Received: by 2002:ab2:6a05:0:b0:1f8:1780:a4ed with SMTP id w5csp492773lqo; Fri, 10 May 2024 06:20:40 -0700 (PDT) X-Forwarded-Encrypted: i=2; AJvYcCVJMR2nHnOEz6Abiir0cw9mweStqMIs5c3599+NZKy00b0hsTzxnnX1fqXs4OZ3cG7yiARaKBu5HTHbYvOwGecyKaGgcWMYPqzra2pQag== X-Google-Smtp-Source: AGHT+IEM3U5O8ZOpjJe8QrOTqIhBwc1PtSZj6CtRW4SIs3Rs7GpYDQKwsdI59F7iNnIAuKPGrbvm X-Received: by 2002:a17:906:2bc4:b0:a59:ac10:9be5 with SMTP id a640c23a62f3a-a5a2d292b1dmr249290466b.27.1715347239847; Fri, 10 May 2024 06:20:39 -0700 (PDT) Return-Path: Received: from am.mirrors.kernel.org (am.mirrors.kernel.org. [2604:1380:4601:e00::3]) by mx.google.com with ESMTPS id a640c23a62f3a-a5a17c2cc57si207118066b.995.2024.05.10.06.20.39 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 May 2024 06:20:39 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel+bounces-175817-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@redhat.com header.s=mimecast20190719 header.b=EHC9ZEbP; arc=fail (body hash mismatch); spf=pass (google.com: domain of linux-kernel+bounces-175817-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) smtp.mailfrom="linux-kernel+bounces-175817-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by am.mirrors.kernel.org (Postfix) with ESMTPS id 922841F26AC6 for ; Fri, 10 May 2024 13:20:39 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3DE3012C461; Fri, 10 May 2024 13:20:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EHC9ZEbP" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E63043F8D1 for ; Fri, 10 May 2024 13:20:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715347232; cv=none; b=GgK0r6Tnbaq47WyH1z8LTC37sEZak/lwZC5XwF/+5vHwiX4qA9BePKkvMN+prYdxjOPTm1pfgYqvpEWMbC+McTpC4mM+3wUBY3zceM7XwSQmXwJq0vMWkZ7jVzw+0FHRE6eJRvja22ldVrODFv3bh3aOGZS8kt+iXvkU7km3hxo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715347232; c=relaxed/simple; bh=3Tl2B5EkwGEZNx5cMVsNSYK6mjudFoYF8s7Ug0qESew=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dJhO7G9yiOzH4eYxtS3JrO6Tg4IQRQM++QzeMfAh+6f1YSSuBRhRDR0vMjqm0o1oIf/Imxp+BttC3j96bnj6mh1jkMU1oYggx4cnCL4JtF1DPh/Zg7xUnumCGUzq8BiTvYeYgEtYqeOop825B2lINhDhhRKYMXpIAGr5RGNfK6Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=EHC9ZEbP; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1715347229; 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: in-reply-to:in-reply-to:references:references; bh=3Tl2B5EkwGEZNx5cMVsNSYK6mjudFoYF8s7Ug0qESew=; b=EHC9ZEbPmV0HU6F81vXBB1TdL7PIjM9qhmSD+acW00+ykCirToNOujKr3EE9lmgoOycaIL 436qHwsOUFBpj927F2626tP6jl8R1eZbRj8frqf+2c4LgZeGqLLcmoaBIALpFCTe5cEbrs YdkgHZrsDymERWEZmVaadSTvIgChvCA= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-529-1IN8NqBBOEqJ0JjcE-RsZg-1; Fri, 10 May 2024 09:20:19 -0400 X-MC-Unique: 1IN8NqBBOEqJ0JjcE-RsZg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C795929AC039; Fri, 10 May 2024 13:20:18 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.196]) by smtp.corp.redhat.com (Postfix) with SMTP id E61E6DDC97A; Fri, 10 May 2024 13:20:15 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 10 May 2024 15:18:53 +0200 (CEST) Date: Fri, 10 May 2024 15:18:50 +0200 From: Oleg Nesterov To: "Paul E. McKenney" Cc: "Uladzislau Rezki (Sony)" , RCU , Neeraj upadhyay , Boqun Feng , Hillf Danton , Joel Fernandes , LKML , Oleksiy Avramchenko , Frederic Weisbecker , Peter Zijlstra Subject: Re: [PATCH 25/48] rcu: Mark writes to rcu_sync ->gp_count field Message-ID: <20240510131849.GB24764@redhat.com> References: <20240507093530.3043-1-urezki@gmail.com> <20240507093530.3043-26-urezki@gmail.com> <4c9e89b5-c981-4809-8bc2-247563ce04e9@paulmck-laptop> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4c9e89b5-c981-4809-8bc2-247563ce04e9@paulmck-laptop> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 On 05/07, Paul E. McKenney wrote: > > By the stricter data-race rules used in RCU code [1], .. > [1] https://docs.google.com/document/d/1FwZaXSg3A55ivVoWffA9iMuhJ3_Gmj_E494dLYjjyLQ/edit?usp=sharing I am getting more and more confused... Does this mean that KCSAN/etc treats the files in kernel/rcu/ differently than the "Rest of Kernel"? Or what? And how is it enforced? Oleg.