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 E9445A04E7; Sun, 1 Nov 2020 21:07:50 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id B99A92BD3; Sun, 1 Nov 2020 21:00:22 +0100 (CET) Received: from shelob.oktetlabs.ru (shelob.oktetlabs.ru [91.220.146.113]) by dpdk.org (Postfix) with ESMTP id E14B82B9D for ; Sun, 1 Nov 2020 21:00:20 +0100 (CET) Received: from [192.168.1.70] (unknown [188.170.76.110]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by shelob.oktetlabs.ru (Postfix) with ESMTPSA id DC9617F528; Sun, 1 Nov 2020 23:00:17 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 shelob.oktetlabs.ru DC9617F528 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=oktetlabs.ru; s=default; t=1604260819; bh=tE0mWyaACnbTVjeSc29MIA6tAptGUeFZM18/oIe3dqs=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=QehQI86fwHox1GP6vSVUxfcTFvepyv5xk665cBVzuRSlQ1gdTq7IsrHgJnnOUhri/ BeIeTpaGuPDcKpHXTuqxdFZ4QN5cwmeFOoDeZ+Y9k8ChCwPz2VHVKS3bZbgQNff4lb EhLteVlTWwQXspsVFkYDCl7OCQFmA2tgl92H32bo= To: Jerin Jacob , Slava Ovsiienko Cc: NBU-Contact-Thomas Monjalon , "dev@dpdk.org" , "ferruh.yigit@intel.com" , "david.marchand@redhat.com" , "bruce.richardson@intel.com" , "olivier.matz@6wind.com" , "jerinj@marvell.com" , Nithin Dabilpuram , Kiran Kumar K , Ray Kinsella , Neil Horman References: <20201029092751.3837177-1-thomas@monjalon.net> <20201029092751.3837177-11-thomas@monjalon.net> <69cd6699-290f-102f-038a-f9fdde5874a1@oktetlabs.ru> From: Andrew Rybchenko Message-ID: <76a7dff3-bb57-ca7c-d8bd-029c21a70a18@oktetlabs.ru> Date: Sun, 1 Nov 2020 23:00:16 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] [PATCH 10/15] net/octeontx2: switch timestamp to dynamic mbuf field 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 10/30/20 3:41 PM, Jerin Jacob wrote: > On Thu, Oct 29, 2020 at 5:22 PM Slava Ovsiienko wrote: >> Just five cents - exporting the offset (making it global) might have side effect impacting the performance. > I agree with Slava. The offset value should be stored in the PMD structure. > IMO, We can have an ethdev API to get the offset and store it in PMD's > fastpath structures in the slow path > to use in fastpath. I don't mind. My main goal is to raise the topic and, may be, add a bit more comments in the code to help the future maintainers to understand it. It is not trivial topic and any help to code readers in the comments would be very useful. >> Offset might be located in some memory sharing the cacheline with some other variables. >> If these variables are writable and are being updated frequently - we might get the cache contention. >> I'd prefer to keep all dynamic offsets In the PMD and entirely control memory allocation >> attributes for these ones. Hence, exporting is OK, but practical usage in datapath is questionable. >> >> With best regards, Slava >> >>> -----Original Message----- >>> From: Andrew Rybchenko >>> Sent: Thursday, October 29, 2020 13:02 >>> To: NBU-Contact-Thomas Monjalon ; dev@dpdk.org >>> Cc: ferruh.yigit@intel.com; david.marchand@redhat.com; >>> bruce.richardson@intel.com; olivier.matz@6wind.com; jerinj@marvell.com; >>> Slava Ovsiienko ; Nithin Dabilpuram >>> ; Kiran Kumar K ; >>> Ray Kinsella ; Neil Horman >>> Subject: Re: [PATCH 10/15] net/octeontx2: switch timestamp to dynamic mbuf >>> field >>> >>> On 10/29/20 12:27 PM, Thomas Monjalon wrote: >>>> The mbuf timestamp is moved to a dynamic field in order to allow >>>> removal of the deprecated static field. >>>> The related mbuf flag is also replaced. >>>> >>>> Signed-off-by: Thomas Monjalon >>>> --- >>>> drivers/net/octeontx2/otx2_ethdev.c | 33 >>> +++++++++++++++++++++++++++++ >>>> drivers/net/octeontx2/otx2_rx.h | 19 ++++++++++++++--- >>>> drivers/net/octeontx2/version.map | 7 ++++++ >>>> 3 files changed, 56 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/drivers/net/octeontx2/otx2_ethdev.c >>>> b/drivers/net/octeontx2/otx2_ethdev.c >>>> index cfb733a4b5..ad95219438 100644 >>>> --- a/drivers/net/octeontx2/otx2_ethdev.c >>>> +++ b/drivers/net/octeontx2/otx2_ethdev.c >>>> @@ -4,6 +4,7 @@ >>>> >>>> #include >>>> >>>> +#include >>>> #include >>>> #include >>>> #include >>>> @@ -14,6 +15,35 @@ >>>> #include "otx2_ethdev.h" >>>> #include "otx2_ethdev_sec.h" >>>> >>>> +uint64_t rte_pmd_octeontx2_timestamp_rx_dynflag; >>>> +int rte_pmd_octeontx2_timestamp_dynfield_offset = -1; >>>> + >>>> +static int >>>> +otx2_rx_timestamp_setup(uint16_t flags) { >>>> + int timestamp_rx_dynflag_offset; >>>> + >>>> + if ((flags & NIX_RX_OFFLOAD_TSTAMP_F) == 0) >>>> + return 0; >>>> + >>>> + rte_pmd_octeontx2_timestamp_dynfield_offset = >>> rte_mbuf_dynfield_lookup( >>>> + RTE_MBUF_DYNFIELD_TIMESTAMP_NAME, NULL); >>>> + if (rte_pmd_octeontx2_timestamp_dynfield_offset < 0) { >>>> + otx2_err("Failed to lookup timestamp field"); >>>> + return -rte_errno; >>>> + } >>>> + timestamp_rx_dynflag_offset = rte_mbuf_dynflag_lookup( >>>> + RTE_MBUF_DYNFLAG_RX_TIMESTAMP_NAME, NULL); >>>> + if (timestamp_rx_dynflag_offset < 0) { >>>> + otx2_err("Failed to lookup Rx timestamp flag"); >>>> + return -rte_errno; >>>> + } >>>> + rte_pmd_octeontx2_timestamp_rx_dynflag = >>>> + RTE_BIT64(timestamp_rx_dynflag_offset); >>>> + >>>> + return 0; >>>> +} >>>> + >>>> static inline uint64_t >>>> nix_get_rx_offload_capa(struct otx2_eth_dev *dev) { @@ -1874,6 >>>> +1904,9 @@ otx2_nix_configure(struct rte_eth_dev *eth_dev) >>>> dev->tx_offload_flags |= nix_tx_offload_flags(eth_dev); >>>> dev->rss_info.rss_grps = NIX_RSS_GRPS; >>>> >>>> + if (otx2_rx_timestamp_setup(dev->rx_offload_flags) != 0) >>>> + goto fail_offloads; >>>> + >>>> nb_rxq = RTE_MAX(data->nb_rx_queues, 1); >>>> nb_txq = RTE_MAX(data->nb_tx_queues, 1); >>>> >>>> diff --git a/drivers/net/octeontx2/otx2_rx.h >>>> b/drivers/net/octeontx2/otx2_rx.h index 61a5c436dd..6981edce82 100644 >>>> --- a/drivers/net/octeontx2/otx2_rx.h >>>> +++ b/drivers/net/octeontx2/otx2_rx.h >>>> @@ -63,6 +63,18 @@ union mbuf_initializer { >>>> uint64_t value; >>>> }; >>>> >>>> +/* variables are exported because this file is included in other >>>> +drivers */ extern uint64_t rte_pmd_octeontx2_timestamp_rx_dynflag; >>>> +extern int rte_pmd_octeontx2_timestamp_dynfield_offset; >>>> + >>>> +static inline rte_mbuf_timestamp_t * >>>> +otx2_timestamp_dynfield(struct rte_mbuf *mbuf) { >>>> + return RTE_MBUF_DYNFIELD(mbuf, >>>> + rte_pmd_octeontx2_timestamp_dynfield_offset, >>>> + rte_mbuf_timestamp_t *); >>>> +} >>>> + >>> May be ethdev should provide the inline function? >> Just five cents - exporting the offset (making it global) might have side effect impacting the performance. >> Offset might be located in some memory sharing the cacheline with some other variables. >> If these variables are writable and are being updated frequently - we might get the cache contention. >> I'd prefer to keep all dynamic offsets In the PMD and entirely control memory allocation >> attributes for these ones. Hence, exporting/inline function is possible, >> but practical usage, say, in datapath, is questionable. >> >> With best regards, Slava >>