From: Bjorn Helgaas <helgaas@kernel.org>
To: Alistair Popple <apopple@nvidia.com>
Cc: dan.j.williams@intel.com, linux-mm@kvack.org,
vishal.l.verma@intel.com, dave.jiang@intel.com,
logang@deltatee.com, bhelgaas@google.com, jack@suse.cz,
jgg@ziepe.ca, catalin.marinas@arm.com, will@kernel.org,
mpe@ellerman.id.au, npiggin@gmail.com,
dave.hansen@linux.intel.com, ira.weiny@intel.com,
willy@infradead.org, djwong@kernel.org, tytso@mit.edu,
linmiaohe@huawei.com, david@redhat.com, peterx@redhat.com,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linuxppc-dev@lists.ozlabs.org, nvdimm@lists.linux.dev,
linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
jhubbard@nvidia.com, hch@lst.de, david@fromorbit.com
Subject: Re: [PATCH 02/12] pci/p2pdma: Don't initialise page refcount to one
Date: Wed, 11 Sep 2024 08:51:41 -0500 [thread overview]
Message-ID: <20240911135141.GA629523@bhelgaas> (raw)
In-Reply-To: <87r09rgfjj.fsf@nvdebian.thelocal>
On Wed, Sep 11, 2024 at 11:07:51AM +1000, Alistair Popple wrote:
>
> >> diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
> >> index 4f47a13..210b9f4 100644
> >> --- a/drivers/pci/p2pdma.c
> >> +++ b/drivers/pci/p2pdma.c
> >> @@ -129,6 +129,12 @@ static int p2pmem_alloc_mmap(struct file *filp, struct kobject *kobj,
> >> }
> >>
> >> /*
> >> + * Initialise the refcount for the freshly allocated page. As we have
> >> + * just allocated the page no one else should be using it.
> >> + */
> >> + set_page_count(virt_to_page(kaddr), 1);
> >
> > No doubt the subject line is true in some overall context, but it does
> > seem to say the opposite of what happens here.
>
> Fair. It made sense to me from the mm context I was coming from (it was
> being initialised to 1 there) but not overall. Something like "move page
> refcount initialisation to p2pdma driver" would make more sense?
Definitely would, thanks.
next prev parent reply other threads:[~2024-09-11 13:51 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-10 4:14 [PATCH 00/12] fs/dax: Fix FS DAX page reference counts Alistair Popple
2024-09-10 4:14 ` [PATCH 01/12] mm/gup.c: Remove redundant check for PCI P2PDMA page Alistair Popple
2024-09-22 1:00 ` Dan Williams
2024-09-10 4:14 ` [PATCH 02/12] pci/p2pdma: Don't initialise page refcount to one Alistair Popple
2024-09-10 13:47 ` Bjorn Helgaas
2024-09-11 1:07 ` Alistair Popple
2024-09-11 13:51 ` Bjorn Helgaas [this message]
2024-09-11 0:48 ` Logan Gunthorpe
2024-10-11 0:20 ` Alistair Popple
2024-09-22 1:00 ` Dan Williams
2024-10-11 0:17 ` Alistair Popple
2024-09-10 4:14 ` [PATCH 03/12] fs/dax: Refactor wait for dax idle page Alistair Popple
2024-09-22 1:01 ` Dan Williams
2024-09-10 4:14 ` [PATCH 04/12] mm: Allow compound zone device pages Alistair Popple
2024-09-10 4:47 ` Matthew Wilcox
2024-09-10 6:57 ` Alistair Popple
2024-09-10 13:41 ` Matthew Wilcox
2024-09-12 12:44 ` kernel test robot
2024-09-12 12:44 ` kernel test robot
2024-09-22 1:01 ` Dan Williams
2024-09-10 4:14 ` [PATCH 05/12] mm/memory: Add dax_insert_pfn Alistair Popple
2024-09-22 1:41 ` Dan Williams
2024-10-01 10:43 ` Gerald Schaefer
2024-09-10 4:14 ` [PATCH 06/12] huge_memory: Allow mappings of PUD sized pages Alistair Popple
2024-09-22 2:07 ` Dan Williams
2024-10-14 6:33 ` Alistair Popple
2024-09-10 4:14 ` [PATCH 07/12] huge_memory: Allow mappings of PMD " Alistair Popple
2024-09-27 2:48 ` Dan Williams
2024-10-14 6:53 ` Alistair Popple
2024-10-23 23:14 ` Alistair Popple
2024-10-23 23:38 ` Dan Williams
2024-09-10 4:14 ` [PATCH 08/12] gup: Don't allow FOLL_LONGTERM pinning of FS DAX pages Alistair Popple
2024-09-25 0:17 ` Dan Williams
2024-09-27 2:52 ` Dan Williams
2024-10-14 7:03 ` Alistair Popple
2024-09-10 4:14 ` [PATCH 09/12] mm: Update vm_normal_page() callers to accept " Alistair Popple
2024-09-27 7:15 ` Dan Williams
2024-10-14 7:16 ` Alistair Popple
2024-09-10 4:14 ` [PATCH 10/12] fs/dax: Properly refcount fs dax pages Alistair Popple
2024-09-27 7:59 ` Dan Williams
2024-10-24 7:52 ` Alistair Popple
2024-10-24 23:52 ` Dan Williams
2024-10-25 2:46 ` Alistair Popple
2024-10-25 4:35 ` Dan Williams
2024-10-28 4:24 ` Alistair Popple
2024-10-29 2:03 ` Dan Williams
2024-10-30 5:57 ` Alistair Popple
2024-09-10 4:14 ` [PATCH 11/12] mm: Remove pXX_devmap callers Alistair Popple
2024-09-27 12:29 ` Alexander Gordeev
2024-10-14 7:14 ` Alistair Popple
2024-09-10 4:14 ` [PATCH 12/12] mm: Remove devmap related functions and page table bits Alistair Popple
2024-09-11 7:47 ` Chunyan Zhang
2024-09-12 12:55 ` kernel test robot
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