From: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux-nfs@vger.kernel.org, Jan Kara <jack@suse.cz>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Alexander Graf <agraf@suse.de>,
LKML List <linux-kernel@vger.kernel.org>,
"J. Bruce Fields" <bfields@fieldses.org>,
anton@samba.org, skinsbursky@parallels.com, bfields@redhat.com,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [REGRESSION] nfsd crashing with 3.6.0-rc7 on PowerPC
Date: Tue, 2 Oct 2012 14:43:27 -0700 [thread overview]
Message-ID: <20121002214327.GA29218@linux.vnet.ibm.com> (raw)
In-Reply-To: <1349139509.3847.2.camel@pasglop>
Hi Ben,
On 02.10.2012 [10:58:29 +1000], Benjamin Herrenschmidt wrote:
> On Mon, 2012-10-01 at 16:03 +0200, Alexander Graf wrote:
> > Phew. Here we go :). It looks to be more of a PPC specific problem
> > than it appeared as at first:
>
> Ok, so I suspect the problem is the pushing down of the locks which
> breaks with iommu backends that have a separate flush callback. In
> that case, the flush moves out of the allocator lock.
>
> Now we do call flush before we return, still, but it becomes racy
> I suspect, but somebody needs to give it a closer look. I'm hoping
> Anton or Nish will later today.
Started looking into this. If your suspicion were accurate, wouldn't the
bisection have stopped at 0e4bc95d87394364f408627067238453830bdbf3
("powerpc/iommu: Reduce spinlock coverage in iommu_alloc and
iommu_free")?
Alex, the error is reproducible, right? Does it go away by reverting
that commit against mainline? Just trying to narrow down my focus.
Thanks,
Nish
next prev parent reply other threads:[~2012-10-02 21:43 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-28 1:55 [REGRESSION] nfsd crashing with 3.6.0-rc7 on PowerPC Alexander Graf
2012-09-28 2:04 ` Linus Torvalds
2012-09-28 2:19 ` Alexander Graf
2012-09-28 15:10 ` J. Bruce Fields
2012-09-28 15:34 ` Alexander Graf
2012-10-01 14:03 ` Alexander Graf
2012-10-01 15:21 ` J. Bruce Fields
2012-10-02 0:58 ` Benjamin Herrenschmidt
2012-10-02 21:43 ` Nishanth Aravamudan [this message]
2012-10-02 21:47 ` Alexander Graf
2012-10-02 22:17 ` Nishanth Aravamudan
2012-10-02 22:31 ` Alexander Graf
2012-10-04 0:26 ` Anton Blanchard
2012-10-04 4:57 ` [PATCH] powerpc/iommu: Fix multiple issues with IOMMU pools code Anton Blanchard
2012-10-04 10:54 ` Alexander Graf
2012-10-03 4:22 ` [REGRESSION] nfsd crashing with 3.6.0-rc7 on PowerPC Benjamin Herrenschmidt
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=20121002214327.GA29218@linux.vnet.ibm.com \
--to=nacc@linux.vnet.ibm.com \
--cc=agraf@suse.de \
--cc=anton@samba.org \
--cc=benh@kernel.crashing.org \
--cc=bfields@fieldses.org \
--cc=bfields@redhat.com \
--cc=jack@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=skinsbursky@parallels.com \
--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 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).