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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBED6C433EF for ; Mon, 25 Oct 2021 15:45:28 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 3228160F70 for ; Mon, 25 Oct 2021 15:45:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3228160F70 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4HdK6G5qpFz2yyK for ; Tue, 26 Oct 2021 02:45:26 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=gxmadbL1; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=arnd@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=gxmadbL1; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4HdK5W5HwNz2xYd for ; Tue, 26 Oct 2021 02:44:47 +1100 (AEDT) Received: by mail.kernel.org (Postfix) with ESMTPSA id 21D9C60F70 for ; Mon, 25 Oct 2021 15:44:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1635176684; bh=t/cG3NYZufoQXI80MvoVKxbOhh2gfbNI54UCGBT3C9s=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=gxmadbL12O9CP1CNjr+LPFEaW4SzKdMH7wBlnUxy2TzbQ9gtUNV7DEu1WSahSAdvL u/BXtC5jblBxPTnpfFqJLIzEtCppyKyls5mNlnSUYhZum9GY/TH9dg/+vSn7xHICbC GLEZE6+WCHun6enc8dfKsjr2kBQWjDquNQv9BmuqxtjICcILdqOVO5TSfQnsQr7pUo 9mokyel9t8DVcl3p+kpJ5J3zE1W6ObHH5vLJl7Mp+ES8XFxHce3uPgJ/Mf77S+X4Hm jYNewKS1aqWHMc6o18eqCgLn8SvSOXBCAmZWVHf49oAPQY46Q6rUNL5PhVtyNchEfn 6muiFFPGVzArQ== Received: by mail-wm1-f46.google.com with SMTP id y22-20020a1c7d16000000b003231ea3d705so13582970wmc.4 for ; Mon, 25 Oct 2021 08:44:44 -0700 (PDT) X-Gm-Message-State: AOAM532wm5KV8vDshX7WAapH2KbbnXX/x7Vlsn8/SnpdX37a/aRhqYU6 POiFPJWQAzD7bzVsB7SitXsVkkX64M7FetFj0Sw= X-Google-Smtp-Source: ABdhPJwVwah/t3YoUqrQSaMsXvLvLT7cunG21zPbQEpZN6hLw+z/xKNabDoDNkoQgi86rA+/qLopU3mOKvl8de4bOgo= X-Received: by 2002:a7b:ce93:: with SMTP id q19mr7749701wmj.98.1635176682689; Mon, 25 Oct 2021 08:44:42 -0700 (PDT) MIME-Version: 1.0 References: <20211022120058.1031690-1-arnd@kernel.org> <2413f412-a390-bbc0-e848-e2a77d1f0ab3@redhat.com> In-Reply-To: <2413f412-a390-bbc0-e848-e2a77d1f0ab3@redhat.com> From: Arnd Bergmann Date: Mon, 25 Oct 2021 17:44:26 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] locking: remove spin_lock_flags() etc To: Waiman Long Content-Type: text/plain; charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-ia64@vger.kernel.org, Peter Zijlstra , "James E.J. Bottomley" , Paul Mackerras , Alexander Gordeev , Will Deacon , Jonas Bonn , linux-s390 , Arnd Bergmann , Helge Deller , Christian Borntraeger , Ingo Molnar , Heiko Carstens , Vasily Gorbik , Boqun Feng , Stefan Kristiansson , Openrisc , Stafford Horne , Parisc List , Linux Kernel Mailing List , linuxppc-dev Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Oct 25, 2021 at 5:28 PM Waiman Long wrote: > On 10/25/21 9:06 AM, Arnd Bergmann wrote: > > > > On s390, we pick between the cmpxchg() based directed-yield when > > running on virtualized CPUs, and a normal qspinlock when running on a > > dedicated CPU. > > I am not aware that s390 is using qspinlocks at all as I don't see > ARCH_USE_QUEUED_SPINLOCKS being set anywhere under arch/s390. I only see > that it uses a cmpxchg based spinlock. Sorry, I should not have said "normal" here. See arch/s390/lib/spinlock.c for their custom queued spinlocks as implemented in arch_spin_lock_queued(). I don't know if that code actually does the same thing as the generic qspinlock, but it seems at least similar. Arnd