linux-pm/drivers/cpuidle/governors/menu.c
@@ -304,8 +304,7 @@ static int menu_select(struct cpuidle_dr
 		data->needs_update = 0;
 	}
 
-	if (resume_latency < latency_req &&
-	    resume_latency != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
+	if (resume_latency < latency_req)
 		latency_req = resume_latency;
 
 	/* Special case when user has set very strict latency requirement */