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Tue, 20 Oct 2026 16:20:37 -0700 (PDT) X-Received: by 2002:a05:6000:2313:b0:48e:d27:bee4 with SMTP id ffacd0b85a97d-48e2642ce22mr436239f8f.2.1792538436673; Tue, 20 Oct 2026 16:20:36 -0700 (PDT) Received: from redhat.com ([2a0d:6fc0:3fd7:5300:3d6b:52a4:a23f:9d0b]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48e2581f0a2sm1544348f8f.10.2026.10.20.16.20.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Oct 2026 16:20:35 -0700 (PDT) Date: Tue, 20 Oct 2026 19:20:31 -0400 From: "Michael S. Tsirkin" To: Willem de Bruijn Cc: linux-kernel@vger.kernel.org, Chris Arges , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Phil Sutter , Jason Wang , Eugenio =?iso-8859-1?Q?P=E9rez?= , Xuan Zhuo , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, virtualization@lists.linux.dev, Max Krasnyansky , Rusty Russell , Jonathan Corbet , Shuah Khan , Randy Dunlap , Simon Horman , linux-doc@vger.kernel.org Subject: Re: [PATCH net v3 6/8] net: add a sysctl to opt out of virtio net hdr checksum validation Message-ID: <20261020191918-mutt-send-email-mst@kernel.org> References: <6f23c55c6eba3e3ec6b2c7e3a80728a326ed58af.1792411304.git.mst@redhat.com> <20261020165610-mutt-send-email-mst@kernel.org> X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: ruwV2hPQoXDGwJvcjDXYYZSq5Ub9n_SqnaHeir4m7LQ_1792538437 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Oct 20, 2026 at 07:13:42PM -0400, Willem de Bruijn wrote: > Michael S. Tsirkin wrote: > > On Tue, Oct 20, 2026 at 03:54:23PM -0400, Willem de Bruijn wrote: > > > > +/* > > > > + * Protects changes to virtio_net_hdr_csum_check_disabled_key and each > > > > + * net->core.sysctl_virtio_net_hdr_csum_check. Readers don't use a lock. > > > > > > it appears that they take the mutex_lock below > > > > Some of them? But > > virtio_net_hdr_csum_check_disabled doesn't, that's the point, right? > > > Yes, but the statement is then too absolute: > _some_ (or most) readers don't use a lock. don't use->don't need?