From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 0F1A2A046B for ; Thu, 25 Jul 2019 13:01:31 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 871521C2F1; Thu, 25 Jul 2019 13:01:30 +0200 (CEST) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by dpdk.org (Postfix) with ESMTP id EDA9B1C2EF; Thu, 25 Jul 2019 13:01:28 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jul 2019 04:01:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,306,1559545200"; d="scan'208";a="321631308" Received: from fyigit-mobl.ger.corp.intel.com (HELO [10.237.221.10]) ([10.237.221.10]) by orsmga004.jf.intel.com with ESMTP; 25 Jul 2019 04:01:26 -0700 To: David Marchand Cc: dev , dpdk stable , "A.McLoughlin" References: <1563969270-29669-1-git-send-email-david.marchand@redhat.com> <1563969270-29669-3-git-send-email-david.marchand@redhat.com> From: Ferruh Yigit Openpgp: preference=signencrypt Autocrypt: addr=ferruh.yigit@intel.com; prefer-encrypt=mutual; keydata= mQINBFXZCFABEADCujshBOAaqPZpwShdkzkyGpJ15lmxiSr3jVMqOtQS/sB3FYLT0/d3+bvy qbL9YnlbPyRvZfnP3pXiKwkRoR1RJwEo2BOf6hxdzTmLRtGtwWzI9MwrUPj6n/ldiD58VAGQ +iR1I/z9UBUN/ZMksElA2D7Jgg7vZ78iKwNnd+vLBD6I61kVrZ45Vjo3r+pPOByUBXOUlxp9 GWEKKIrJ4eogqkVNSixN16VYK7xR+5OUkBYUO+sE6etSxCr7BahMPKxH+XPlZZjKrxciaWQb +dElz3Ab4Opl+ZT/bK2huX+W+NJBEBVzjTkhjSTjcyRdxvS1gwWRuXqAml/sh+KQjPV1PPHF YK5LcqLkle+OKTCa82OvUb7cr+ALxATIZXQkgmn+zFT8UzSS3aiBBohg3BtbTIWy51jNlYdy ezUZ4UxKSsFuUTPt+JjHQBvF7WKbmNGS3fCid5Iag4tWOfZoqiCNzxApkVugltxoc6rG2TyX CmI2rP0mQ0GOsGXA3+3c1MCdQFzdIn/5tLBZyKy4F54UFo35eOX8/g7OaE+xrgY/4bZjpxC1 1pd66AAtKb3aNXpHvIfkVV6NYloo52H+FUE5ZDPNCGD0/btFGPWmWRmkPybzColTy7fmPaGz cBcEEqHK4T0aY4UJmE7Ylvg255Kz7s6wGZe6IR3N0cKNv++O7QARAQABtCVGZXJydWggWWln aXQgPGZlcnJ1aC55aWdpdEBpbnRlbC5jb20+iQJUBBMBCgA+AhsDAh4BAheABQkI71rKFiEE 0jZTh0IuwoTjmYHH+TPrQ98TYR8FAlznMMQFCwkIBwMFFQoJCAsFFgIDAQAACgkQ+TPrQ98T YR/B9Q//a57esjq996nfZVm7AsUl7zbvhN+Ojity25ib2gcSVVsAN2j6lcQS4hf6/OVvRj3q CgebJ4o2gXR6X12UzWBJL7NE8Xpc70MvUIe0r11ykurQ9n9jUaWMjxdSqBPF93hU+Z/MZe5M 1rW5O2VJLuTJzkDw3EYUCbHOwPjeaS8Qqj3RI0LYbGthbHBIp9CsjkgsJSjTT5GQ8AQWkE7I z+hvPx6f1rllfjxFyi4DI3jLhAI+j1Nm+l+ESyoX59HrLTHAvq4RPkLpTnGBj9gOnJ+5sVEr GE0fcffsNcuMSkpqSEoJCPAHmChoLgezskhhsy0BiU3xlSIj1Dx2XMDerUXFOK3ftlbYNRte HQy4EKubfZRB8H5Rvcpksom3fRBDcJT8zw+PTH14htRApU9f8I/RamQ7Ujks7KuaB7JX5QaG gMjfPzHGYX9PfF6KIchaFmAWLytIP1t0ht8LpJkjtvUCSQZ2VxpCXwKyUzPDIF3co3tp90o7 