From: Alessandro Rubini <rubini@gnudd.com>
To: davem@davemloft.net
Cc: peppe.cavallaro@st.com, netdev@vger.kernel.org, giancarlo.asnaghi@st.com
Subject: Re: [PATCH] stmmac: reduce queue lengths if MTU is very large
Date: Tue, 20 Dec 2011 08:30:50 +0100 [thread overview]
Message-ID: <20111220073050.GA2817@mail.gnudd.com> (raw)
In-Reply-To: <20111219.163337.1185514300243434827.davem@davemloft.net>
> This change doesn't make sense.
I disagree, but you are the boss here, so I accept that.
> I'm not applying this, it just points out that the amount of reserved
> space in your SWIOMMU setup might be insufficient for this situation
> rather than something that should be tweaked in this driver.
Allocation of the queues is based on a parameter. If the parameter was
a size, instead of a lenght, all would be fine, wouldn't it? If you
agree, then this patch is turning the lenght into a size, in a way.
Now, how could we deal with the fact that the size explodes if the MTU
is increased? I don't want to reserve and waste 16MB of RAM for a
single device: the device won't even use them for non-jumbo setups. I
can use the parameter to shorten the queue in all cases, but this is
not good either.
What's your suggestion?
thanks
/alessandro
next prev parent reply other threads:[~2011-12-20 7:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-19 5:45 [PATCH] stmmac: reduce queue lengths if MTU is very large Giuseppe CAVALLARO
2011-12-19 21:33 ` David Miller
2011-12-20 7:30 ` Alessandro Rubini [this message]
2011-12-20 18:41 ` David Miller
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