linux-kernel - [PATCH 0/4] sched / idle: Reduce the number of branches in the idle loop

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

Date:	Mon, 04 May 2015 15:54:43 +0200
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Peter Zijlstra <peterz@...radead.org>,
	Linux PM list <linux-pm@...r.kernel.org>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Daniel Lezcano <daniel.lezcano@...aro.org>
Subject: [PATCH 0/4] sched / idle: Reduce the number of branches in the idle loop

Hi,

The "reflect" variable that had to be added to cpuidle_idle_call() to fix a
regression during the 4.0 cycle has bothered me a bit since then and guess
what?  It is not necessary.

After the last regression fix related to tick_broadcast_exit() I realized
that it should be possible to eliminate this variable by splitting
cpuidle_idle_call() into smaller routines and reordering the code in
question which is done by this patch series.

It also gets rid of one more redundant check while at it.

[1/4] Move the default idle call code into a separate function.
[2/4] Make cpuidle_reflect() check the sign of its index arg.
[3/4] Eliminate the "reflect" check from cpuidle_idle_call().
[4/4] Eliminate a redundant check of the cpuidle_enter() return value.

All on top of 4.1-rc2.

Thanks!

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
--
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/