linux-xfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dave Chinner <david@fromorbit.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
	"Darrick J. Wong" <darrick.wong@oracle.com>,
	Qu Wenruo <quwenruo@cn.fujitsu.com>,
	xfs@oss.sgi.com, linux-mm@kvack.org,
	Ingo Molnar <mingo@kernel.org>
Subject: Re: Xfs lockdep warning with for-dave-for-4.6 branch
Date: Wed, 19 Oct 2016 11:33:09 +1100	[thread overview]
Message-ID: <20161019003309.GG23194@dastard> (raw)
In-Reply-To: <20161006130454.GI10570@dhcp22.suse.cz>

On Thu, Oct 06, 2016 at 03:04:54PM +0200, Michal Hocko wrote:
> [Let me ressurect this thread]
> 
> On Wed 01-06-16 20:16:17, Peter Zijlstra wrote:
> > On Wed, Jun 01, 2016 at 03:17:58PM +0200, Michal Hocko wrote:
> > > Thanks Dave for your detailed explanation again! Peter do you have any
> > > other idea how to deal with these situations other than opt out from
> > > lockdep reclaim machinery?
> > > 
> > > If not I would rather go with an annotation than a gfp flag to be honest
> > > but if you absolutely hate that approach then I will try to check wheter
> > > a CONFIG_LOCKDEP GFP_FOO doesn't break something else. Otherwise I would
> > > steal the description from Dave's email and repost my patch.
> > > 
> > > I plan to repost my scope gfp patches in few days and it would be good
> > > to have some mechanism to drop those GFP_NOFS to paper over lockdep
> > > false positives for that.
> > 
> > Right; sorry I got side-tracked in other things again.
> > 
> > So my favourite is the dedicated GFP flag, but if that's unpalatable for
> > the mm folks then something like the below might work. It should be
> > similar in effect to your proposal, except its more limited in scope.
> 
> OK, so the situation with the GFP flags is somehow relieved after 
> http://lkml.kernel.org/r/20160912114852.GI14524@dhcp22.suse.cz and with
> the root radix tree remaining the last user which mangles gfp_mask and
> tags together we have some few bits left there. As you apparently hate
> any scoped API and Dave thinks that per allocation flag is the only
> maintainable way for xfs what do you think about the following?

It's a workable solution to allow XFS to play whack-a-mole games
with lockdep again. As to the implementation - that's for other
people to decide....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

  parent reply	other threads:[~2016-10-19  0:33 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-12  5:53 Xfs lockdep warning with for-dave-for-4.6 branch Qu Wenruo
2016-05-12  5:57 ` Darrick J. Wong
2016-05-12  8:03   ` Dave Chinner
2016-05-13 16:03     ` Michal Hocko
2016-05-16 10:41       ` Peter Zijlstra
2016-05-16 13:05         ` Michal Hocko
2016-05-16 13:25           ` Peter Zijlstra
2016-05-16 23:10             ` Dave Chinner
2016-05-17 14:49               ` Peter Zijlstra
2016-05-17 22:35                 ` Dave Chinner
2016-05-18  7:20                   ` Peter Zijlstra
2016-05-18  8:25                     ` Michal Hocko
2016-05-18  9:49                       ` Peter Zijlstra
2016-05-18 11:31                         ` Michal Hocko
2016-05-19  8:11                   ` Peter Zijlstra
2016-05-20  0:17                     ` Dave Chinner
2016-06-01 13:17                       ` Michal Hocko
2016-06-01 18:16                         ` Peter Zijlstra
2016-06-02 14:50                           ` Michal Hocko
2016-06-02 15:11                             ` Peter Zijlstra
2016-06-02 15:46                               ` Michal Hocko
2016-06-02 23:22                                 ` Dave Chinner
2016-06-06 12:20                                   ` Michal Hocko
2016-06-15  7:21                                     ` Dave Chinner
2016-06-21 14:26                                       ` Michal Hocko
2016-06-22  1:03                                         ` Dave Chinner
2016-06-22 12:38                                           ` Michal Hocko
2016-06-22 22:58                                             ` Dave Chinner
2016-06-23 11:35                                               ` Michal Hocko
2016-10-06 13:04                           ` Michal Hocko
2016-10-17 13:49                             ` Michal Hocko
2016-10-19  0:33                             ` Dave Chinner [this message]
2016-10-19  5:30                               ` Dave Chinner
2016-10-19  8:33                             ` Peter Zijlstra
2016-10-19 12:06                               ` Michal Hocko
2016-10-19 21:49                                 ` Dave Chinner
2016-10-20  7:15                                   ` Michal Hocko

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=20161019003309.GG23194@dastard \
    --to=david@fromorbit.com \
    --cc=darrick.wong@oracle.com \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=quwenruo@cn.fujitsu.com \
    --cc=xfs@oss.sgi.com \
    /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).