From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 009FD3B2A4 for ; Wed, 17 Apr 2024 08:38:13 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1713357493; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aQsJ74gs8uNCq3QmXHX/BCc46rTm4CPPCIlkZTHPEUk=; b=LMqJX3AdMQkkWZq9C0Ki8EjfpAFi6TQ6eTj435Wt7nvYeKLN8SWeUzr8lYb9MPv+s3TGUh FwFuJpkAcORU0fZXOlq2rAVr8Ij/GxsqR1Wf+XLjnym6o0ri0p//nBrpPCv/J5T6IsbDJh bWvQz8jYp3iGFCEkR1Hbe/+OqfAd5ro= Received: from mail-lf1-f70.google.com (mail-lf1-f70.google.com [209.85.167.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-54-3BI8klwANYiJEW6RoZ-wlQ-1; Wed, 17 Apr 2024 08:38:12 -0400 X-MC-Unique: 3BI8klwANYiJEW6RoZ-wlQ-1 Received: by mail-lf1-f70.google.com with SMTP id 2adb3069b0e04-519296de7cfso1502468e87.3 for ; Wed, 17 Apr 2024 05:38:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713357490; x=1713962290; h=content-transfer-encoding:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=aQsJ74gs8uNCq3QmXHX/BCc46rTm4CPPCIlkZTHPEUk=; b=Aa9OLmZctN0HFAtdVYkByR8WVqF65WMfSeb6anKot4w7Pf4yawrTOu1KwSkqW6meHz CWMGa0CL8z28LKGZ24hrpz/C4HVcc4JtC8Z6hRRbhhSLYxJF9fL0RqIpq5f3WVtGCNfI nKG5vlfTGor38qRjS0N23Jr6rcqgql0mYC3uBFEkiuYyuIuXXf5sikyg7rNq33JEvaYy GCHGxrkxuNLjyhcn8aYvzR8SVPlk75hlFoL0/bJ2kIxvw/atldWCwqjSXh3Yis+HadaY IyRZtVD8VDxLyW8DEUW/MOdG4ZbvQjRIFqgX5uGt0S9PJX0GDT67wyx5PbbZhsOuHtxP Nf6A== X-Forwarded-Encrypted: i=1; AJvYcCXpFcNtvKk+Sxc9zPliE/TR5u0QQWWnWile2CErl7x4zgHzZ2hFrte8hxJBFmkOPaU8UP7YA5Wepb3jd7H69bHdauGIWFWSJUV9gw== X-Gm-Message-State: AOJu0Yz16vYqrRtHPAzERAmxHZYfgRXqPbzxBZO/AIZjMJ8M7mI2Ywff Lbq720ZNQKXU+POcz8CXgB6H3ohdJEARKFSaYNYiGltaJsxjfnjjPbIM1EmWOB+mwdPdsYv+CD3 Wm9zgIVJhxzJ1VbauI5rgMdWBukN7Mu09CUGgC3eBFHo1h5EFTAapqy/oGGs= X-Received: by 2002:ac2:47e3:0:b0:518:97dc:d85b with SMTP id b3-20020ac247e3000000b0051897dcd85bmr8375584lfp.63.1713357490571; Wed, 17 Apr 2024 05:38:10 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHeUFJ352/1MTQiEFFy/J/cM1tPdbSfRnd+F7UDGy5i/v8SGgrqD3jBxFhL9k+vsKNJouu3wg== X-Received: by 2002:ac2:47e3:0:b0:518:97dc:d85b with SMTP id b3-20020ac247e3000000b0051897dcd85bmr8375572lfp.63.1713357490294; Wed, 17 Apr 2024 05:38:10 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id e22-20020a170906c01600b00a51cdde5d9bsm8099945ejz.225.2024.04.17.05.38.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Apr 2024 05:38:09 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 221251233A6E; Wed, 17 Apr 2024 14:25:08 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Simon Horman , Eric Dumazet Cc: "David S. Miller" , Jakub Kicinski , Paolo Abeni , Jamal Hadi Salim , Cong Wang , Jiri Pirko , netdev@vger.kernel.org, eric.dumazet@gmail.com, cake@lists.bufferbloat.net In-Reply-To: <20240417083549.GA3846178@kernel.org> References: <20240415132054.3822230-1-edumazet@google.com> <20240415132054.3822230-3-edumazet@google.com> <20240417083549.GA3846178@kernel.org> X-Clacks-Overhead: GNU Terry Pratchett Date: Wed, 17 Apr 2024 14:25:08 +0200 Message-ID: <87cyqouqfv.fsf@toke.dk> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Cake] [PATCH net-next 02/14] net_sched: cake: implement lockless cake_dump() X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Apr 2024 12:38:14 -0000 Simon Horman writes: > + Toke H=C3=B8iland-J=C3=B8rgensen > cake@lists.bufferbloat.net Thanks! > On Mon, Apr 15, 2024 at 01:20:42PM +0000, Eric Dumazet wrote: >> Instead of relying on RTNL, cake_dump() can use READ_ONCE() >> annotations, paired with WRITE_ONCE() ones in cake_change(). >>=20 >> Signed-off-by: Eric Dumazet Just to be sure I understand this correctly: the idea is that with READ/WRITE_ONCE annotations, we can dump the qdisc options without taking the RTNL lock. This means that a dump not be consistent across a concurrent reconfig that changes multiple parameters, but each parameter will be either the new or the old value. Right? -Toke