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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 5749CC43381 for ; Fri, 22 Feb 2019 19:56:37 +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 1302020700 for ; Fri, 22 Feb 2019 19:56:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="UmqmjW64"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=amazonses.com header.i=@amazonses.com header.b="ACpqIAik" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1302020700 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=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:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: MIME-Version:References:Message-ID:In-Reply-To:Subject:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+m1zv+WNiOGzpKTwMFJ7Rxy83q+bFzem2hs18RUONx0=; b=UmqmjW643szD+0WG1n/5dhlwJ HPyIQM2+nfEcDEoAcLB/ParZ6SesLUSzRxDZJ+xWn5hBJQfz2hyO2DXtO8WIBnrBjBVOVUANP5E01 Lkxq/X2x1bzopEUY6jcYZCDzqtDjHjLbYwQ/GA8lL3U9mcxdJar2TXLNdR8aWV6dW6XNcPE3kz48y 6SLisUHWxU/FBtqN4lnrU48BXWQ9gw6OlR+i4pdk4N2vRpxqt7co6/YCZJSTcQQNtZv2lkj592F8D c7CJ7BoN11xk/U6djNfjMufp2vEuetrwkkfxVaxnjq1tUfTgGCaYwnkUs88RvvTgNm1wRVGanV3J5 ZL4rsRhFw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gxGvy-0006av-9g; Fri, 22 Feb 2019 19:56:34 +0000 Received: from a9-32.smtp-out.amazonses.com ([54.240.9.32]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gxGvv-0006aV-6G for linux-riscv@lists.infradead.org; Fri, 22 Feb 2019 19:56:32 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=ug7nbtf4gccmlpwj322ax3p6ow6yfsug; d=amazonses.com; t=1550865387; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:MIME-Version:Content-Type:Feedback-ID; bh=yOwBC67SnQnf5LadpmjG8imXAUii78tucrw54nZjg7Y=; b=ACpqIAik0BxToHoRFFbJGxOTHrSQZanh9RXR3hGDVUCtUkOvZ+m4bUptxXQzLWlM u41YCt35hYyAiaDzrmoRnOXredmSwim6uq0CuYWriiMUI9WO2ZCpwW1Iv1lSw2EOREr i1hFV8MFoao5zLmiw5sXG2ZbrQQKWL2+PA1Cycn4= Date: Fri, 22 Feb 2019 19:56:27 +0000 From: Christopher Lameter X-X-Sender: cl@nuc-kabylake To: =?ISO-8859-15?Q?Bj=F6rn_T=F6pel?= Subject: Re: per-cpu thoughts In-Reply-To: Message-ID: <0100016916c7cda0-9622bc7c-b8db-4967-83e6-43692aa58ec8-000000@email.amazonses.com> References: <0100016915bc54e5-22f89b41-21e8-4133-9550-e85f4223ea32-000000@email.amazonses.com> <2acd8a4393d4e9c526bcfa4aca63e4cf@mailhost.ics.forth.gr> <0100016915ec5184-5c0a50db-1b61-428f-ae2c-d23ce8d465d5-000000@email.amazonses.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-1869833838-1550865385=:30554" X-SES-Outgoing: 2019.02.22-54.240.9.32 Feedback-ID: 1.us-east-1.fQZZZ0Xtj2+TD7V5apTT/NrT6QKuPgzCT/IC7XYgDKI=:AmazonSES X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190222_115631_341963_8958CA36 X-CRM114-Status: UNSURE ( 6.75 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Nick Kossifidis , Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-1869833838-1550865385=:30554 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT On Fri, 22 Feb 2019, Björn Töpel wrote: > > The problem is that the register needs to be referenced by the amo > > instruction. Can amoadd increment an address relative to a scratch > > register? > > > > It cannot. So, we'll end up with (at least) a preempt disabled region... If we need to do that then we already have so much overhead due to that processing that it may not be worthwhile. lc/sc overhead is minor compared to switching preempt on and off I think. --8323329-1869833838-1550865385=:30554 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv --8323329-1869833838-1550865385=:30554--