From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8CE6F340281 for ; Thu, 18 Dec 2025 13:49:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766065802; cv=none; b=taWb6KiKebOr7kfmMF6PZvRkBCwAMT3/QqMKlTHykZT8o0/b6XCT9xSs+c5VI9zL/t34PFPfKi3F5uhSS60YVuLa5ntN0QtyWZ/5lrDk9W2mvsIh/Lsev2mOBc+xtrAXv3If4n8zvX6gv3jisocchL4WWFhQW3sN2URuPPzTunc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766065802; c=relaxed/simple; bh=EYFnrykSkLD+1zxsK/S+9J0BgGIcRi4SBSFybLPI/rY=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=emgdnqqjpUVysedKCKDTHIgK/8PiBlDAr/mBa4PUgbTlhrTrO3mdDUZ/PDI/IXHtiXOE26j6Qi2tg1cum62GOAvjhhifNuh3suK0ApFLs4sYeaoRBHLzgQKmSYL8JnsDFFToJVqMTRqTEYSRqrTmj5fLSsiMvbyQGy5zra9vCIU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com 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) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500011.china.huawei.com (7.191.174.215) To dubpeml100005.china.huawei.com (7.214.146.113) 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); > +}