From: Ralph Campbell <rcampbell@nvidia.com>
To: Ram Pai <linuxram@us.ibm.com>
Cc: <linux-mm@kvack.org>, <kvm-ppc@vger.kernel.org>,
<nouveau@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
Ira Weiny <ira.weiny@intel.com>,
Matthew Wilcox <willy@infradead.org>,
Jerome Glisse <jglisse@redhat.com>,
John Hubbard <jhubbard@nvidia.com>,
Alistair Popple <apopple@nvidia.com>,
"Christoph Hellwig" <hch@lst.de>,
Jason Gunthorpe <jgg@nvidia.com>,
Bharata B Rao <bharata@linux.ibm.com>, Zi Yan <ziy@nvidia.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Yang Shi <yang.shi@linux.alibaba.com>,
Paul Mackerras <paulus@ozlabs.org>,
Ben Skeggs <bskeggs@redhat.com>,
"Andrew Morton" <akpm@linux-foundation.org>
Subject: Re: [RFC PATCH v3 2/2] mm: remove extra ZONE_DEVICE struct page refcount
Date: Thu, 8 Oct 2020 09:45:55 -0700 [thread overview]
Message-ID: <751582db-9f03-dfbf-1466-131e051def37@nvidia.com> (raw)
In-Reply-To: <20201008051702.GA4773@ram-ibm-com.ibm.com>
On 10/7/20 10:17 PM, Ram Pai wrote:
> On Thu, Oct 01, 2020 at 11:17:15AM -0700, Ralph Campbell wrote:
>> ZONE_DEVICE struct pages have an extra reference count that complicates the
>> code for put_page() and several places in the kernel that need to check the
>> reference count to see that a page is not being used (gup, compaction,
>> migration, etc.). Clean up the code so the reference count doesn't need to
>> be treated specially for ZONE_DEVICE.
>
>
> I was hoping this patch would resolve a page-reference issue that we run
> into at random times while migrating a page to a device page backed by
> secure-memory.
>
> Unfortunately I continue to see the problem. There is a reference
> held on that page, which fails the migration.
>
> FYI
> RP
I'm willing to look into it but I would need more information.
Can you give any more details about the conditions when it happens?
It would be great if you have a program that reproduces the problem.
next prev parent reply other threads:[~2020-10-08 16:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-01 18:17 [RFC PATCH v3 0/2] mm: remove extra ZONE_DEVICE struct page refcount Ralph Campbell
2020-10-01 18:17 ` [RFC PATCH v3 1/2] ext4/xfs: add page refcount helper Ralph Campbell
2020-10-02 5:56 ` Christoph Hellwig
2020-10-05 16:29 ` Ralph Campbell
2020-10-01 18:17 ` [RFC PATCH v3 2/2] mm: remove extra ZONE_DEVICE struct page refcount Ralph Campbell
2020-10-02 5:59 ` Christoph Hellwig
2020-10-05 16:40 ` Ralph Campbell
2020-10-08 5:17 ` Ram Pai
2020-10-08 16:45 ` Ralph Campbell [this message]
2020-10-05 16:56 ` [RFC PATCH v3 0/2] " Matthew Wilcox
2020-10-05 18:24 ` Dan Williams
2021-05-13 13:15 ` Matthew Wilcox
2021-05-13 17:35 ` Ralph Campbell
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=751582db-9f03-dfbf-1466-131e051def37@nvidia.com \
--to=rcampbell@nvidia.com \
--cc=akpm@linux-foundation.org \
--cc=apopple@nvidia.com \
--cc=bharata@linux.ibm.com \
--cc=bskeggs@redhat.com \
--cc=dan.j.williams@intel.com \
--cc=hch@lst.de \
--cc=ira.weiny@intel.com \
--cc=jgg@nvidia.com \
--cc=jglisse@redhat.com \
--cc=jhubbard@nvidia.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kvm-ppc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linuxram@us.ibm.com \
--cc=nouveau@lists.freedesktop.org \
--cc=paulus@ozlabs.org \
--cc=willy@infradead.org \
--cc=yang.shi@linux.alibaba.com \
--cc=ziy@nvidia.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).