From: John Hubbard <jhubbard@nvidia.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: "Jan Kara" <jack@suse.cz>, "Christoph Hellwig" <hch@lst.de>,
"Jérôme Glisse" <jglisse@redhat.com>,
linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Subject: Re: [PATCH] mm: Cleanup __put_devmap_managed_page() vs ->page_free()
Date: Wed, 13 Nov 2019 16:39:17 -0800 [thread overview]
Message-ID: <913133b7-58d8-9645-fc89-c2819825e1ee@nvidia.com> (raw)
In-Reply-To: <157368992671.2974225.13512647385398246617.stgit@dwillia2-desk3.amr.corp.intel.com>
On 11/13/19 4:07 PM, Dan Williams wrote:
> After the removal of the device-public infrastructure there are only 2
> ->page_free() call backs in the kernel. One of those is a device-private
> callback in the nouveau driver, the other is a generic wakeup needed in
> the DAX case. In the hopes that all ->page_free() callbacks can be
> migrated to common core kernel functionality, move the device-private
> specific actions in __put_devmap_managed_page() under the
> is_device_private_page() conditional, including the ->page_free()
> callback. For the other page types just open-code the generic wakeup.
>
> Yes, the wakeup is only needed in the MEMORY_DEVICE_FSDAX case, but it
> does no harm in the MEMORY_DEVICE_DEVDAX and MEMORY_DEVICE_PCI_P2PDMA
> case.
>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Jérôme Glisse <jglisse@redhat.com>
> Cc: John Hubbard <jhubbard@nvidia.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
> Hi John,
>
> This applies on top of today's linux-next and passes my nvdimm unit
> tests. That testing noticed that devmap_managed_enable_get() needed a
> small fixup as well.
Got it. This will appear in the next posted version of my "mm/gup: track
dma-pinned pages: FOLL_PIN, FOLL_LONGTERM" patchset.
>
> drivers/nvdimm/pmem.c | 6 ------
> mm/memremap.c | 22 ++++++++++++----------
> 2 files changed, 12 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
> index f9f76f6ba07b..21db1ce8c0ae 100644
> --- a/drivers/nvdimm/pmem.c
> +++ b/drivers/nvdimm/pmem.c
> @@ -338,13 +338,7 @@ static void pmem_release_disk(void *__pmem)
> put_disk(pmem->disk);
> }
>
> -static void pmem_pagemap_page_free(struct page *page)
> -{
> - wake_up_var(&page->_refcount);
> -}
> -
> static const struct dev_pagemap_ops fsdax_pagemap_ops = {
> - .page_free = pmem_pagemap_page_free,
> .kill = pmem_pagemap_kill,
> .cleanup = pmem_pagemap_cleanup,
> };
> diff --git a/mm/memremap.c b/mm/memremap.c
> index 022e78e68ea0..6e6f3d6fdb73 100644
> --- a/mm/memremap.c
> +++ b/mm/memremap.c
> @@ -27,7 +27,8 @@ static void devmap_managed_enable_put(void)
>
> static int devmap_managed_enable_get(struct dev_pagemap *pgmap)
> {
> - if (!pgmap->ops || !pgmap->ops->page_free) {
> + if (!pgmap->ops || (pgmap->type == MEMORY_DEVICE_PRIVATE
> + && !pgmap->ops->page_free)) {
OK, so only MEMORY_DEVICE_PRIVATE has .page_free ops. That looks
correct to me, based on looking at the .page_free setters--I
only see Nouveau setting it.
thanks,
--
John Hubbard
NVIDIA
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
next prev parent reply other threads:[~2019-11-14 0:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-14 0:07 [PATCH] mm: Cleanup __put_devmap_managed_page() vs ->page_free() Dan Williams
2019-11-14 0:39 ` John Hubbard [this message]
2019-11-14 0:47 ` Dan Williams
2019-11-14 7:23 ` Christoph Hellwig
2019-11-14 7:26 ` John Hubbard
2019-11-14 1:24 ` Jerome Glisse
2019-11-14 7:19 ` Christoph Hellwig
2019-11-14 7:25 ` Dan Williams
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=913133b7-58d8-9645-fc89-c2819825e1ee@nvidia.com \
--to=jhubbard@nvidia.com \
--cc=dan.j.williams@intel.com \
--cc=hch@lst.de \
--cc=jack@suse.cz \
--cc=jglisse@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nvdimm@lists.01.org \
/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).