linux-kernel - [PATCH v3 4/4] thermal: power_allocator: exit early if there are no cooling devices

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

Date:	Mon, 17 Aug 2015 18:36:48 +0100
From:	Javi Merino <javi.merino@....com>
To:	linux-pm@...r.kernel.org
Cc:	dmitry.torokhov@...il.com, cywang@...omium.org,
	linux-kernel@...r.kernel.org, punit.agrawal@....com,
	djkurtz@...omium.org, Javi Merino <javi.merino@....com>,
	Zhang Rui <rui.zhang@...el.com>,
	Eduardo Valentin <edubezval@...il.com>
Subject: [PATCH v3 4/4] thermal: power_allocator: exit early if there are no cooling devices

Don't waste cycles in the power allocator governor's throttle function
if there are no cooling devices and exit early.

This commit doesn't change any functionality, but should provide better
performance for the odd case of a thermal zone with trip points but
without cooling devices.

Cc: Zhang Rui <rui.zhang@...el.com>
Cc: Eduardo Valentin <edubezval@...il.com>
Signed-off-by: Javi Merino <javi.merino@....com>
---
 drivers/thermal/power_allocator.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c
index 6dcc4fedd4f2..6b536ffd5ef6 100644
--- a/drivers/thermal/power_allocator.c
+++ b/drivers/thermal/power_allocator.c
@@ -291,6 +291,11 @@ static int allocate_power(struct thermal_zone_device *tz,
 		}
 	}
 
+	if (!num_actors) {
+		ret = -ENODEV;
+		goto unlock;
+	}
+
 	/*
 	 * We need to allocate five arrays of the same size:
 	 * req_power, max_power, granted_power, extra_actor_power and
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/