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[79.34.22.35]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-47a9de1d910sm48486557f8f.6.2026.07.09.02.17.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jul 2026 02:17:58 -0700 (PDT) Date: Thu, 9 Jul 2026 11:17:52 +0200 From: Stefano Garzarella To: "Michael S. Tsirkin" Cc: netdev@vger.kernel.org, Jason Wang , Xuan Zhuo , Eric Dumazet , Eugenio =?utf-8?B?UMOpcmV6?= , Simon Horman , Stefan Hajnoczi , "David S. Miller" , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Paolo Abeni , virtualization@lists.linux.dev, Jakub Kicinski , Jason Wang Subject: Re: [PATCH net v2 2/2] vsock/test: add test for small packets under pressure Message-ID: References: <20260708102904.50732-1-sgarzare@redhat.com> <20260708102904.50732-3-sgarzare@redhat.com> <20260708065853-mutt-send-email-mst@kernel.org> 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; format=flowed Content-Disposition: inline In-Reply-To: <20260708065853-mutt-send-email-mst@kernel.org> On Wed, Jul 08, 2026 at 06:59:41AM -0400, Michael S. Tsirkin wrote: >On Wed, Jul 08, 2026 at 12:29:04PM +0200, Stefano Garzarella wrote: >> From: Stefano Garzarella >> >> Add a test that sends 2 MB of data using randomly sized small packets >> (129-512 bytes) over a SOCK_STREAM connection. Packets above >> GOOD_COPY_LEN (128) bypass the in-place coalescing in recv_enqueue(), >> forcing each one into its own skb. >> >> Without receive queue collapsing, the per-skb overhead eventually >> exceeds buf_alloc and the connection is reset. The test verifies >> that all data arrives and that content integrity is preserved. >> >> Signed-off-by: Stefano Garzarella > >maybe cut down SO_VM_SOCKETS_BUFFER_SIZE? will make it easier to >trigger? Currently, with the default value, the trigger is practically immediate for packets between 129 and 512 bytes, but yes, a smaller buffer size certainly makes this effect even more pronounced. > >anyway > >Acked-by: Michael S. Tsirkin Thanks! If I need to post a v3, I'll add it; otherwise, I guess we can leave it as is or send a follow-up for net-next. Thanks, Stefano