From: Ron Mercer <ron.mercer@qlogic.com>
To: David Miller <davem@davemloft.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [net-next PATCH 3/3] qlge: Increase default TX/RX ring size to 1024.
Date: Thu, 11 Jun 2009 16:21:59 -0700 [thread overview]
Message-ID: <20090611232159.GA13392@linux-ox1b.qlogic.org> (raw)
In-Reply-To: <20090611.022713.35602614.davem@davemloft.net>
> This is huge. Even other aggressive NICs such as BNX2X only use 256
> ring entries per TX queue.
>
> There is a point where increasing definitely hurts, because you're
> increasing the resident set size of the cpu, as more and more SKBs are
> effectively "in flight" at a given time and only due to the amount
> you're allowing to get queued up into the chip.
>
> And with multiqueue, per-queue TX queue sizes should matter less at
> least to some extent.
>
> Are you sure that jacking the value up this high has no negative side
> effects for various workloads?
Just drop this patch for now. I looked at our spreadsheet and ran the
tests again and we see a (marginal) throughput increase that leveled off
at TXQ length of 1024. In light of yours and Stephens comments I prefer
to revisit this issue.
next prev parent reply other threads:[~2009-06-11 23:29 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-11 1:49 [net-next PATCH 1/3] qlge: Relax alignment on TX harware queue Ron Mercer
2009-06-11 1:49 ` [net-next PATCH 2/3] qlge: Allow RX buf rings to be > than 4096 bytes Ron Mercer
2009-06-11 9:37 ` David Miller
2009-06-11 1:49 ` [net-next PATCH 3/3] qlge: Increase default TX/RX ring size to 1024 Ron Mercer
2009-06-11 9:27 ` David Miller
2009-06-11 15:34 ` Stephen Hemminger
2009-06-11 23:21 ` Ron Mercer [this message]
2009-06-11 23:50 ` David Miller
2009-06-11 9:37 ` [net-next PATCH 1/3] qlge: Relax alignment on TX harware queue David Miller
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