Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754558AbbDUKSc (ORCPT ); Tue, 21 Apr 2015 06:18:32 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:55753 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753742AbbDUKSa (ORCPT ); Tue, 21 Apr 2015 06:18:30 -0400 Message-ID: In-Reply-To: <553609CA.8000806@intel.com> References: <1427204440-3533-1-git-send-email-adrian.hunter@intel.com> <1427204440-3533-2-git-send-email-adrian.hunter@intel.com> <03394129c3ef5958dcfbe3726959ecd1.squirrel@www.codeaurora.org> <553609CA.8000806@intel.com> Date: Tue, 21 Apr 2015 10:18:27 -0000 Subject: Re: [RFC PATCH 1/4] PM / QoS: Add pm_qos_cancel_request_lazy() that doesn't sleep From: "Dov Levenglick" To: "Adrian Hunter" Cc: "Dov Levenglick" , "Ulf Hansson" , "linux-mmc" , "Rafael J. Wysocki" , "Len Brown" , "Pavel Machek" , "Kevin Hilman" , "Tomeu Vizoso" , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org User-Agent: SquirrelMail/1.4.22-4.el6 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Priority: 3 (Normal) Importance: Normal Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3811 Lines: 112 > On 20/04/15 17:00, Dov Levenglick wrote: >>> Add pm_qos_cancel_request_lazy() which is convenient for >>> contexts that may not sleep. >>> >>> Signed-off-by: Adrian Hunter >>> --- >>> include/linux/pm_qos.h | 2 ++ >>> kernel/power/qos.c | 20 ++++++++++++++++++++ >>> 2 files changed, 22 insertions(+) >>> >>> diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h >>> index 7b3ae0c..f44d353 100644 >>> --- a/include/linux/pm_qos.h >>> +++ b/include/linux/pm_qos.h >>> @@ -126,6 +126,8 @@ void pm_qos_update_request(struct pm_qos_request > *req, >>> s32 new_value); >>> void pm_qos_update_request_timeout(struct pm_qos_request *req, >>> s32 new_value, unsigned long >>> timeout_us); >>> +void pm_qos_cancel_request_lazy(struct pm_qos_request *req, >>> + unsigned int timeout_us); >>> void pm_qos_remove_request(struct pm_qos_request *req); >>> >> >> I think that this could be acheived using existing API if >> pm_qos_update_request_timeout() were to be called with the existing >> timeout value. > > I don't follow what you mean. There is no existing timeout value. > Did you mean existing request value? There is still the difference wrt > cancel_delayed_work_sync. I did mean the existing request value. Thanks. There is also the cancel_delayed_work_sync, however I think that that should be called in any case in order to cancel any other pending timeout changes. > >> Since reading the existing timeout value is missing - and I think would > be >> a useful feature to have for other use-cases - do you agree with such an >> approach? >> >>> int pm_qos_request(int pm_qos_class); >>> diff --git a/kernel/power/qos.c b/kernel/power/qos.c >>> index 97b0df7..ac131cb 100644 >>> --- a/kernel/power/qos.c >>> +++ b/kernel/power/qos.c >>> @@ -517,6 +517,26 @@ void pm_qos_update_request_timeout(struct >>> pm_qos_request *req, s32 new_value, >>> } >>> >>> /** >>> + * pm_qos_cancel_request_lazy - cancels an existing qos request > lazily. >>> + * @req : handle to list element holding a pm_qos request to use >>> + * @timeout_us: the delay before cancelling this qos request in usecs. >>> + * >>> + * After timeout_us, this qos request is cancelled. >>> + */ >>> +void pm_qos_cancel_request_lazy(struct pm_qos_request *req, >>> + unsigned int timeout_us) >>> +{ >>> + if (!req) >>> + return; >>> + if (WARN(!pm_qos_request_active(req), >>> + "%s called for unknown object.", __func__)) >>> + return; >>> + >>> + schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); >>> +} >>> +EXPORT_SYMBOL_GPL(pm_qos_cancel_request_lazy); >>> + >>> +/** >>> * pm_qos_remove_request - modifies an existing qos request >>> * @req: handle to request list element >>> * >>> -- >>> 1.9.1 >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >> >> >> QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora > Forum, >> a Linux Foundation Collaborative Project >> >> >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. 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