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Date: Sat, 2 Feb 2008 21:54:16 -0800
From: "Kip Macy" <kip.macy@gmail.com>
To: "Aaditya Rai" <filesync@yahoo.com>
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Cc: freebsd-net@freebsd.org
Subject: Re: m_getjcl for contiguous jumbo allocations
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On Feb 2, 2008 8:46 PM, Aaditya Rai <filesync@yahoo.com> wrote:
> Hello,
>
> I'm using release 6.2. I need to do allocations upto
> 8K which are physically contiguous.
>
> Is m_getjcl the right call for this?
>
> Also, if I use m_getjcl to do 4K allocations, after
> two or three allocations I start getting cluster/mbuf
> allocation failures; or weird memory corruptions. If I
> change it to use MGETCL etc. and do 2K allocations,
> the same code works fine.
>
> Is m_getjcl() stable in 6.2? Should I fall back on
> implementing my own little backend contig-allocator?

On 6.2 you'll have to fall back your own allocator if you are unable
to chain 4k jumbo frames.

In -CURRENT physically contiguous jumbo frames are the default. I'm
not sure if that made it in to 7.0.


 -Kip