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Message-ID: <alpine.DEB.2.00.1101161402430.29729@p34.internal.lan>
Date: Sun, 16 Jan 2011 14:08:11 -0500 (EST)
From: Justin Piszcz <jpiszcz@...idpixels.com>
To: "Ian E. Morgan" <penguin.wrangler@...il.com>
cc: linux-kernel@...r.kernel.org, linux-net@...r.kernel.org,
Alan Piszcz <ap@...arrain.com>
Subject: Re: Only ~85MiB/s (e1000e/write) to ~310MiB/s RAID-0 on ATOM
board?
On Sun, 16 Jan 2011, Ian E. Morgan wrote:
> Justin,
>
> I have two Supermicro 5015a-EHF-D525's. They use the same Intel 82574L
> NICs as your slightly older board.
> I asked myself the same questions as you just recently, and my
> research into multi-queue NIC support led to:
>
> Receive Packet Steering
>
> Take a look at the output of NET_TX and NET_RX in /proc/softirq.
> The interrupts were not balanced across the cpus until I did:
>
> echo f > /sys/devices/pci0000:00/0000:00:1c.1/0000:02:00.0/net/eth0/queues/rx-0/rps_cpus
> ("f" being a bitmask of cpus)
>
> Then the interrupts started balancing across all cpus.
> I haven't had a chance to try this in a high throughput transfer
> situation yet, as I just happened to look into this last night.
>
> Hope it leads you down the right path, and please let me know if it
> does or doesn't help, or any other solutions you've found or come up
> with.
>
> --
> Ian Morgan
Hi Ian,
Thanks for the response & suggestion!
Tried it on kernel 2.6.37:
Made sure it was enabled:
# grep RPS .config
CONFIG_RPS=y
Only achieved 79.98M/s on > 4 GB of data via FTP (downloading), does not
appear to change much.
# cat /sys/class/net/eth1/queues/rx-0/rps_cpus
0
# echo f > /sys/class/net/eth1/queues/rx-0/rps_cpus
# cat /sys/class/net/eth1/queues/rx-0/rps_cpus
f
#
# cat /proc/softirqs
CPU0 CPU1 CPU2 CPU3
HI: 0 0 0 0
TIMER: 508490 507869 508325 508253
NET_TX: 22933 24274 23800 22124
NET_RX: 94412 218903 93273 95787
BLOCK: 63945 22646 21324 8084
BLOCK_IOPOLL: 0 0 0 0
TASKLET: 8 4 2 5
SCHED: 244572 218617 262071 242491
HRTIMER: 0 0 0 0
RCU: 52859 53519 53715 55199
What speed(s) do you achieve with the D525s?
If anyone finds out why these boards cannot achieve > 90-100MiB/s to disk,
I'd be curious to know why, thanks.
Justin.
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