From: Dan Williams <dan.j.williams@intel.com>
To: Christoph Hellwig <hch@lst.de>
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
"Felix Kuehling" <Felix.Kuehling@amd.com>,
"Alex Deucher" <alexander.deucher@amd.com>,
"Christian König" <christian.koenig@amd.com>,
"Pan, Xinhui" <Xinhui.Pan@amd.com>,
"Ben Skeggs" <bskeggs@redhat.com>,
"Karol Herbst" <kherbst@redhat.com>,
"Lyude Paul" <lyude@redhat.com>, "Jason Gunthorpe" <jgg@ziepe.ca>,
"Alistair Popple" <apopple@nvidia.com>,
"Logan Gunthorpe" <logang@deltatee.com>,
"Ralph Campbell" <rcampbell@nvidia.com>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"amd-gfx list" <amd-gfx@lists.freedesktop.org>,
"Maling list - DRI developers" <dri-devel@lists.freedesktop.org>,
nouveau@lists.freedesktop.org,
"Linux NVDIMM" <nvdimm@lists.linux.dev>,
"Linux MM" <linux-mm@kvack.org>
Subject: Re: [PATCH 7/8] mm: remove the extra ZONE_DEVICE struct page refcount
Date: Tue, 8 Feb 2022 19:30:11 -0800 [thread overview]
Message-ID: <CAPcyv4h_axDTmkZ35KFfCdzMoOp8V3dc6btYGq6gCj1OmLXM=g@mail.gmail.com> (raw)
In-Reply-To: <20220207063249.1833066-8-hch@lst.de>
On Sun, Feb 6, 2022 at 10:33 PM Christoph Hellwig <hch@lst.de> wrote:
[..]
> @@ -500,28 +482,27 @@ void free_devmap_managed_page(struct page *page)
> */
> page->mapping = NULL;
> page->pgmap->ops->page_free(page);
> +
> + /*
> + * Reset the page count to 1 to prepare for handing out the page again.
> + */
> + set_page_count(page, 1);
Interesting. I had expected that to really fix the refcount problem
that fs/dax.c would need to start taking real page references as pages
were added to a mapping, just like page cache.
This looks ok to me, and passes my tests. So given I'm still working
my way back to fixing the references properly I'm ok for this hack to
replace the more broken hack that is there presently.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
next prev parent reply other threads:[~2022-02-09 3:30 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-07 6:32 start sorting out the ZONE_DEVICE refcount mess Christoph Hellwig
2022-02-07 6:32 ` [PATCH 1/8] mm: remove a pointless CONFIG_ZONE_DEVICE check in memremap_pages Christoph Hellwig
2022-02-07 18:08 ` Dan Williams
2022-02-07 19:22 ` Jason Gunthorpe
2022-02-08 7:17 ` Chaitanya Kulkarni
2022-02-08 8:06 ` Muchun Song
2022-02-07 6:32 ` [PATCH 2/8] mm: remove the __KERNEL__ guard from <linux/mm.h> Christoph Hellwig
2022-02-07 18:08 ` Dan Williams
2022-02-07 19:26 ` Jason Gunthorpe
2022-02-08 7:21 ` Chaitanya Kulkarni
2022-02-08 8:07 ` Muchun Song
2022-02-07 6:32 ` [PATCH 3/8] mm: remove pointless includes from <linux/hmm.h> Christoph Hellwig
2022-02-07 14:01 ` Jason Gunthorpe
2022-02-08 7:27 ` Chaitanya Kulkarni
2022-02-07 6:32 ` [PATCH 4/8] mm: move free_devmap_managed_page to memremap.c Christoph Hellwig
2022-02-07 19:06 ` Dan Williams
2022-02-07 19:27 ` Jason Gunthorpe
2022-02-08 7:34 ` Chaitanya Kulkarni
2022-02-08 8:09 ` Muchun Song
2022-02-07 6:32 ` [PATCH 5/8] mm: simplify freeing of devmap managed pages Christoph Hellwig
2022-02-07 19:34 ` Jason Gunthorpe
2022-02-07 23:42 ` Dan Williams
2022-02-08 7:50 ` Chaitanya Kulkarni
2022-02-07 6:32 ` [PATCH 6/8] mm: don't include <linux/memremap.h> in <linux/mm.h> Christoph Hellwig
2022-02-07 17:38 ` Logan Gunthorpe
2022-02-07 19:35 ` Jason Gunthorpe
2022-02-07 21:19 ` Felix Kuehling
2022-02-08 6:46 ` Christoph Hellwig
2022-02-09 17:48 ` Christoph Hellwig
2022-02-10 2:10 ` Alistair Popple
2022-02-10 6:45 ` Christoph Hellwig
2022-02-10 21:00 ` Felix Kuehling
2022-02-07 23:49 ` Dan Williams
2022-02-08 23:53 ` Dan Williams
2022-02-09 6:22 ` Christoph Hellwig
2022-02-07 6:32 ` [PATCH 7/8] mm: remove the extra ZONE_DEVICE struct page refcount Christoph Hellwig
2022-02-07 19:21 ` Jason Gunthorpe
2022-02-08 2:25 ` Ralph Campbell
2022-02-09 3:30 ` Dan Williams [this message]
2022-02-09 6:23 ` Christoph Hellwig
2022-02-09 12:29 ` Jason Gunthorpe
2022-02-09 13:53 ` Christoph Hellwig
2022-02-09 14:14 ` Jason Gunthorpe
2022-02-07 6:32 ` [PATCH 8/8] fsdax: depend on ZONE_DEVICE || FS_DAX_LIMITED Christoph Hellwig
2022-02-07 19:36 ` Jason Gunthorpe
2022-02-07 23:51 ` start sorting out the ZONE_DEVICE refcount mess Logan Gunthorpe
2022-02-08 3:03 ` Miaohe Lin
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