From: Ingo Molnar <mingo@elte.hu>
To: Pavel Machek <pavel@ucw.cz>
Cc: kernel list <linux-kernel@vger.kernel.org>,
andi@firstfloor.org, Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: iommu: it could use some documentation
Date: Wed, 19 Mar 2008 16:13:46 +0100 [thread overview]
Message-ID: <20080319151346.GA28798@elte.hu> (raw)
In-Reply-To: <20080319145811.GA27113@elf.ucw.cz>
* Pavel Machek <pavel@ucw.cz> wrote:
> Fix coding style in pci-dma_64.c and add stubs for documentation. I
> hope someone fills the rest, I understand maybe off and soft...
> + iommu= [x86]
> + off
> + force
> + noforce
> + biomerge
> + panic
> + nopanic
> + merge
> + nomerge
> + forcesac
> + soft
these are mostly quirks to get boards booting - few people use these for
performance tuning. SAC has an address space limit (40 bits) but is
faster, DAC can cover the physical address range but is slower. The
softiotlb we better forget about ;-)
if you are interested in fixing this, the descriptions from
Documentation/x86_64/boot-options.txt should/could be merged into
Documentation/kernel-parameters.txt.
Ingo
next prev parent reply other threads:[~2008-03-19 22:22 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-19 14:58 iommu: it could use some documentation Pavel Machek
2008-03-19 15:06 ` Ingo Molnar
2008-03-19 15:13 ` Ingo Molnar [this message]
2008-03-21 15:55 ` Andi Kleen
2008-03-21 15:53 ` Andi Kleen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20080319151346.GA28798@elte.hu \
--to=mingo@elte.hu \
--cc=andi@firstfloor.org \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox