From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH 1/2] PM / Domains: Don't measure ->start|stop() latency in system PM callbacks Date: Fri, 23 Oct 2015 11:48:11 -0700 Message-ID: <7hd1w5pgk4.fsf@deeprootsystems.com> References: <1444921326-22574-1-git-send-email-ulf.hansson@linaro.org> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-pa0-f53.google.com ([209.85.220.53]:34351 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753574AbbJWSsN (ORCPT ); Fri, 23 Oct 2015 14:48:13 -0400 Received: by padhk11 with SMTP id hk11so125292895pad.1 for ; Fri, 23 Oct 2015 11:48:13 -0700 (PDT) In-Reply-To: <1444921326-22574-1-git-send-email-ulf.hansson@linaro.org> (Ulf Hansson's message of "Thu, 15 Oct 2015 17:02:06 +0200") Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Ulf Hansson Cc: "Rafael J. Wysocki" , linux-pm@vger.kernel.org, Len Brown , Pavel Machek , Geert Uytterhoeven , Lina Iyer , Krzysztof Kozlowski Ulf Hansson writes: > Measure latency does by itself contribute to an increased latency, thus we > should avoid it when it isn't needed. > > Genpd measures latencies in the system PM phase for the ->start|stop() > callbacks and is thus affecting the system PM suspend/resume time. > Moreover these latencies are validated only at runtime PM suspend/resume. > > To this reasoning, let's decide to leave these measurements out of the > system PM phase. There should be plenty of occasions during runtime PM to > perform these measurements anyway. > > Signed-off-by: Ulf Hansson Acked-by: Kevin Hilman