NVDIMM Device and Persistent Memory development
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From: Peter Xu <peterx@redhat.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>,
	linux-mm@kvack.org, david@fromorbit.com,
	dan.j.williams@intel.com, jhubbard@nvidia.com,
	rcampbell@nvidia.com, willy@infradead.org,
	linux-fsdevel@vger.kernel.org, jack@suse.cz, djwong@kernel.org,
	hch@lst.de, david@redhat.com, ruansy.fnst@fujitsu.com,
	nvdimm@lists.linux.dev, linux-xfs@vger.kernel.org,
	linux-ext4@vger.kernel.org, jglisse@redhat.com
Subject: Re: [RFC 02/10] mm/hmm: Remove dead check for HugeTLB and FS DAX
Date: Thu, 11 Apr 2024 09:37:33 -0400	[thread overview]
Message-ID: <ZhfnnYfqWKZn5Inh@x1n> (raw)
In-Reply-To: <20240411122530.GQ5383@nvidia.com>

On Thu, Apr 11, 2024 at 09:25:30AM -0300, Jason Gunthorpe wrote:
> On Thu, Apr 11, 2024 at 10:57:23AM +1000, Alistair Popple wrote:
> > pud_huge() returns true only for a HugeTLB page. pud_devmap() is only
> > used by FS DAX pages. These two things are mutually exclusive so this
> > code is dead code and can be removed.
> 
> I'm not sure this is true.. pud_huge() is mostly a misspelling of pud_leaf()..
> 
> > -	if (pud_huge(pud) && pud_devmap(pud)) {
> 
> I suspect this should be written as:
> 
>    if (pud_leaf(pud) && pud_devmap(pud)) {
> 
> In line with Peter's work here:
> 
> https://lore.kernel.org/linux-mm/20240321220802.679544-1-peterx@redhat.com/

Just to provide more information for Alistair, this patch already switched
that over to a _leaf():

https://lore.kernel.org/r/20240318200404.448346-12-peterx@redhat.com

That's in mm-unstable now, so should see that in a rebase.

And btw it's great to see that pxx_devmap() can go away.

Thanks,

-- 
Peter Xu


  reply	other threads:[~2024-04-11 13:37 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-11  0:57 [RFC 00/10] fs/dax: Fix FS DAX page reference counts Alistair Popple
2024-04-11  0:57 ` [RFC 01/10] mm/gup.c: Remove redundant check for PCI P2PDMA page Alistair Popple
2024-04-11 12:59   ` Jason Gunthorpe
2024-04-11 13:47   ` David Hildenbrand
2024-04-12  1:37     ` Alistair Popple
2024-04-11  0:57 ` [RFC 02/10] mm/hmm: Remove dead check for HugeTLB and FS DAX Alistair Popple
2024-04-11 12:25   ` Jason Gunthorpe
2024-04-11 13:37     ` Peter Xu [this message]
2024-04-12  1:28       ` Alistair Popple
2024-04-11  0:57 ` [RFC 03/10] pci/p2pdma: Don't initialise page refcount to one Alistair Popple
2024-04-11 12:29   ` Jason Gunthorpe
2024-04-12  5:40     ` Alistair Popple
2024-04-12 17:20   ` Dan Williams
2024-05-09 21:59   ` Logan Gunthorpe
2024-05-09 23:14     ` Alistair Popple
2024-04-11  0:57 ` [RFC 04/10] fs/dax: Don't track page mapping/index Alistair Popple
2024-04-12 15:22   ` Jan Kara
2024-04-12 17:31     ` Dan Williams
2024-04-15  7:03       ` Alistair Popple
2024-04-15 20:51         ` Dan Williams
2024-04-16  0:07           ` Alistair Popple
2024-04-16  0:36             ` Dan Williams
2024-04-12 17:21   ` Dan Williams
2024-04-11  0:57 ` [RFC 05/10] fs/dax: Refactor wait for dax idle page Alistair Popple
2024-04-12 14:37   ` Jan Kara
2024-04-13 20:19   ` John Hubbard
2024-04-15  8:41     ` Alistair Popple
2024-04-11  0:57 ` [RFC 06/10] fs/dax: Add dax_page_free callback Alistair Popple
2024-04-11  0:57 ` [RFC 07/10] mm: Allow compound zone device pages Alistair Popple
2024-04-11 12:32   ` Jason Gunthorpe
2024-04-11 14:10   ` Matthew Wilcox
2024-04-12  1:38     ` Alistair Popple
2024-04-11  0:57 ` [RFC 08/10] fs/dax: Properly refcount fs dax pages Alistair Popple
2024-04-11  0:57 ` [RFC 09/10] mm/khugepage.c: Warn if trying to scan devmap pmd Alistair Popple
2024-04-11 13:45   ` David Hildenbrand
2024-04-12  1:34     ` Alistair Popple
2024-04-11  0:57 ` [RFC 10/10] mm: Remove pXX_devmap Alistair Popple
2024-04-11 12:57   ` Jason Gunthorpe
2024-04-11 17:28 ` [RFC 00/10] fs/dax: Fix FS DAX page reference counts Dan Williams
2024-04-11 17:35   ` Jason Gunthorpe
2024-04-11 17:56     ` Dan Williams
2024-04-12  3:54   ` Alistair Popple
2024-04-12  6:55     ` Alistair Popple
2024-04-12 11:53       ` Jason Gunthorpe
2024-04-12 17:32         ` Dan Williams

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