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 C077AC7EE29 for ; Thu, 25 May 2023 17:09:08 +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: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=aWjYe+ikXKxuF4t16kA05aPxS7zQP1/4rtBhnXQGiww=; b=qgsI2R1R+sLUIJ SVA7UeQr8jgspLGhyeiuRzfPH5pU4LuKYQPsAjxsD8blfgcAliZSU8sZBuyO3YtEEDjy7nk/rhKxE T3+5t7BxR7m+dvj0ukDCswQxjIIBYexyp8NgrmNvqVew/D33QgfbuG81pYFHNuxXGeuYiJ8P4RBYl u5+zCa3eefJoxTKWZtUORpxpwSqiMvaswWC8IK/sFtP88sdMeGN47xKE4ZCyHbAFysU07V+dBq2xd WihagNwjsQs1B0he33Kp0DJO+PkNysKBCduPW39Zyx/gHWdFQPT93JDwfRD+H+Dnpfe1WvSrK7M5T MIAKDRFTRkjNT0kh0BQg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q2ES6-00HBHg-2O; Thu, 25 May 2023 17:08:38 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1q2ES3-00HBGn-0L for linux-arm-kernel@lists.infradead.org; Thu, 25 May 2023 17:08:36 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AA0EE61A25; Thu, 25 May 2023 17:08:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCE86C433D2; Thu, 25 May 2023 17:08:30 +0000 (UTC) Date: Thu, 25 May 2023 18:08:27 +0100 From: Catalin Marinas To: Robin Murphy Cc: Linus Torvalds , Christoph Hellwig , Arnd Bergmann , Greg Kroah-Hartman , Will Deacon , Marc Zyngier , Andrew Morton , Herbert Xu , Ard Biesheuvel , Isaac Manjarres , Saravana Kannan , Alasdair Kergon , Daniel Vetter , Joerg Roedel , Mark Brown , Mike Snitzer , "Rafael J. Wysocki" , linux-mm@kvack.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v5 15/15] arm64: Enable ARCH_WANT_KMALLOC_DMA_BOUNCE for arm64 Message-ID: References: <20230524171904.3967031-1-catalin.marinas@arm.com> <20230524171904.3967031-16-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230525_100835_177543_63AAFFB7 X-CRM114-Status: GOOD ( 25.90 ) 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 Thu, May 25, 2023 at 05:12:37PM +0100, Robin Murphy wrote: > On 24/05/2023 6:19 pm, Catalin Marinas wrote: > > With the DMA bouncing of unaligned kmalloc() buffers now in place, > > enable it for arm64 to allow the kmalloc-{8,16,32,48,96} caches. In > > addition, always create the swiotlb buffer even when the end of RAM is > > within the 32-bit physical address range (the swiotlb buffer can still > > be disabled on the kernel command line). > > > > Signed-off-by: Catalin Marinas > > Cc: Will Deacon > > --- > > arch/arm64/Kconfig | 1 + > > arch/arm64/mm/init.c | 7 ++++++- > > 2 files changed, 7 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > index b1201d25a8a4..af42871431c0 100644 > > --- a/arch/arm64/Kconfig > > +++ b/arch/arm64/Kconfig > > @@ -120,6 +120,7 @@ config ARM64 > > select CRC32 > > select DCACHE_WORD_ACCESS > > select DYNAMIC_FTRACE if FUNCTION_TRACER > > + select DMA_BOUNCE_UNALIGNED_KMALLOC > > We may want to give the embedded folks an easier way of turning this off, > since IIRC one of the reasons for the existing automatic behaviour was > people not wanting to have to depend on the command line. Things with 256MB > or so of RAM seem unlikely to get enough memory efficiency back from the > smaller kmem caches to pay off the SWIOTLB allocation :) I thought about this initially and that's why I had two options (ARCH_WANT_* and this one). But we already select SWIOTLB on arm64, so for the embedded folk the only option is swiotlb=noforce on the cmdline which, in turn, limits the kmalloc caches to kmalloc-64 (or whatever the cache line size is) irrespective of this new select. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel