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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 08FE2D6D226 for ; Thu, 18 Dec 2025 13:50:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=j3NR3D0pcqoKjUc5PYOsd4k3CDAuEeHXW3s7b2AXN5E=; b=ATEAS3WQ4yc8X+8JaYwEv5Kf7g 2IWUzpatb/2//wfG/MZ9IZnwhu0iIOac1wA5mlL3Zdt8lGe1ecpbFvMefgZ8Crfbh/ImS1CHkkS1Z W3LaF6eGUbQzMgGqbz7RlZpjJF1DB0zjBFSBG2YqFX6IYYOAwzQprOvq40lRGVkD/n7XtZph0jVGc suBlYK6XmNB9EYqBWJEdqp04QzCcyFb+Ja5aUGwn+76kT2Eon//PRGuuIxnaAhcl1kweLYVgOceBH 78rGvN19S4Ac6Yv/U42ddu4sWvYb8dSuZSs027e49mw2S7oo/6Qpt7fGpkOC19QWsNvvwG7Dsomlc wC4E6Ruw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vWEOK-00000008ZAQ-3EyN; Thu, 18 Dec 2025 13:50:04 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vWEOH-00000008Z9c-15li for linux-arm-kernel@lists.infradead.org; Thu, 18 Dec 2025 13:50:03 +0000 Received: from mail.maildlp.com (unknown [172.18.224.150]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4dXBqF1VwqzHnH2q; Thu, 18 Dec 2025 21:49:29 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 71EAA4056A; Thu, 18 Dec 2025 21:49:56 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Thu, 18 Dec 2025 13:49:55 +0000 Date: Thu, 18 Dec 2025 13:49:53 +0000 From: Jonathan Cameron To: James Morse CC: , , D Scott Phillips OS , , , , , , Jamie Iles , "Xin Hao" , , , , David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , , , Gavin Shan , Ben Horgan , , , Punit Agrawal Subject: Re: [RFC PATCH 24/38] arm_mpam: resctrl: Allow resctrl to allocate monitors Message-ID: <20251218134953.000064b1@huawei.com> In-Reply-To: <20251205215901.17772-25-james.morse@arm.com> References: <20251205215901.17772-1-james.morse@arm.com> <20251205215901.17772-25-james.morse@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml500011.china.huawei.com (7.191.174.215) To dubpeml100005.china.huawei.com (7.214.146.113) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251218_055001_447620_3FD9DD2C X-CRM114-Status: GOOD ( 18.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 5 Dec 2025 21:58:47 +0000 James Morse wrote: > When resctrl wants to read a domain's 'QOS_L3_OCCUP', it needs > to allocate a monitor on the corresponding resource. Monitors are > allocated by class instead of component. > > MBM monitors are much more complicated, if there are enough monitors, > they will be pre-allocated and free-running. If ABMC is in use instead > then 'some' are pre-allocated in a different way, and need assigning. > > Add helpers to allocate a CSU monitor. These helper return an out > of range value for MBM counters. > > Allocating a montitor context is expected to block until hardware > resources become available. This only makes sense for QOS_L3_OCCUP > as unallocated MBM counters are losing data. > > Signed-off-by: James Morse > --- > Since ABMC got merged it may be possible to remove the monitor alloc > call for MBM counters from resctrl as this work is now done by ABMC's > assign call. > --- > drivers/resctrl/mpam_internal.h | 14 ++++++- > drivers/resctrl/mpam_resctrl.c | 68 +++++++++++++++++++++++++++++++++ > include/linux/arm_mpam.h | 4 ++ > 3 files changed, 85 insertions(+), 1 deletion(-) > > diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c > index 22ad5dd3c383..a2b238d47117 100644 > --- a/drivers/resctrl/mpam_resctrl.c > +++ b/drivers/resctrl/mpam_resctrl.c > + > +void resctrl_arch_mon_ctx_free(struct rdt_resource *r, > + enum resctrl_event_id evtid, void *arch_mon_ctx) > +{ > + u32 mon_idx = *(u32 *)arch_mon_ctx; > + > + kfree(arch_mon_ctx); > + arch_mon_ctx = NULL; Why is this useful? Updating the local pointer copy which is not used again. Maybe I need more coffee. > + > + resctrl_arch_mon_ctx_free_no_wait(evtid, mon_idx); > +}