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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 5E839C10DCE for ; Sun, 15 Mar 2020 18:32:39 +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 196F8206BE for ; Sun, 15 Mar 2020 18:32:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="UXDbWT5C" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 196F8206BE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.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=6Bm38f0cIQguZfDnBSVGBhXv8aB7Vkb2jErC9x8SX84=; b=UXDbWT5CBw0LzZ sPujfSEh2JK6vyAqrUNQsngkxARcuY8U5jRZipTjAxGZyPkkrAxblmzqpKqUxbBLBQkUeB3cS+vyG ILvPQ15/ck/UJ+ajq+8SuCSrlY83l5ZBSox70WuSADrlBU+pmbNFTu2KlkITa5euavx07wi1bI0Uz PZLNJe/Mi8b3MhEtgFa2fAjbY3m9vMBbp5jU27t27N44h4nrhIM+UHAQTI6ojt4GR2tJ3qB/eoFCx ixaMJGsASvah/VtBMWk9yWMXR5bDECoiY8KzjplRizD2Xd1v5w9Z6L1rjKsYVa59dZcgs86Auf6/E leG/S/1yG3rXttzAS/rg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jDY3u-0004iM-91; Sun, 15 Mar 2020 18:32:34 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jDY3q-0004i2-Ly for linux-arm-kernel@lists.infradead.org; Sun, 15 Mar 2020 18:32:32 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E967D1FB; Sun, 15 Mar 2020 11:32:29 -0700 (PDT) Received: from mbp (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BEC763F67D; Sun, 15 Mar 2020 11:32:26 -0700 (PDT) Date: Sun, 15 Mar 2020 18:32:16 +0000 From: Catalin Marinas To: Vincenzo Frascino Subject: Re: [PATCH v3 21/26] arm64: Introduce asm/vdso/arch_timer.h Message-ID: <20200315183151.GE32205@mbp> References: <20200313154345.56760-1-vincenzo.frascino@arm.com> <20200313154345.56760-22-vincenzo.frascino@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200313154345.56760-22-vincenzo.frascino@arm.com> 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-20200315_113230_756479_B81F16BC X-CRM114-Status: GOOD ( 12.69 ) 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: Mark Rutland , Dmitry Safonov <0x7f454c46@gmail.com>, linux-mips@vger.kernel.org, Will Deacon , linux-arch@vger.kernel.org, Marc Zyngier , x86@kernel.org, Russell King , clang-built-linux@googlegroups.com, Ingo Molnar , Kees Cook , Arnd Bergmann , Will Deacon , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , Peter Collingbourne , linux-arm-kernel@lists.infradead.org, Andrei Vagin , Stephen Boyd , Nick Desaulniers , linux-kernel@vger.kernel.org, Mark Salyzyn , Paul Burton Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Mar 13, 2020 at 03:43:40PM +0000, Vincenzo Frascino wrote: > The vDSO library should only include the necessary headers required for > a userspace library (UAPI and a minimal set of kernel headers). To make > this possible it is necessary to isolate from the kernel headers the > common parts that are strictly necessary to build the library. > > Introduce asm/vdso/arch_timer.h to contain all the arm64 specific > code. This allows to replace the second isb() in __arch_get_hw_counter() > with a fake dependent stack read of the counter which improves the vdso > library peformances of ~4.5%. Below the results of vdsotest [1] ran for > 100 iterations. The subject seems to imply a non-functional change but as you read, it gets a lot more complicated. Could you keep the functional change separate from the header clean-up, maybe submit it as an independent patch? And it shouldn't go in without Will's ack ;). -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel