From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 E02A06131 for ; Wed, 6 Sep 2023 22:32:20 +0000 (UTC) Received: from mail-qk1-x735.google.com (mail-qk1-x735.google.com [IPv6:2607:f8b0:4864:20::735]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4A9619B6 for ; Wed, 6 Sep 2023 15:32:19 -0700 (PDT) Received: by mail-qk1-x735.google.com with SMTP id af79cd13be357-76f0807acb6so21205085a.1 for ; Wed, 06 Sep 2023 15:32:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1694039539; x=1694644339; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=7pwTqtbc0SRtCc8sodvt2GgE2trx1vmLPyIifmTblUg=; b=P3AUlqh205Sms2ju7VThmoqyetbAqhKAPAngIJ/78CtZwNSEJi14dj/0liTPmlC881 yaz/L6rnKvAX5Awpw51iRz6UEXO+UN1w9aqqyepCGPrirnn4rtt4fxDiBVk0Vu8QAubt gdlkCR8YQ7GHhLYGPNTVW52cZxUrwPIN793OUZ4ewnMhGWSV8CjVKk0TKYr3GH9/d5Xx LVDKidPkKfoN8YvSl8BDEYLBxJVuPhUDPOQZ/RAZeCDIApXjFqQRHkAFz+u4oX8tolNH m7YmEI/OekYGE53YHcfxP6mHEVS5GqqBo9mImbQ/hiKeHU9n2mL4sLr/qZv5ipJ0dqNf Q6Pw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1694039539; x=1694644339; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=7pwTqtbc0SRtCc8sodvt2GgE2trx1vmLPyIifmTblUg=; b=FJqJb5NKjhAR0dvRrxTRyOU7gDUewpujeh4UUk/0YcTC5VSFU7jjkr7yOTENiWHMHj nSq2HQDM56ke6PHK1fqNeH+twUSGZqOo08DnDVGBeixFA8qdUKZp65NtjAy2+hRB2gzY lNt5go/l/HkwEwKR5M2XjXQXoVh0JcZcGLOID/TYF+F8FUds1SFL42wNyvLPBny7chRI omK4j6czuUXQV85fkJt1taQQkQUCvB9Vs1L+OougOinmOXd9amwC6RTzjzn59cS9rdpy W7ZFVfEI4kU99FTZZw2WRO0DaaqhSD+ary3BU9jQR6wEppBWW5GtymBl8CDQGIC6XZCF YWTA== X-Gm-Message-State: AOJu0YzgbtJ6QO/lOrmwDbrdZ2W71Rj5NAE1du0bFepJfmHJGh/zuTqS mI8PEBd4ivEuWCB4ElOytOU= X-Google-Smtp-Source: AGHT+IHZ/rZ98Rcpybhw3OJHzPptwRjMxQK3iwyJ+KWF3eO4yNMjyL8h2G/FcjAS+rjqFIZY4XlDSA== X-Received: by 2002:a05:620a:3954:b0:770:96a1:5580 with SMTP id qs20-20020a05620a395400b0077096a15580mr2163717qkn.14.1694039538733; Wed, 06 Sep 2023 15:32:18 -0700 (PDT) Received: from localhost (modemcable065.128-200-24.mc.videotron.ca. [24.200.128.65]) by smtp.gmail.com with ESMTPSA id y2-20020a37e302000000b0076effd9809fsm5273004qki.110.2023.09.06.15.32.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Sep 2023 15:32:18 -0700 (PDT) Date: Wed, 6 Sep 2023 18:32:17 -0400 From: Benjamin Poirier To: Liang Chen Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org Subject: Re: [RFC PATCH net-next] pktgen: Introducing a parameter for non-shared skb testing Message-ID: References: <20230906103508.6789-1-liangchen.linux@gmail.com> Precedence: bulk X-Mailing-List: netdev@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: <20230906103508.6789-1-liangchen.linux@gmail.com> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On 2023-09-06 18:35 +0800, Liang Chen wrote: > Currently, skbs generated by pktgen always have their reference count > incremented before transmission, leading to two issues: > 1. Only the code paths for shared skbs can be tested. > 2. Skbs can only be released by pktgen. > To enhance testing comprehensiveness, introducing the "skb_single_user" > parameter, which allows skbs with a reference count of 1 to be > transmitted. So we can test non-shared skbs and code paths where skbs > are released within the network stack. If my understanding of the code is correct, pktgen operates in the same way with parameter clone_skb = 0 and clone_skb = 1. clone_skb = 0 is already meant to work on devices that don't support shared skbs (see IFF_TX_SKB_SHARING check in pktgen_if_write()). Instead of introducing a new option for your purpose, how about changing pktgen_xmit() to send "not shared" skbs when clone_skb == 0? Note that for devices without IFF_TX_SKB_SHARING, it would no longer be possible to have pktgen free skbs. Is that important?