X07uiC5ymX0K0+Owqs6zeslLY6DMxNdt8ye+h1TVkSZ5g4dCs4C/aiEF230+luL1CnejOv/K /s1iSbXQzJNM7be3FlRUz4FdwsfKiJJF7xYALSBnSvEB04R7I2P2V9Zpudkq6DRT6HZjBeJ1 pBF2J655cdoenPBIeimjnnh4K7YZBzwOLJf2c6u76fe5Ag0EV9ZMvgEQAKc0Db17xNqtSwEv mfp4tkddwW9XA0tWWKtY4KUdd/jijYqc3fDD54ESYpV8QWj0xK4YM0dLxnDU2IYxjEshSB1T qAatVWz9WtBYvzalsyTqMKP3w34FciuL7orXP4AibPtrHuIXWQOBECcVZTTOdZYGAzaYzxiA ONzF9eTiwIqe9/oaOjTwTLnOarHt16QApTYQSnxDUQljeNvKYt1lZE/gAUUxNLWsYyTT+22/ vU0GDUahsJxs1+f1yEr+OGrFiEAmqrzpF0lCS3f/3HVTU6rS9cK3glVUeaTF4+1SK5ZNO35p iVQCwphmxa+dwTG/DvvHYCtgOZorTJ+OHfvCnSVjsM4kcXGjJPy3JZmUtyL9UxEbYlrffGPQ I3gLXIGD5AN5XdAXFCjjaID/KR1c9RHd7Oaw0Pdcq9UtMLgM1vdX8RlDuMGPrj5sQrRVbgYH fVU/TQCk1C9KhzOwg4Ap2T3tE1umY/DqrXQgsgH71PXFucVjOyHMYXXugLT8YQ0gcBPHy9mZ qw5mgOI5lCl6d4uCcUT0l/OEtPG/rA1lxz8ctdFBVOQOxCvwRG2QCgcJ/UTn5vlivul+cThi 6ERPvjqjblLncQtRg8izj2qgmwQkvfj+h7Ex88bI8iWtu5+I3K3LmNz/UxHBSWEmUnkg4fJl Rr7oItHsZ0ia6wWQ8lQnABEBAAGJAjwEGAEKACYCGwwWIQTSNlOHQi7ChOOZgcf5M+tD3xNh HwUCXOcvZgUJBvIWKAAKCRD5M+tD3xNhHxhBD/9toXMIaPIVFd9w1nKsRDM1GE6gZe4jie8q MJpeHB9O+936fSXA0W2X0het60wJQQ45O8TpTcxpc9nGzcE4MTaLAI3E8TjIXAO0cPqUNLyp g0DXezmTw5BU+SKZ51+jSKOtFmzJCHOJZQaMeCHD+G3CrdUHQVQBb5AeuH3KFv9ltgDcWsc8 YO70o3+tGHwcEnyXLdrI0q05wV7ncnLdkgVo+VUN4092bNMPwYly1TZWcU3Jw5gczOUEfTY7 sgo6E/sGX3B+FzgIs5t4yi1XOweCAQ/mPnb6uFeNENEFyGKyMG1HtjwBqnftbiFO3qitEIUY xWGQH23oKscv7i9lT0gg2D+ktzZhVWwHJVY/2vWSB9aCSWChcH2BT+lWrkwSpoPhy+almM84 Qz2wF72/d4ce4L27pSrS+vOXtXHLGOOGcAn8yr9TV0kM4aR+NbGBRXGKhG6w4lY54uNd9IBa ARIPUhij5JSygxZCBaJKo+X64AHGkk5bXq+f0anwAMNuJXbYC/lz4DEdKmPgQGShOWNs1Y1a N3cI87Hun/RBVwQ0a3Tr1g6OWJ6xK8cYbMcoR8NZ7L9ALMeJeuUDQR39+fEeHg/6sQN0P0mv 0sL+//BAJphCzDk8ztbrFw+JaPtgzZpRSM6JhxnY+YMAsatJRXA0WSpYP5zzl7yu/GZJIgsv VQ== Message-ID: Date: Thu, 25 Jul 2019 12:01:26 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-dev] [PATCH 2/3] net/pcap: fix transmit return count in error conditions X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 7/25/2019 8:40 AM, David Marchand wrote: > On Wed, Jul 24, 2019 at 8:36 PM Ferruh Yigit wrote: >> >> On 7/24/2019 12:54 PM, David Marchand wrote: >>> When a packet cannot be transmitted, the driver is supposed to free this >>> packet and report it as handled. >>> This is to prevent the application from retrying to send the same packet >>> and ending up in a liveloop since the driver will never manage to send >>> it. >>> >>> Fixes: 49a0a2ffd5db ("net/pcap: fix possible mbuf