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Groups > linux.kernel > #1621062
| From | Niklas Cassel <niklas.cassel@axis.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH net-next] net: stmmac: set total length of the packet to be transmitted in TDES3 |
| Date | 2017-04-11 11:20 +0200 |
| Message-ID | <tv07U-50R-15@gated-at.bofh.it> (permalink) |
| References | <tuMoi-4s3-25@gated-at.bofh.it> <tuZER-4BD-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 04/11/2017 10:48 AM, Joao Pinto wrote: > > Hi Niklas, > > Às 7:33 PM de 4/10/2017, Niklas Cassel escreveu: >> From: Niklas Cassel <niklas.cassel@axis.com> >> >> Field FL/TPL in register TDES3 is not correctly set on GMAC4. >> TX appears to be functional on GMAC 4.10a even if this field is not set, >> however, to avoid relying on undefined behavior, set the length in TDES3. >> >> The field has a different meaning depending on if the TSE bit in TDES3 >> is set or not (TSO). However, regardless of the TSE bit, the field is >> not optional. The field is already set correctly when the TSE bit is set. >> >> Since there is no limit for the number of descriptors that can be >> used for a single packet, the field should be set to the sum of >> the buffers contained in: >> [<desc with First Descriptor bit set> ... <desc n> ... >> <desc with Last Descriptor bit set>], which should be equal to skb->len. >> >> Signed-off-by: Niklas Cassel <niklas.cassel@axis.com> > > Sounds fine to me. Did you check for performance improvement? Thanks. > Hello Joao, I could not see any difference with 1 TCP stream in iperf3 Without the patch: # ./iperf3-armhf -c 192.168.0.1 Connecting to host 192.168.0.1, port 5201 [ 4] local 192.168.0.105 port 51878 connected to 192.168.0.1 port 5201 [ 23.486426] random: fast init done [ ID] Interval Transfer Bandwidth Retr Cwnd [ 4] 0.00-1.00 sec 61.7 MBytes 517 Mbits/sec 0 294 KBytes [ 4] 1.00-2.00 sec 61.3 MBytes 515 Mbits/sec 0 294 KBytes [ 26.043850] random: crng init done [ 4] 2.00-3.00 sec 61.4 MBytes 515 Mbits/sec 0 294 KBytes [ 4] 3.00-4.00 sec 61.0 MBytes 512 Mbits/sec 0 294 KBytes [ 4] 4.00-5.00 sec 61.5 MBytes 516 Mbits/sec 0 294 KBytes [ 4] 5.00-6.00 sec 61.2 MBytes 514 Mbits/sec 0 294 KBytes [ 4] 6.00-7.00 sec 61.5 MBytes 516 Mbits/sec 0 294 KBytes [ 4] 7.00-8.00 sec 61.4 MBytes 515 Mbits/sec 0 294 KBytes [ 4] 8.00-9.00 sec 61.2 MBytes 514 Mbits/sec 0 294 KBytes [ 4] 9.00-10.00 sec 61.3 MBytes 514 Mbits/sec 0 294 KBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bandwidth Retr [ 4] 0.00-10.00 sec 614 MBytes 515 Mbits/sec 0 sender [ 4] 0.00-10.00 sec 613 MBytes 514 Mbits/sec receiver With the patch: # ./iperf3-armhf -c 192.168.0.1 Connecting to host 192.168.0.1, port 5201 [ 4] local 192.168.0.105 port 37696 connected to 192.168.0.1 port 5201 [ 85.266262] random: fast init done [ ID] Interval Transfer Bandwidth Retr Cwnd [ 4] 0.00-1.00 sec 62.1 MBytes 520 Mbits/sec 0 288 KBytes [ 4] 1.00-2.00 sec 61.0 MBytes 512 Mbits/sec 0 288 KBytes [ 87.782547] random: crng init done [ 4] 2.00-3.00 sec 61.3 MBytes 515 Mbits/sec 0 300 KBytes [ 4] 3.00-4.00 sec 61.1 MBytes 512 Mbits/sec 0 300 KBytes [ 4] 4.00-5.00 sec 61.4 MBytes 515 Mbits/sec 0 300 KBytes [ 4] 5.00-6.00 sec 61.1 MBytes 513 Mbits/sec 0 300 KBytes [ 4] 6.00-7.00 sec 61.1 MBytes 513 Mbits/sec 0 300 KBytes [ 4] 7.00-8.00 sec 61.6 MBytes 517 Mbits/sec 0 300 KBytes [ 4] 8.00-9.00 sec 61.3 MBytes 515 Mbits/sec 0 300 KBytes [ 4] 9.00-10.00 sec 61.6 MBytes 517 Mbits/sec 0 300 KBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bandwidth Retr [ 4] 0.00-10.00 sec 614 MBytes 515 Mbits/sec 0 sender [ 4] 0.00-10.00 sec 613 MBytes 514 Mbits/sec receiver Note that the results above are with TSO off. With TSO on, I get 921 Mbps. However, the patch should not affect the case where TSO is on. Regards, Niklas
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[PATCH net-next] net: stmmac: set total length of the packet to be transmitted in TDES3 Niklas Cassel <niklas.cassel@axis.com> - 2017-04-10 20:40 +0200
Re: [PATCH net-next] net: stmmac: set total length of the packet to be transmitted in TDES3 Giuseppe CAVALLARO <peppe.cavallaro@st.com> - 2017-04-11 07:50 +0200
Re: [PATCH net-next] net: stmmac: set total length of the packet to be transmitted in TDES3 Alexandre Torgue <alexandre.torgue@st.com> - 2017-04-11 09:30 +0200
Re: [PATCH net-next] net: stmmac: set total length of the packet to be transmitted in TDES3 Joao Pinto <Joao.Pinto@synopsys.com> - 2017-04-11 10:50 +0200
Re: [PATCH net-next] net: stmmac: set total length of the packet to be transmitted in TDES3 Niklas Cassel <niklas.cassel@axis.com> - 2017-04-11 11:20 +0200
Re: [PATCH net-next] net: stmmac: set total length of the packet to be transmitted in TDES3 Giuseppe CAVALLARO <peppe.cavallaro@st.com> - 2017-04-11 14:50 +0200
Re: [PATCH net-next] net: stmmac: set total length of the packet to be transmitted in TDES3 David Miller <davem@davemloft.net> - 2017-04-13 18:50 +0200
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