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From: Stephen Hemminger <stephen@networkplumber.org>
To: Nandini Rangaswamy <nandini.rangaswamy@broadcom.com>
Cc: Long Li <longli@microsoft.com>, "users@dpdk.org" <users@dpdk.org>
Subject: Re: Netvsc vs Failsafe Performance
Date: Thu, 12 Sep 2024 16:09:48 -0700	[thread overview]
Message-ID: <20240912160948.3714f01d@hermes.local> (raw)
In-Reply-To: <CAAkQrK8uYciOV+-tgEvtGhE1UGTqyQ__zio1nVisXso6VfRp-g@mail.gmail.com>

On Thu, 12 Sep 2024 13:47:37 -0700
Nandini Rangaswamy <nandini.rangaswamy@broadcom.com> wrote:

> Thanks for your response Long Li.
> I see with netvsc the maximum number of Tx descriptors is restricted to
> 4096 whereas the number of Rx descriptors is restricted to 8192.
> But, for failsafe PMD , we see that both the number of Txd and Rxd is
> restricted to 8192.
> How is netvsc PMD giving the same performance as failsafe PMD ?
> 
> Regards

I think the limits there were somewhat arbitrary chose with netvsc.
Don't remember a hard reason that would block larger sizes.


Having really big rings won't help performance (i.e BufferBloat) and
could a lot of memory consumption. When all heavy data traffic goes through
the VF and that ring is different. Only DoS attacks should be impacted
by rx/tx descriptor limits in the netvsc device. The linux driver actually
has much smaller buffer.

  reply	other threads:[~2024-09-12 23:09 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-03 21:43 Nandini Rangaswamy
2024-09-04  0:03 ` Stephen Hemminger
2024-09-04  0:21   ` Nandini Rangaswamy
2024-09-04 22:42     ` Stephen Hemminger
2024-09-05  2:30       ` Long Li
2024-09-12 20:47         ` Nandini Rangaswamy
2024-09-12 23:09           ` Stephen Hemminger [this message]
2024-09-13 17:56             ` Nandini Rangaswamy
2024-09-13 21:27               ` Long Li
2024-09-13 21:29                 ` Nandini Rangaswamy
2024-09-16 22:58                   ` Nandini Rangaswamy
2024-09-17 21:56                     ` Long Li
2024-09-19 16:45                       ` Nandini Rangaswamy
2024-10-16 19:26                         ` Long Li
2024-10-17 18:32                           ` Nandini Rangaswamy
2024-09-12 22:02       ` Nandini Rangaswamy
2024-09-12 22:59         ` Stephen Hemminger

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