Re: [PATCH v2 net-next 00/14] mlx4: order-0 allocations and page recycling

On Thu, Feb 9, 2017 at 8:49 AM, Tariq Toukan [off-list ref] wrote:

On 09/02/2017 6:44 PM, Eric Dumazet wrote:

quoted

On Thu, Feb 9, 2017 at 8:41 AM, Tariq Toukan [off-list ref]
wrote:

quoted

Hi Eric,

Thanks again for your series.

On 09/02/2017 3:58 PM, Eric Dumazet wrote:

As mentioned half a year ago, we better switch mlx4 driver to order-0
allocations and page recycling.

This reduces vulnerability surface thanks to better skb->truesize
tracking and provides better performance in most cases.

v2 provides an ethtool -S new counter (rx_alloc_pages) and
code factorization, plus Tariq fix.

I see that you made significant changes to the previous series,
especially
patch 14 (RX CQE processing).
Please notice that our work week has just finished here in Israel.
I will review the series, especially the new patches (10 to 14), on
Sunday.

Default, out of box.

Well. Please report :

ethtool  -l eth0
ethtool -g eth0

quoted

quoted

- TCP 16 streams at 1KB length.

TCP does not really care, it coalesces all these into TSO skbs, full
size...

But the kernel stack has to split it back accordingly in the receive side,
no?

At 10Gbit or 40Gbit link speed, 16 TCP streams are sending 64KB TSO packets,
regardless of size of write() system calls.

Unless of course application uses write() with 1-byte, this might be
too expensive of course.