lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sun, 28 Sep 2014 19:22:11 -0700
From:	Eric Dumazet <>
To:	Alexei Starovoitov <>
Cc:	Or Gerlitz <>,
	"David S. Miller" <>,
	Jesper Dangaard Brouer <>,
	Eric Dumazet <>,
	John Fastabend <>,
	Linux Netdev List <>,
	Amir Vadai <>,
	Or Gerlitz <>
Subject: Re: [PATCH net-next] mlx4: optimize xmit path

On Sun, 2014-09-28 at 13:49 -0700, Alexei Starovoitov wrote:

> I see. So xmit_more=true overrides blueflame=on settings.

Yes, unless Mellanox folks have another way.

> I wonder what is the performance difference bf=on vs bf=off,
> also whether a burst of N packets via bf is slower than
> burst via queue+doorbell.
> Some fun exploration for driver experts :)

Prior situation : bf=on : ~4.5 Mpps

queue + doorbell every 8 packets : ~8 Mpps, up to 10Mpps if tuned

Rewritten mlx4 tx path and no burst (bf=on doorbell at every packet) :
5.3 Mpps

With the full mlx4 patch and burst = 8 -> 14.9 Mpps

This is on a 40Gb NIC, with 108 bytes packets.

(Using <= 104 bytes packets actually gives lower pps because of
'inlining' done by the driver :  8 Mpps for PKTSIZE=40 )

# cat /sys/module/mlx4_en/parameters/inline_thold

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists