From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25729C433E1 for ; Thu, 18 Jun 2020 08:37:16 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D9ECB214DB for ; Thu, 18 Jun 2020 08:37:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="r6xypbAG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D9ECB214DB Authentication-Results: mail.kernel.org; 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Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jlq2t-0001z4-Dc; Thu, 18 Jun 2020 08:37:15 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jlq2q-0001xs-LE for linux-arm-kernel@lists.infradead.org; Thu, 18 Jun 2020 08:37:14 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 818F431B; Thu, 18 Jun 2020 01:37:11 -0700 (PDT) Received: from [10.37.12.69] (unknown [10.37.12.69]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CEF343F6CF; Thu, 18 Jun 2020 01:37:09 -0700 (PDT) Subject: Re: [PATCH v8 3/9] firmware: arm_scmi: Add notification dispatch and delivery To: Cristian Marussi , Sudeep Holla References: <20200520081118.54897-1-cristian.marussi@arm.com> <20200520081118.54897-4-cristian.marussi@arm.com> <20200608170346.GD13622@bogus> <20200617233105.GB9236@e119603-lin.cambridge.arm.com> From: Lukasz Luba Message-ID: <20bf2b0b-c6bc-1010-0512-e970982f9e79@arm.com> Date: Thu, 18 Jun 2020 09:37:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200617233105.GB9236@e119603-lin.cambridge.arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200618_013712_736689_B6C4ABC2 X-CRM114-Status: GOOD ( 17.75 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: james.quinlan@broadcom.com, dave.martin@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jonathan.Cameron@Huawei.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 6/18/20 12:31 AM, Cristian Marussi wrote: > On Mon, Jun 08, 2020 at 06:03:46PM +0100, Sudeep Holla wrote: >> On Wed, May 20, 2020 at 09:11:12AM +0100, Cristian Marussi wrote: >>> Add core SCMI Notifications dispatch and delivery support logic which is >>> able, at first, to dispatch well-known received events from the RX ISR to >>> the dedicated deferred worker, and then, from there, to final deliver the >>> events to the registered users' callbacks. >>> >>> Dispatch and delivery is just added here, still not enabled. >>> >>> Reviewed-by: Jonathan Cameron >>> Signed-off-by: Cristian Marussi >>> --- >>> drivers/firmware/arm_scmi/notify.c | 354 ++++++++++++++++++++++++++++- >>> drivers/firmware/arm_scmi/notify.h | 10 + >>> 2 files changed, 362 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c >>> index 7cf61dbe2a8e..d582f71fde5b 100644 >>> --- a/drivers/firmware/arm_scmi/notify.c >>> +++ b/drivers/firmware/arm_scmi/notify.c >> >> [...] >> >>> @@ -1085,6 +1422,12 @@ int scmi_notification_init(struct scmi_handle *handle) >>> ni->gid = gid; >>> ni->handle = handle; >>> >>> + ni->notify_wq = alloc_workqueue("scmi_notify", >>> + WQ_UNBOUND | WQ_FREEZABLE | WQ_SYSFS, >>> + 0); >> >> What's the use of WQ_SYSFS for SCMI notifications ? Do we need it ? >> > > Lukasz asked for it, when we were talking about workqueues' priorities configurability. > (not implemented in this series) I confirm, I've asked if we can have a mechanism to control these workqueues. They will be running concurrently with other CFS tasks which could cause delays for them. They could also be scheduled on a random core: big or little (depends on its utilization) but maybe we would like to pin them explicitly to some cores, i.e little only. We have also discussed a possible mechanism based on RT threads (which could avoid CFS delays), but that would require a lot of changes, so this flag here gives us some control. But if you decide to remove this flag, we would probably find a solution using uclamp or similar when needed. Regards, Lukasz > > Thanks > > Cristian >> -- >> Regards, >> Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel