Received: by 2002:a05:6a10:16a7:0:0:0:0 with SMTP id gp39csp644029pxb; Thu, 19 Nov 2020 10:04:58 -0800 (PST) X-Google-Smtp-Source: ABdhPJyUIJwci8d1gTb6vrUunwiURFgn3OLoEcktSZEOkhmoTlCzrRq0eOel5/ByCxC+zEXc4XJS X-Received: by 2002:a50:b761:: with SMTP id g88mr31996019ede.387.1605809097841; Thu, 19 Nov 2020 10:04:57 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1605809097; cv=none; d=google.com; s=arc-20160816; b=RQkEqDkgIH8bEANTd0UVRC6k1z699VnK0hkSGj6efnGSNwh500au0nojQAmE60yTon 6ihnO7NVPcQWALnteUuJA1yy6fO420Fczp25cu6qa2WjxxIGh6Pw6crZvbvQCrxTfv6j tZVuwzy68khjOKTbxx/I3jHjmv4Avizi7vY+YLtxqpYjVChyGIg2azMhZWleDz4u4YiD tggv5Ul8kn1BxWwCuevWhlPUNDY7j8f1vFw7CnBmicQTQCjJnRhKoH3UrKuE962uJI6Q CyQvpoNfysxsdi+h3/sr/csrp+qlmqTxJgEKzpvheFPkWuAZDTH32DqZBF+97HMu3waj P1lQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:dkim-signature; bh=Ma4f4H4dwrdwuSRL3o/wwF+/0TSbqSBTgK3/+Qim5fU=; b=g0jxuRj0dLqMsQcKnfBspms/Otbh8+Oc9G1mIBJ79LySZsrGU4CMpTfNBvy9FyLLWx SqIt6rps3BwBXkGw6nGySbdsNzQ1lfetV/oQrw4CujZ2SOFk2riQu58t/Xaqrj2tsOEh SDiweq4kjexNhaLQG0Im1ZqUKDtyvvwPo54nAHgViEcKIHDLKgX884DjzT+ypuw3s5zu yw1X8eyEhPtf3MNYSZZ04cSUB51H5IA4HjlH4Pd6qWPJHNjuj9W8KxNLsYk9nOPtHsam Dq+stOfH0IwwoLoHV4bGFbIhaPxJIFyZx3H4rJbhYo5Pse5AFENi2r4xpSAqqjN5hSKC ORIQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=KSvuCQGM; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id v9si289025edb.48.2020.11.19.10.04.24; Thu, 19 Nov 2020 10:04:57 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=KSvuCQGM; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729534AbgKSSCS (ORCPT + 99 others); Thu, 19 Nov 2020 13:02:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728609AbgKSSCR (ORCPT ); Thu, 19 Nov 2020 13:02:17 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B210C0613D4 for ; Thu, 19 Nov 2020 10:02:17 -0800 (PST) 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=Ma4f4H4dwrdwuSRL3o/wwF+/0TSbqSBTgK3/+Qim5fU=; b=KSvuCQGM/XHs7Bng0bqSoG/dt6 wxprvYnyDSPXdh2bCrY1y5SSQoA0G/UZR5tM547DtsK92VwttTY2LY+BBhr4KR4AWuYeOuDnxltmw PJrilCYpggLAWqTDirQVYHRac/CnEIy8HVLUG2wb9ALNzdTaewpNxHmh8oKjzhP+JQXnPxPJdt2K7 bUh3x/ERXfZMkqOQEm8bXYjvHbnGGTb1iQOnsqFVoqDWC70GNZ021F8enYaKL7Z49THoGgmnOmfeq AXZ8Dx+jFQbeJ12p5VjuNYewVt+saELHRAlNUNvjtaPWxhr1d5Fqcw0ri/sgYG+O4ojLfC+TWizYI au35HJgg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kfoFy-0006MP-74; Thu, 19 Nov 2020 18:02:06 +0000 Date: Thu, 19 Nov 2020 18:02:06 +0000 From: Christoph Hellwig To: Andrea Arcangeli Cc: Thomas Gleixner , Ingo Molnar , Andi Kleen , Rafael Aquini , Waiman Long , linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/1] x86: restore the write back cache of reserved RAM in iounmap() Message-ID: <20201119180206.GA24054@infradead.org> References: <20201119175902.17394-1-aarcange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201119175902.17394-1-aarcange@redhat.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 19, 2020 at 12:59:01PM -0500, Andrea Arcangeli wrote: > Hello everyone, > > We identified some PCD set on the direct mapping causing hardly > reproducible performance issues and this patch fixes the ultimate root > cause. > > The caller for now has been tweaked to avoid triggering this case (now > that we know about it) What is the callers? The whole SetPageReservered + ioremap* thing you mention in the actual patch is completely bogus. I think we'll need to reject that as well and fix the caller.