Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-07 Thread Dave Chinner
hich means it has zero coverage of the entire XFS metadata buffer subsystem and the complex locking orders we have for metadata updates. Put simply: lockdep doesn't provide me with any benefit, so I don't use it... Cheers, Dave. -- Dave Chinner da...@fromorbit.com -- To unsubscribe f

Re: Lockdep is less useful than it was

2017-12-07 Thread Dave Chinner
problem, you'd be happier, right? I'd be much happier if it wasn't turned on by default in the first place. We gave plenty of warnings that there were still unsolved false positive problems with the new checks in the storage stack. Cheers, Dave. -- Dave Chinner da...@fromorbit.com -- To unsubsc

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-07 Thread Dave Chinner
On Fri, Dec 08, 2017 at 01:45:52PM +0900, Byungchul Park wrote: > On Fri, Dec 08, 2017 at 09:22:16AM +1100, Dave Chinner wrote: > > On Thu, Dec 07, 2017 at 11:06:34AM -0500, Theodore Ts'o wrote: > > > On Wed, Dec 06, 2017 at 06:06:48AM -0800, Matthew Wilcox wrote: > > >

Re: [PATCH v4 00/73] XArray version 4

2017-12-05 Thread Dave Chinner
On Wed, Dec 06, 2017 at 12:45:49PM +1100, Dave Chinner wrote: > On Tue, Dec 05, 2017 at 04:40:46PM -0800, Matthew Wilcox wrote: > > From: Matthew Wilcox <mawil...@microsoft.com> > > > > I looked through some notes and decided this was version 4 of the XArray. &g

Re: [PATCH v4 00/73] XArray version 4

2017-12-05 Thread Dave Chinner
On Tue, Dec 05, 2017 at 04:40:46PM -0800, Matthew Wilcox wrote: > From: Matthew Wilcox <mawil...@microsoft.com> > > I looked through some notes and decided this was version 4 of the XArray. > Last posted two weeks ago, this version includes a *lot* of changes. > I'd like

Re: [PATCH v4 00/73] XArray version 4

2017-12-05 Thread Dave Chinner
his time. -Dave. > > > -Original Message----- > > From: Dave Chinner [mailto:da...@fromorbit.com] > > Sent: Tuesday, December 5, 2017 8:51 PM > > To: Matthew Wilcox <wi...@infradead.org> > > Cc: Matthew Wilcox <mawil...@microsoft.com>; Ross Zwisler > >

Re: [PATCH v4 00/73] XArray version 4

2017-12-05 Thread Dave Chinner
On Tue, Dec 05, 2017 at 06:05:15PM -0800, Matthew Wilcox wrote: > On Wed, Dec 06, 2017 at 12:45:49PM +1100, Dave Chinner wrote: > > On Tue, Dec 05, 2017 at 04:40:46PM -0800, Matthew Wilcox wrote: > > > From: Matthew Wilcox <mawil...@microsoft.com> > > >

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-05 Thread Dave Chinner
tions. Turning that around so that a larger XFS structure and algorithm is now protected by an opaque internal lock from generic storage structure the forms part of the larger structure seems like a bad design pattern to me... Cheers, Dave. -- Dave Chinner da...@fromorbit.com -- To un

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-05 Thread Dave Chinner
On Tue, Dec 05, 2017 at 06:02:08PM -0800, Matthew Wilcox wrote: > On Wed, Dec 06, 2017 at 12:36:48PM +1100, Dave Chinner wrote: > > > - if (radix_tree_preload(GFP_NOFS)) > > > - return -ENOMEM; > > > - > > > INIT_LIST_HEAD(>list_node); > >

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-11 Thread Dave Chinner
On Sat, Dec 09, 2017 at 09:00:18AM -0800, Joe Perches wrote: > On Sat, 2017-12-09 at 09:36 +1100, Dave Chinner wrote: > > 1. Using lockdep_set_novalidate_class() for anything other > > than device->mutex will throw checkpatch warnings. Nice. (*) > [] > > (*)

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-11 Thread Dave Chinner
On Sun, Dec 10, 2017 at 08:23:15PM -0800, Matthew Wilcox wrote: > On Mon, Dec 11, 2017 at 10:57:45AM +1100, Dave Chinner wrote: > > i.e. the fact the cmpxchg failed may not have anything to do with a > > race condtion - it failed because the slot wasn't empty like

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-06 Thread Dave Chinner
On Tue, Dec 05, 2017 at 08:45:49PM -0800, Matthew Wilcox wrote: > On Wed, Dec 06, 2017 at 02:14:56PM +1100, Dave Chinner wrote: > > > The other conversions use the normal API instead of the advanced API, so > > > all of this gets hidden away. For example, the inode cache d

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-06 Thread Dave Chinner
On Wed, Dec 06, 2017 at 06:06:48AM -0800, Matthew Wilcox wrote: > On Wed, Dec 06, 2017 at 07:44:04PM +1100, Dave Chinner wrote: > > On Tue, Dec 05, 2017 at 08:45:49PM -0800, Matthew Wilcox wrote: > > > That said, using xa_cmpxchg() in the dquot code looked like the right > &g

Re: Lockdep is less useful than it was

2017-12-08 Thread Dave Chinner
ructure just to add lockdep validation to a tree that doesn't actually need any extra locking validation... Cheers, Dave. -- Dave Chinner da...@fromorbit.com -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majo

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-10 Thread Dave Chinner
On Fri, Dec 08, 2017 at 03:01:31PM -0800, Matthew Wilcox wrote: > On Thu, Dec 07, 2017 at 11:38:43AM +1100, Dave Chinner wrote: > > > > cmpxchg is for replacing a known object in a store - it's not really > > > > intended for doing initial inserts after a lookup tells

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-11 Thread Dave Chinner
On Mon, Dec 11, 2017 at 02:12:28PM -0800, Joe Perches wrote: > On Tue, 2017-12-12 at 08:43 +1100, Dave Chinner wrote: > > On Sat, Dec 09, 2017 at 09:00:18AM -0800, Joe Perches wrote: > > > On Sat, 2017-12-09 at 09:36 +1100, Dave Chinner wrote: > > > > 1. Usin

Re: [PATCH v4 72/73] xfs: Convert mru cache to XArray

2017-12-08 Thread Dave Chinner
Who-ever adds semaphore checking to lockdep can add those annotations. The externalisation of the development cost of new lockdep functionality is one of the problems here. -Dave. (*) checkpatch.pl is considered mostly harmful round here, too, but that's another rant (**) the frequent occurren