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 7B807C04FFE for ; Tue, 14 May 2024 14:29:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:References:CC:To:From: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=dx8pBXYLvjP+Mcmido/tnLRWvDr+RhqFoPWb60rEBNo=; b=yaVcIX0Z8HWrKE q4VWn55TGaLCfrPFT1wpc/VVB/DE0GRD/grG+MbYShngCTIX0crVr/dJmPVY4xY8csbB+uSbJr0kZ wQiKEQqlzynV9peW/gf0csjEmLHTgxC5LH59OR6x8wX/YT3DSomhDXG1au86PY8SIEQCgK3x9D4Vd 9dDXoLgst4nG6F/ZGkdLFUNx2dD8kycuEKklKRwT94gS7ULdaK8rqje8XlrAz8tm1eCzrHwBdUXMk Wdn5b0t0w/OBdCZUU19AMP2h4oiRJnBgufflnVaSH3zCgsSUcpDl3L8bEICZghZZH4Cg4HBcPyx4P wbz6D1ta2br1vl2xbPXw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1s6tA1-0000000GBbn-1UnE; Tue, 14 May 2024 14:29:45 +0000 Received: from lelv0142.ext.ti.com ([198.47.23.249]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1s6t9v-0000000GBb7-24K0 for linux-arm-kernel@lists.infradead.org; Tue, 14 May 2024 14:29:43 +0000 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 44EETT5C017469; Tue, 14 May 2024 09:29:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1715696969; bh=J+2Dx63m3rl/avn6WlrRF0ewymLz6wPP3CDkECjxYqo=; h=Date:Subject:From:To:CC:References:In-Reply-To; b=N2P4OVPFpRWLPxmxd6L2IzL3sr2/+S0SoG5DtOlW+KgBhsj2z7rVmvjHp+9lRF01u sPe+mymPxjfx9o1qz9bOSCG0kK5ku+EQvqEklnguu2z1yUqBwajSa+aqsUCKBAjxb3 cU2Wu/AhVPVlofozCvNXwiJA0rztOCryB/goprHE= Received: from DLEE108.ent.ti.com (dlee108.ent.ti.com [157.170.170.38]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 44EETT57061774 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 14 May 2024 09:29:29 -0500 Received: from DLEE101.ent.ti.com (157.170.170.31) by DLEE108.ent.ti.com (157.170.170.38) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Tue, 14 May 2024 09:29:29 -0500 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DLEE101.ent.ti.com (157.170.170.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Tue, 14 May 2024 09:29:29 -0500 Received: from [172.24.227.193] (devarsht.dhcp.ti.com [172.24.227.193] (may be forged)) by lelvsmtp6.itg.ti.com (8.15.2/8.15.2) with ESMTP id 44EETNm1001116; Tue, 14 May 2024 09:29:24 -0500 Message-ID: <0eee0424-f177-808f-3a86-499443155ddb@ti.com> Date: Tue, 14 May 2024 19:59:23 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH] arm64: dts: ti: k3-am62x-sk-common: Reserve 128MiB of global CMA Content-Language: en-US From: Devarsh Thakkar To: Andrew Davis , Nishanth Menon , "Raghavendra, Vignesh" CC: , , , , , , , , , , , , Brandon , "Pothukuchi, Vijay" , "Etheridge, Darren" References: <20230803111455.811339-1-devarsht@ti.com> <20230805193355.o657pwbq2w3tciui@vehicular> <9b61e8a0-fec0-b33f-259c-c744aa5a88b9@ti.com> <18bb47b8-c441-00b1-7ac7-f9038dffedc4@ti.com> In-Reply-To: X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240514_072939_749428_E37ACBE0 X-CRM114-Status: GOOD ( 10.99 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Andrew, Vignesh, Nishanth, On 08/08/23 13:44, Devarsh Thakkar wrote: [...] >>>>> Reserve 128MiB of global CMA which is also marked as re-usable >>>>> so that OS can also use the same if peripheral drivers are not using the >>>>> same. >>>>> I wanted to re-initiate discussion on this. Per discussion with few of the maintainers in OSS 2023 Summit, the suggestion was either to have MMU in the devices or use the CMA region as done with this patch. There was not much traction for the idea/suggestion to have some updates in CMA API to dynamically increase the CMA region per the requirement (for e.g. move the MIGRATE_MOVABLE pages to CMA area dynamically). Also I see some efforts in the past made on that direction for introducing CMA_AGGRESSIVE Kconfig to allocate from ZONE_MOVEABLE but were not accepted [1] and nevertheless it still requires CMA region to be available to begin with and only gives a bit of extra margin for the CMA. My vote is still to use global cma region with re-usable flag (as done with this patch) and 128 MiB is well estimated per the use-cases AM62x EVM is meant to cater (the vendor specific kernel has been using it) and is very much needed to provided out-of-box experience as otherwise basic display and camera use-cases don't work out-of-box. Besides I see many other boards [presumably mmu-less] using a similar approach : $git grep linux,cma-default arch/ | wc 36 72 2538 Kindly let us know your opinion on this if we are aligned to proceed with this approach or not. [1]: https://lore.kernel.org/all/20141107070655.GA3486@bbox/ https://linux-mm.kvack.narkive.com/LCGSAqAp/patch-0-4-cma-aggressive-make-cma-memory-be-more-aggressive-about-allocation Regards Devarsh _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel