From: Joerg Roedel <joro@8bytes.org>
To: Daniel J Blueman <daniel.blueman@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [2.6.35-rc3] select useful number of entries for DMA debugging...
Date: Sat, 10 Jul 2010 17:43:31 +0200 [thread overview]
Message-ID: <20100710154331.GF10080@8bytes.org> (raw)
In-Reply-To: <AANLkTinLjhLoQJ8URiuCKqgntiLEKxCesNEPZ8b24uLu@mail.gmail.com>
On Sat, Jul 10, 2010 at 03:52:04PM +0100, Daniel J Blueman wrote:
> On 9 July 2010 22:33, Linus Torvalds <torvalds@linux-foundation.org> wrote:
> > On Mon, Jul 5, 2010 at 1:35 AM, Daniel J Blueman
> > <daniel.blueman@gmail.com> wrote:
> >> When booting 2.6.35-rc3 on some different x86 boxes with DMA debugging
> >> enabled, I've consistently seen it exhaust the allocated entries during
> >> boot, giving 'DMA-API: debugging out of memory - disabling'.
> >>
> >> Increase number of entries to allow DMA debugging again.
> >
> > Rather than increase the default that gets allocated whenever anybody
> > enables the DMA debugging, I'd really prefer to see people use the
> > kernel command line option if they run out. After all, it's a (pretty
> > esoteric) debug option, and the number of required entries depends on
> > machine configuration. I'd rather not make the default cover a huge
> > number, when you could just add
> >
> > dma_debug_entries=65536
> >
> > on the kernel boot command line instead for machines that want/need it..
>
> That said, I am seeing the DMA pool exhaust on a single socket Core i5
> system with Intel graphics and no other adapters - seems like a fairly
> common case. If eg 25% of developers will be using similar to this,
> maybe it's good to make DMA debugging less immediately esoteric?
>
> On the other hand, I would immediately agree if the exhaustion
> occurred on an atypical setup.
How much memory do you have in this machine? We could probably make the
number of pre-allocated entries dependent on the memory available in the
machine like Ingo suggested some time ago to avoid such problems.
Joerg
next prev parent reply other threads:[~2010-07-10 15:43 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-05 8:35 [2.6.35-rc3] select useful number of entries for DMA debugging Daniel J Blueman
2010-07-09 21:33 ` Linus Torvalds
2010-07-10 14:52 ` Daniel J Blueman
2010-07-10 15:43 ` Joerg Roedel [this message]
2010-07-11 11:54 ` Daniel J Blueman
2010-07-11 13:00 ` Daniel J Blueman
2010-07-12 14:39 ` John Stoffel
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=20100710154331.GF10080@8bytes.org \
--to=joro@8bytes.org \
--cc=daniel.blueman@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
/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.