From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Malli <mchilakala@gmail.com>
Cc: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
David Miller <davem@davemloft.net>,
netdev@vger.kernel.org
Subject: Re: ixgbe: Set IXGBE_RSC_CB(skb)->DMA field to zero after unmapping the address
Date: Wed, 24 Mar 2010 10:40:53 +1100 [thread overview]
Message-ID: <1269387653.8599.132.camel@pasglop> (raw)
In-Reply-To: <7991c5481003231040u3479778dpcb27d9578383afc0@mail.gmail.com>
On Tue, 2010-03-23 at 10:40 -0700, Malli wrote:
>
> Yes. I just realized that i can't assign a zero magic "bad" value. It
> is only
> valid in x86/arm/m68k/alpha architecures and not in spark & PowerPC
> arch,
> (it should be ~0). In some other architecutres it throws a BUG() on
> with
> dma_mapping_error() checks. So the patch is not a total bogus in some
> architectures :(.
>
> May be it is best to create an internal FLAG in IXGBE_RSC_CB(skb)
> which can be used to avoid this double freeing.
I suppose if Linus reads that he'll just come back and say "you idiots,
just make 0 invalid everywhere" like he did for interrupts tho :-) It
wouldn't be too hard for us to make the IOMMU allocator always skip "0".
But for now, I'd suggest you add a flag.
Cheers,
Ben.
prev parent reply other threads:[~2010-03-23 23:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <201003221759.o2MHxEaj015546@hera.kernel.org>
2010-03-23 3:57 ` ixgbe: Set IXGBE_RSC_CB(skb)->DMA field to zero after unmapping the address Benjamin Herrenschmidt
2010-03-23 17:40 ` Malli
2010-03-23 23:40 ` Benjamin Herrenschmidt [this message]
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=1269387653.8599.132.camel@pasglop \
--to=benh@kernel.crashing.org \
--cc=davem@davemloft.net \
--cc=linux-kernel@vger.kernel.org \
--cc=mallikarjuna.chilakala@intel.com \
--cc=mchilakala@gmail.com \
--cc=netdev@vger.kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).