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From: Marek Kierdelewicz <marek@piasta.pl>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: netfilter@vger.kernel.org, marek@piasta.pl
Subject: Re: netfilter performance dependent on arch
Date: Tue, 7 Feb 2012 20:48:49 +0100	[thread overview]
Message-ID: <20120207204849.707a8a1f@catus> (raw)
In-Reply-To: <20120207111120.1d9ab37a@nehalam.linuxnetplumber.net>

>That information is out of date.
>The bulk of the slow down in 64 bit was due to the fact that IOMMU
>(CONFIG_DMAR) was enabled. The IOMMU requires programming DMA registers
>on each packet which explains the extra overhead. After disabling
>DMA remapping, the 64 bit kernel is faster because the compiler has
>more registers and can generate better code.

Thanks a lot. That's very valuable info.

Best regards,
Marek Kierdelewicz

      reply	other threads:[~2012-02-07 19:48 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-07 17:34 netfilter performance dependent on arch Marek Kierdelewicz
2012-02-07 18:23 ` Rick Jones
2012-02-07 18:54   ` Marek Kierdelewicz
2012-02-07 19:11     ` Stephen Hemminger
2012-02-07 19:48       ` Marek Kierdelewicz [this message]

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