From: Keir Fraser <keir@xensource.com>
To: Roland Dreier <rdreier@cisco.com>,
Lukas Hejtmanek <xhejtman@ics.muni.cz>
Cc: xen-devel@lists.xensource.com
Subject: Re: Question regarding SLAB corruption
Date: Mon, 09 Jul 2007 23:30:12 +0100 [thread overview]
Message-ID: <C2B87584.A93A%keir@xensource.com> (raw)
In-Reply-To: <adaodilw8em.fsf@cisco.com>
On 9/7/07 22:53, "Roland Dreier" <rdreier@cisco.com> wrote:
> Although I'm a little confused about the earlier parts of the story.
> Why was it necessary to force the use of swiotlb? Shouldn't things
> work by default?
A swiotlb is a pre-allocated bounce-buffer region, so it has a memory cost
even if it's not actually used. Hence we do not create one by default for a
domU -- it has to be forced. Perhaps we could work out some way to detect
whether a swiotlb is likely to be needed, but our BUG_ON() messages are
pretty clear about why they are BUGging, and I considered that good enough.
> And is there any more intelligent way to give big chunks of system
> memory to a PCI device for exclusive use?
Perhaps dma_alloc_coherent/pci_alloc_consistent? These always return
machine-contiguous memory. I'm not sure if their use in this way would be an
abuse of the DMA API, though.
-- Keir
next prev parent reply other threads:[~2007-07-09 22:30 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-08 0:54 Question regarding SLAB corruption Lukas Hejtmanek
2007-07-08 9:59 ` Keir Fraser
2007-07-08 10:05 ` Lukas Hejtmanek
2007-07-08 10:11 ` Keir Fraser
2007-07-09 7:38 ` Lukas Hejtmanek
2007-07-09 8:02 ` Tian, Kevin
2007-07-09 8:31 ` Keir Fraser
2007-07-09 12:07 ` Lukas Hejtmanek
2007-07-09 12:47 ` Keir Fraser
2007-07-09 13:24 ` Lukas Hejtmanek
2007-07-09 13:42 ` Keir Fraser
2007-07-09 15:39 ` Lukas Hejtmanek
2007-07-09 16:13 ` Keir Fraser
2007-07-09 17:11 ` Lukas Hejtmanek
2007-07-09 17:21 ` Keir Fraser
2007-07-09 17:42 ` Lukas Hejtmanek
2007-07-09 18:29 ` Keir Fraser
2007-07-09 18:37 ` Lukas Hejtmanek
2007-07-09 18:46 ` Keir Fraser
2007-07-09 19:22 ` Keir Fraser
2007-07-09 19:43 ` Lukas Hejtmanek
2007-07-09 21:18 ` Keir Fraser
2007-07-09 21:26 ` Lukas Hejtmanek
2007-07-09 21:50 ` Lukas Hejtmanek
2007-07-09 19:25 ` Roland Dreier
2007-07-09 19:39 ` Keir Fraser
2007-07-09 20:56 ` Lukas Hejtmanek
2007-07-09 21:07 ` Roland Dreier
2007-07-09 21:14 ` Lukas Hejtmanek
2007-07-09 21:18 ` Roland Dreier
2007-07-09 21:42 ` Lukas Hejtmanek
2007-07-09 21:53 ` Roland Dreier
2007-07-09 22:13 ` Lukas Hejtmanek
2007-07-09 22:30 ` Keir Fraser [this message]
2007-07-09 22:30 ` Roland Dreier
2007-07-09 22:34 ` Keir Fraser
2007-07-10 18:47 ` Question: Dynamic code in x86_64 Xen Santos, Jose Renato G
2007-07-10 22:01 ` Keir Fraser
2007-07-10 22:06 ` Santos, Jose Renato G
2007-07-09 21:26 ` Question regarding SLAB corruption Roland Dreier
2007-07-09 21:33 ` Keir Fraser
2007-07-11 9:37 ` Question regarding vm creat&boot tgh
2007-07-09 19:21 ` Question regarding SLAB corruption Roland Dreier
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=C2B87584.A93A%keir@xensource.com \
--to=keir@xensource.com \
--cc=rdreier@cisco.com \
--cc=xen-devel@lists.xensource.com \
--cc=xhejtman@ics.muni.cz \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.