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=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 2C257C4338F for ; Wed, 11 Aug 2021 10:10:56 +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 D1C5960D07 for ; Wed, 11 Aug 2021 10:10:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D1C5960D07 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org 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:MIME-Version:References: 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=R4gOHsyWM4ShEAZskbubI93fR9JjmCXYXKYNgW1OhO4=; b=TyKomJ/O5pwvr9 WL7WEtFk4m4CMFH+sbQA0joiQ0InNyIPg82Zk/KJ9LfV3zFespzDfgD5Y42kTdH16B9m+Z0/0pQKD RDh4k/Ioi09K+ltm4g8nZRSAMDvK4RlyVGo1GjKy8obTfta6o5vtozp82RAsQpJwpYewFH3yKqnJs 1asmcxSyfIQUnxntLtjrI6VTmSa8RtiKYyKndMB9lJKqi01CrmHsd/4WzRntT+Q8V5/4eSqM3ytqh HpX0WhRQdCzNj1WQxC75IjsGTgGdRfQuJoK0buFbRBwzvgwTJRni4pJ/r5o3Z6Bj+iRPN1X9n/omc pcBFWNq7Em+WOqepzWIQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDlAm-006YDA-5U; Wed, 11 Aug 2021 10:09:20 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDlAc-006YBe-N9 for linux-arm-kernel@lists.infradead.org; Wed, 11 Aug 2021 10:09:12 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 20E5A601FD; Wed, 11 Aug 2021 10:09:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628676550; bh=WFdcMDOdwT6iqhf90eKghlHbPA/yHhanICAd1+UlmRM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vAuQbY91bb67oIRwclNTdMUX+7hGHLmfOVBobsNUxT24P57KeqHCdpi20UnTatwot OZTwRCmKEHFSunGGfYDgTE4fvaSJFZSFMq9eR4Vj+Mq7MkOs0tQGNsscLUOj5Vs3LI fi6VUbSxohmzU3VdJiV4LVrxqFwDx+djRZUBmkqB5Nw8ogI/nwRutVaqUWWic9Q+DV XcXffrF9Gzgc7UVsNls69LOLZ/rgVhMuQEvqM7u6l6pJI6unO60/779Am1YIu7Ah+7 oxEOBtNDLKDCD61Gii2bw60MtIHfAyuFvv9rv9XqZRGmgsDTvTYd77MPiKiw1TLOow H1fZODrUX+eyg== Date: Wed, 11 Aug 2021 11:09:06 +0100 From: Will Deacon To: "Leizhen (ThunderTown)" Cc: Robin Murphy , Joerg Roedel , linux-arm-kernel , iommu , linux-kernel Subject: Re: [PATCH RFC 2/8] iommu/arm-smmu-v3: Add and use static helper function arm_smmu_cmdq_issue_cmd_with_sync() Message-ID: <20210811100905.GB4426@willie-the-truck> References: <20210626110130.2416-1-thunder.leizhen@huawei.com> <20210626110130.2416-3-thunder.leizhen@huawei.com> <20210810182454.GB3296@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210811_030910_820519_B1F54AA2 X-CRM114-Status: GOOD ( 24.54 ) 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 On Wed, Aug 11, 2021 at 10:16:39AM +0800, Leizhen (ThunderTown) wrote: > > > On 2021/8/11 2:24, Will Deacon wrote: > > On Sat, Jun 26, 2021 at 07:01:24PM +0800, Zhen Lei wrote: > >> The obvious key to the performance optimization of commit 587e6c10a7ce > >> ("iommu/arm-smmu-v3: Reduce contention during command-queue insertion") is > >> to allow multiple cores to insert commands in parallel after a brief mutex > >> contention. > >> > >> Obviously, inserting as many commands at a time as possible can reduce the > >> number of times the mutex contention participates, thereby improving the > >> overall performance. At least it reduces the number of calls to function > >> arm_smmu_cmdq_issue_cmdlist(). > >> > >> Therefore, function arm_smmu_cmdq_issue_cmd_with_sync() is added to insert > >> the 'cmd+sync' commands at a time. > >> > >> Signed-off-by: Zhen Lei > >> --- > >> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 33 +++++++++++++-------- > >> 1 file changed, 21 insertions(+), 12 deletions(-) > >> > >> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > >> index 2433d3c29b49ff2..a5361153ca1d6a4 100644 > >> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > >> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > >> @@ -858,11 +858,25 @@ static int arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, > >> return arm_smmu_cmdq_issue_cmdlist(smmu, cmd, 1, false); > >> } > >> > >> -static int arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu) > >> +static int __maybe_unused arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu) > >> { > >> return arm_smmu_cmdq_issue_cmdlist(smmu, NULL, 0, true); > >> } > >> > >> +static int arm_smmu_cmdq_issue_cmd_with_sync(struct arm_smmu_device *smmu, > >> + struct arm_smmu_cmdq_ent *ent) > >> +{ > >> + u64 cmd[CMDQ_ENT_DWORDS]; > >> + > >> + if (arm_smmu_cmdq_build_cmd(cmd, ent)) { > >> + dev_warn(smmu->dev, "ignoring unknown CMDQ opcode 0x%x\n", > >> + ent->opcode); > >> + return -EINVAL; > >> + } > >> + > >> + return arm_smmu_cmdq_issue_cmdlist(smmu, cmd, 1, true); > >> +} > > > > This function is almost identical to arm_smmu_cmdq_issue_cmd(). How about > > moving the guts out into a helper: > > > > static int __arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, > > struct arm_smmu_cmdq_ent *ent, > > bool sync); > > > > and then having arm_smmu_cmdq_issue_cmd_with_sync() and > > arm_smmu_cmdq_issue_cmd() wrap that? > > OK, I will do it. > > How about remove arm_smmu_cmdq_issue_sync()? It's unused now. Sure. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel