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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 092A5C433DB for ; Mon, 29 Mar 2021 19:12:04 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 9D5766196E for ; Mon, 29 Mar 2021 19:12:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D5766196E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+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=desiato.20200630; 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=ZOHefo8nC62ocln0/ZqE2jOX89HyhTlnRgKwoD+kV4U=; b=RHdDTWYzcu7DuGosi0kA07K8O F+NfvC+a0s4YVuDSsoXe+6O4LOujQFsayE0BaiEyCPGutaVrd5zPP0K5ld2DyfeTRliOZJK5ug/ol GQB2omzuSTxskS1hBCCms6FA7ZBFMKmZEq00lNF32RxtGcrp26CEk+r0rXXSRXct2BOh7qEZC3RLx uKVq95CaJ5F6NwDusf7gXLfxNp6FXK5gFN1GHza7wiCZ7vHLBsVv9CoEgK5r/rg5jQo7dbk05VKaa 4kREthU1L3/jD4OymHn4ihcTYGdIVIUWRSdPeeCPykXapKV+cX+cFk5c/RqmV9qDcaGFuLkBX5VV+ KckIwfxFg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lQxIW-001BxL-53; Mon, 29 Mar 2021 19:11:36 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lQq6L-000cOh-10 for linux-riscv@desiato.infradead.org; Mon, 29 Mar 2021 11:30:33 +0000 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=xAASgCT1znE4iZyX4yKtFW+FR4NtFv4F0rZP0TttRpc=; b=IUiKLtt370+VXpr4Dpb9tIRnmD lUlt8V0bVGbfLA+R8YSPIs2KN/WpHeEsLTx1xJLbLiXLynAZmIxYNh4kuFIPd1cjaXGTgOSWQoOIV QETpqcvhbwpVKGfbKrnWvzkGFspWw6FRMud3euBEeDrqOAmp45mWd2u7Kvf3O9M4aI5VFhAcu8//F AOGsqL6Ut9BtLNCe6g8wHoyGxVKxBkiRTrveBGZbdnHRjwFwVYBvF/DfhKrlZ9HZXRFFvwsnKDWWN e5CnjI2RJ1h+QIvFIOvGX8kRLrM3d7ZO9E4RhkJ9yNOU24aaT28io+SH1vNMaNB0s+x2RrCPd/ZBl 5izOhRpA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lQq5j-001TUs-4F; Mon, 29 Mar 2021 11:30:08 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 982223069B1; Mon, 29 Mar 2021 13:29:54 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 85F90207539C8; Mon, 29 Mar 2021 13:29:54 +0200 (CEST) Date: Mon, 29 Mar 2021 13:29:54 +0200 From: Peter Zijlstra To: Arnd Bergmann Cc: Guo Ren , linux-riscv , Linux Kernel Mailing List , linux-csky@vger.kernel.org, linux-arch , Guo Ren , Will Deacon , Ingo Molnar , Waiman Long , Anup Patel , Sebastian Andrzej Siewior Subject: Re: [PATCH v4 3/4] locking/qspinlock: Add ARCH_USE_QUEUED_SPINLOCKS_XCHG32 Message-ID: References: <1616868399-82848-1-git-send-email-guoren@kernel.org> <1616868399-82848-4-git-send-email-guoren@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-BeenThere: linux-riscv@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-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Mon, Mar 29, 2021 at 01:16:53PM +0200, Peter Zijlstra wrote: > Anyway, an additional 'funny' is that I suspect you cannot prove fwd > progress of the entire primitive with any of this on. But who cares > about details anyway.. :/ What's the architectural guarantee on LL/SC progress for RISC-V ? And what if you double loop it like cmpxchg() ? _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv