Re: UDP sockets oddities

2017-08-29 Thread Eric Dumazet
On Tue, 2017-08-29 at 10:53 -0700, Florian Fainelli wrote: > On 08/26/2017 11:56 AM, Florian Fainelli wrote: > > > > > > On 08/26/2017 05:47 AM, Eric Dumazet wrote: > >> On Fri, 2017-08-25 at 21:19 -0700, David Miller wrote: > >> > >>> Agreed, but the ARP resolution queue really needs to scale it

Re: UDP sockets oddities

2017-08-29 Thread Florian Fainelli
On 08/26/2017 11:56 AM, Florian Fainelli wrote: > > > On 08/26/2017 05:47 AM, Eric Dumazet wrote: >> On Fri, 2017-08-25 at 21:19 -0700, David Miller wrote: >> >>> Agreed, but the ARP resolution queue really needs to scale it's backlog >>> to the physical technology it is attached to. >> Yes, last

Re: UDP sockets oddities

2017-08-26 Thread Florian Fainelli
On 08/26/2017 05:47 AM, Eric Dumazet wrote: > On Fri, 2017-08-25 at 21:19 -0700, David Miller wrote: > >> Agreed, but the ARP resolution queue really needs to scale it's backlog >> to the physical technology it is attached to. > Yes, last time (in 2011) we increased the old limit of 3 packets :/

Re: UDP sockets oddities

2017-08-26 Thread Eric Dumazet
On Fri, 2017-08-25 at 21:19 -0700, David Miller wrote: > Agreed, but the ARP resolution queue really needs to scale it's backlog > to the physical technology it is attached to. Yes, last time (in 2011) we increased the old limit of 3 packets :/ We probably should match sysctl_wmem_max so that a s

Re: UDP sockets oddities

2017-08-25 Thread Eric Dumazet
On Fri, 2017-08-25 at 18:52 -0700, Eric Dumazet wrote: > I guess we should an SNMP counter for packets dropped in neigh queues. Info is already there : cat /proc/net/stat/arp_cache

Re: UDP sockets oddities

2017-08-25 Thread David Miller
From: Eric Dumazet Date: Fri, 25 Aug 2017 20:40:44 -0700 > On Fri, 2017-08-25 at 20:25 -0700, Florian Fainelli wrote: > >> It would. Since the call trace involves udp_send_skb() how come we are >> not returning an error to write(2)? are there other code paths where the >> neighbor code can do dr

Re: UDP sockets oddities

2017-08-25 Thread David Miller
From: Florian Fainelli Date: Fri, 25 Aug 2017 20:25:26 -0700 > It would. Since the call trace involves udp_send_skb() how come we are > not returning an error to write(2)? are there other code paths where the > neighbor code can do drops like these? Keep in mind that the neighbour code isn't dro

Re: UDP sockets oddities

2017-08-25 Thread Eric Dumazet
On Fri, 2017-08-25 at 20:25 -0700, Florian Fainelli wrote: > It would. Since the call trace involves udp_send_skb() how come we are > not returning an error to write(2)? are there other code paths where the > neighbor code can do drops like these? Are you suggesting write(2) should block until AR

Re: UDP sockets oddities

2017-08-25 Thread Florian Fainelli
On 08/25/2017 06:52 PM, Eric Dumazet wrote: > On Fri, 2017-08-25 at 18:17 -0700, Florian Fainelli wrote: >> On 08/25/2017 04:57 PM, Eric Dumazet wrote: >>> On Fri, 2017-08-25 at 16:18 -0700, Florian Fainelli wrote: >>> Eric, are there areas of the stack where we are allowed to drop packets,

Re: UDP sockets oddities

2017-08-25 Thread Eric Dumazet
On Fri, 2017-08-25 at 18:17 -0700, Florian Fainelli wrote: > On 08/25/2017 04:57 PM, Eric Dumazet wrote: > > On Fri, 2017-08-25 at 16:18 -0700, Florian Fainelli wrote: > > > >> Eric, are there areas of the stack where we are allowed to drop packets, > >> not propagate that back to write(2) and als

Re: UDP sockets oddities

2017-08-25 Thread Florian Fainelli
On 08/25/2017 04:57 PM, Eric Dumazet wrote: > On Fri, 2017-08-25 at 16:18 -0700, Florian Fainelli wrote: > >> Eric, are there areas of the stack where we are allowed to drop packets, >> not propagate that back to write(2) and also not increment any counter >> either, or maybe I am not looking wher

Re: UDP sockets oddities

2017-08-25 Thread Eric Dumazet
On Fri, 2017-08-25 at 16:18 -0700, Florian Fainelli wrote: > Eric, are there areas of the stack where we are allowed to drop packets, > not propagate that back to write(2) and also not increment any counter > either, or maybe I am not looking where I should... What happens if you increase these s

Re: UDP sockets oddities

2017-08-25 Thread Florian Fainelli
On 08/23/2017 07:23 PM, Florian Fainelli wrote: > On 08/23/2017 05:43 PM, Eric Dumazet wrote: >> On Wed, 2017-08-23 at 17:03 -0700, Florian Fainelli wrote: >> >>> Attached is the perf report --stdio of: >>> >>> # perf record -a -g -e skb:kfree_skb iperf -c 192.168.1.23 -b 800M -t 60 >>> WARNING: op

Re: UDP sockets oddities

2017-08-23 Thread Florian Fainelli
On 08/23/2017 05:43 PM, Eric Dumazet wrote: > On Wed, 2017-08-23 at 17:03 -0700, Florian Fainelli wrote: > >> Attached is the perf report --stdio of: >> >> # perf record -a -g -e skb:kfree_skb iperf -c 192.168.1.23 -b 800M -t 60 >> WARNING: option -b implies udp testing >>

Re: UDP sockets oddities

2017-08-23 Thread Eric Dumazet
On Wed, 2017-08-23 at 17:03 -0700, Florian Fainelli wrote: > Attached is the perf report --stdio of: > > # perf record -a -g -e skb:kfree_skb iperf -c 192.168.1.23 -b 800M -t 60 > WARNING: option -b implies udp testing > > Client connec

Re: UDP sockets oddities

2017-08-23 Thread Eric Dumazet
On Wed, 2017-08-23 at 15:49 -0700, Florian Fainelli wrote: > On 08/23/2017 03:26 PM, Eric Dumazet wrote: > > On Wed, 2017-08-23 at 13:02 -0700, Florian Fainelli wrote: > >> Hi, > >> > >> On Broadcom STB chips using bcmsysport.c and bcm_sf2.c we have an out of > >> band HW mechanism (not using per-f

Re: UDP sockets oddities

2017-08-23 Thread Florian Fainelli
On 08/23/2017 03:26 PM, Eric Dumazet wrote: > On Wed, 2017-08-23 at 13:02 -0700, Florian Fainelli wrote: >> Hi, >> >> On Broadcom STB chips using bcmsysport.c and bcm_sf2.c we have an out of >> band HW mechanism (not using per-flow pause frames) where we can have >> the integrated network switch ba

Re: UDP sockets oddities

2017-08-23 Thread Eric Dumazet
On Wed, 2017-08-23 at 13:02 -0700, Florian Fainelli wrote: > Hi, > > On Broadcom STB chips using bcmsysport.c and bcm_sf2.c we have an out of > band HW mechanism (not using per-flow pause frames) where we can have > the integrated network switch backpressure the CPU Ethernet controller > which tra

UDP sockets oddities

2017-08-23 Thread Florian Fainelli
Hi, On Broadcom STB chips using bcmsysport.c and bcm_sf2.c we have an out of band HW mechanism (not using per-flow pause frames) where we can have the integrated network switch backpressure the CPU Ethernet controller which translates in completing TX packets interrupts at the appropriate pace and