double freeing") >>> Fixes: 6db141c91e1f ("pcap: support jumbo frames") >>> CC: stable@dpdk.org >>> >>> Signed-off-by: David Marchand >>> --- >>> drivers/net/pcap/rte_eth_pcap.c | 18 ++++++++++-------- >>> 1 file changed, 10 insertions(+), 8 deletions(-) >>> >>> diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c >>> index 470867d..5e5aab7 100644 >>> --- a/drivers/net/pcap/rte_eth_pcap.c >>> +++ b/drivers/net/pcap/rte_eth_pcap.c >>> @@ -354,7 +354,8 @@ struct pmd_devargs_all { >>> mbuf->pkt_len, >>> RTE_ETHER_MAX_JUMBO_FRAME_LEN); >>> >>> - break; >>> + rte_pktmbuf_free(mbuf); >>> + continue; >> >> +1 >> Very recently 'rte_pktmbuf_free()' was moved because it wasn't compatible with >> return value, but this looks better, to free the mbuf and record it as error. >> >>> } >>> } >>> >>> @@ -373,7 +374,7 @@ struct pmd_devargs_all { >>> dumper_q->tx_stat.bytes += tx_bytes; >>> dumper_q->tx_stat.err_pkts += nb_pkts - num_tx; >>> >>> - return num_tx; >>> + return nb_pkts; >>> } >>> >>> /* >>> @@ -439,14 +440,15 @@ struct pmd_devargs_all { >>> mbuf->pkt_len, >>> RTE_ETHER_MAX_JUMBO_FRAME_LEN); >>> >>> - break; >>> + rte_pktmbuf_free(mbuf); >>> + continue; >>> } >>> } >>> >>> - if (unlikely(ret != 0)) >>> - break; >>> - num_tx++; >>> - tx_bytes += mbuf->pkt_len; >>> + if (ret == 0) { >>> + num_tx++; >>> + tx_bytes += mbuf->pkt_len; >>> + } >> >> I don't know this part, this is in 'eth_pcap_tx()' which writes packets to the >> interfaces. >> >> if 'pcap_sendpacket()' fails this doesn't mean packet can't be sent and may >> cause a liveloop. Why not keep the existing behavior and let application to decide? > > The manual is not clear to me. > Do we really have temporary situations where retries are fine? Same here, I am not that clear, I assume these situations exists, specially taking into account nobody complaining about existing implementation. > and if > so, can we differentiate them from things like incorrect permissions > etc... > > If we can't, dropping is safer. > May not differentiate them, because all we are getting is the fail from API without reason. But overall instead of driving freeing a packet, it feels better to leave this decision to application unless driver needs to free it. Other changes in the patchset is fixing defects in driver, only this part changes behavior without a clear defect, I am leaning to keep old behavior.