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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E828FEB64D7 for ; Tue, 20 Jun 2023 08:48:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230088AbjFTIsK (ORCPT ); Tue, 20 Jun 2023 04:48:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229976AbjFTIsH (ORCPT ); Tue, 20 Jun 2023 04:48:07 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C97C2C2 for ; Tue, 20 Jun 2023 01:48:04 -0700 (PDT) Received: from mail.alien8.de (mail.alien8.de [IPv6:2a01:4f9:3051:3f93::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 9D8C91EC0501; Tue, 20 Jun 2023 10:48:02 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1687250882; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=Hlqv2LjqdROM+DT2kM0Js7XAxGDJkCC+FDB9YEGz2M8=; b=YLeRxOSD0RF6GgVFp1ndc+nnD0QVHB/DETWCs4sz2X0tmKRCfXef39GRqKP+t2BWEoagOc uS6uCAJZC9q9WqDk/x9t0SlNtNL/d9sqYPjzETuCfCt2cRNczXN3enqzk8SCQ1Rdby45wW 9rz7rmjgIya86aXr/EtUhyk1sBeC7LY= X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id T7VLpobmf2_L; Tue, 20 Jun 2023 08:48:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1687250880; bh=Hlqv2LjqdROM+DT2kM0Js7XAxGDJkCC+FDB9YEGz2M8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BpVlB2PlPQ6vw7Z19+vlYjtmyjvR+Lphhotdz3C6mVWeVY9NySRcNupwMclNDgzro t8c+mOXeMyjmdZyECQ3qZDQ9IDUaowetwFwOkoB4+Zv2YC+gkSe3OU+lGJqv5m/XkN vrwuFNyhQDLDKxQ0uvzLjSZZCg96Zxx92gA4Rg45Z3NBIBweOMZzBxK44mE543mgyY nyyaFztQ/iW0ZdLWq5l+lQHHoeMDLUpF52x+4MK6WWD1shi2d6c2uq8+a00GKbBXa9 nOaXqxe+esAGhFRCps+zD6xJC8Uglajf+abO0HuPlx5nmv7Kc8yI2iCV7LzDqPMJSh MWfZwqj3jCV/eHnwrs+MGcJJl8APPrY314mvWj2V66wU7O1rKwOuj5gDHA2UGJ2f52 9hmXVtoPs/U8ILMP4UjnoZY6tPJ+aIuQ7ktw0gvvO7Rnqn/yhZI7d/B9tN1pSbWwD+ rdlSygi0TxNV08nswZR7szV4Xo+upBv8B4efxMPm9HU24htSnclGFIfZ68iLSUQAmK nNptW3Eg1KtvCsDWfSZDs5U7CpnY0Z9l2hk3BqE9yI0auCIkVKfStdZbb7D5X2nfFk OeWVHihEOZfpHvNYF6MJ/vQFAhatnGfM/qHzpnUgz5ysWXUjCJkOZHB5I9QKR0htPy naUx2CBjksNDxaOprhKodkTE= Received: from zn.tnic (p200300Ea971Dc5b2329c23FfFea6A903.dip0.t-ipconnect.de [IPv6:2003:ea:971d:c5b2:329c:23ff:fea6:a903]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 2BE5A40E0034; Tue, 20 Jun 2023 08:47:50 +0000 (UTC) Date: Tue, 20 Jun 2023 10:47:44 +0200 From: Borislav Petkov To: Thomas Gleixner Cc: LKML , x86@kernel.org, Mario Limonciello , Tom Lendacky , Tony Battersby , Ashok Raj , Tony Luck , Arjan van de Veen , Eric Biederman Subject: Re: [patch v3 3/7] x86/smp: Remove pointless wmb()s from native_stop_other_cpus() Message-ID: <20230620084744.GUZJFnsClkvsGQmnRs@fat_crate.local> References: <20230615190036.898273129@linutronix.de> <20230615193330.378358382@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230615193330.378358382@linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 15, 2023 at 10:33:54PM +0200, Thomas Gleixner wrote: > The wmb()s before sending the IPIs are not synchronizing anything. > > If at all then the apic IPI functions have to provide or act as appropriate > barriers. > > Remove these cargo cult barriers which have no explanation of what they are > synchronizing. > > Signed-off-by: Thomas Gleixner > --- > V3: Remove second instance and reword changelog - PeterZ > --- > arch/x86/kernel/smp.c | 6 ------ > 1 file changed, 6 deletions(-) Reviewed-by: Borislav Petkov (AMD) -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette