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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 D079DC433E0 for ; Tue, 12 Jan 2021 16:35:10 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 75E4D22CBE for ; Tue, 12 Jan 2021 16:35:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75E4D22CBE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject: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=oQyRJks20sZT1Hya6IyNSkfSLMrFODJrQ/roSASeNgE=; b=e9DpKMy2yIRsT8ozWIoAdMBxT 1qFgtsU7obx/T1NrvqW/tcEuVsvIwgqByNLMJ+BvS2wwgWFRXmkhvkzytKE/K89ZJ0KHRQb5yXDUp voR2WHpN7FSRsN2A5CVwTTMWiwfT6WBL8jBinwyz/rTxHASgOueFewcXGx4qAFbmAnOdLYyaqStVX eOrOibnj4ZZgMZmKGCBmtLO3OFMexn+Y/Y/zw3CQEcLXhEqYfLZG7QoPzGVepceTId7hwe+MEX9nc UoM56VGKW7MkJfj/QF1Re4B9929Koen7JH59uCwCxguzvTa2nLoZ2MJ3oGnmeC/3FXiWxHwhjTdYR JF5iUzBYw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kzMc6-0006sG-Kl; Tue, 12 Jan 2021 16:33:46 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kzMc3-0006ra-0N for linux-arm-kernel@merlin.infradead.org; Tue, 12 Jan 2021 16:33:43 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=mBioehHDUzlvAsPzae77HJfwX+E6M+3CVgwDUqEdzwQ=; b=U3gMFkibCIPYY7WCMckP1Qz2w3 ehyPhKN/2d/DP7Gd5aG2g+3s/ZqAYAeQre+ra5TeoRwPg1ypLFH9UUlsin+PmI5oq5zzqNpejl4MT znWNWxSLdgcSYxRrBG85TkYMEYzlqOvsXl4dDwXla4lI/BwLhKxyMmrkiaSraNgKlbkGJStBPhhz2 NJ3Rts5EJe7yOHQJkn580Y2oqYqO7GisUZGNzMiT0RqkuTve4tCiM5wyq8ysoHa0eX/sdf1t00oQ/ yl38By6JYvCQe/vCKnAbzFQWzhUjpUDUkaOyOW0HLfhZqybTc3Oju99rYpQDzE/zOli9ssgnVbUNB cxs8EabQ==; Received: from hch by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1kzMbT-0052bL-NA; Tue, 12 Jan 2021 16:33:19 +0000 Date: Tue, 12 Jan 2021 16:33:07 +0000 From: Christoph Hellwig To: Robin Murphy Subject: Re: [PATCH v2 0/5] Optimize iommu_map_sg() performance Message-ID: <20210112163307.GA1199965@infradead.org> References: <1610376862-927-1-git-send-email-isaacm@codeaurora.org> <8ad6db90-1d86-db2a-ccb5-dc3f01213289@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <8ad6db90-1d86-db2a-ccb5-dc3f01213289@arm.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html 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: "Isaac J. Manjarres" , pdaly@codeaurora.org, will@kernel.org, joro@8bytes.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, pratikp@codeaurora.org, linux-arm-kernel@lists.infradead.org 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 On Tue, Jan 12, 2021 at 04:00:59PM +0000, Robin Murphy wrote: > Out of curiosity, how much of the difference is attributable to actual > indirect call overhead vs. the additional massive reduction in visits to > arm_smmu_rpm_{get,put} that you fail to mention? There are ways to optimise > indirect calling that would benefit *all* cases, rather than just one > operation for one particular driver. Do we have systems that use different iommu_ops at the same time? If not this would be a prime candidate for static call optimizations. Also I've been pondering adding direct calls to the iommu dma ops like we do for DMA direct. This would allow to stop using dma_ops entirely for arm64. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel