From: Jason Gunthorpe <jgg@ziepe.ca>
To: john.hubbard@gmail.com
Cc: Matthew Wilcox <willy@infradead.org>,
Michal Hocko <mhocko@kernel.org>,
Christopher Lameter <cl@linux.com>,
Dan Williams <dan.j.williams@intel.com>, Jan Kara <jack@suse.cz>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
linux-rdma <linux-rdma@vger.kernel.org>,
linux-fsdevel@vger.kernel.org, John Hubbard <jhubbard@nvidia.com>,
Doug Ledford <dledford@redhat.com>,
Mike Marciniszyn <mike.marciniszyn@intel.com>,
Dennis Dalessandro <dennis.dalessandro@intel.com>,
Christian Benvenuti <benve@cisco.com>
Subject: Re: [PATCH v2 3/3] infiniband/mm: convert to the new put_user_page[s]() calls
Date: Fri, 5 Oct 2018 09:20:55 -0600 [thread overview]
Message-ID: <20181005152055.GB20776@ziepe.ca> (raw)
In-Reply-To: <20181005040225.14292-4-jhubbard@nvidia.com>
On Thu, Oct 04, 2018 at 09:02:25PM -0700, john.hubbard@gmail.com wrote:
> From: John Hubbard <jhubbard@nvidia.com>
>
> For code that retains pages via get_user_pages*(),
> release those pages via the new put_user_page(),
> instead of put_page().
>
> This prepares for eventually fixing the problem described
> in [1], and is following a plan listed in [2], [3], [4].
>
> [1] https://lwn.net/Articles/753027/ : "The Trouble with get_user_pages()"
>
> [2] https://lkml.kernel.org/r/20180709080554.21931-1-jhubbard@nvidia.com
> Proposed steps for fixing get_user_pages() + DMA problems.
>
> [3]https://lkml.kernel.org/r/20180710082100.mkdwngdv5kkrcz6n@quack2.suse.cz
> Bounce buffers (otherwise [2] is not really viable).
>
> [4] https://lkml.kernel.org/r/20181003162115.GG24030@quack2.suse.cz
> Follow-up discussions.
>
> CC: Doug Ledford <dledford@redhat.com>
> CC: Jason Gunthorpe <jgg@ziepe.ca>
> CC: Mike Marciniszyn <mike.marciniszyn@intel.com>
> CC: Dennis Dalessandro <dennis.dalessandro@intel.com>
> CC: Christian Benvenuti <benve@cisco.com>
>
> CC: linux-rdma@vger.kernel.org
> CC: linux-kernel@vger.kernel.org
> CC: linux-mm@kvack.org
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> drivers/infiniband/core/umem.c | 2 +-
> drivers/infiniband/core/umem_odp.c | 2 +-
> drivers/infiniband/hw/hfi1/user_pages.c | 11 ++++-------
> drivers/infiniband/hw/mthca/mthca_memfree.c | 6 +++---
> drivers/infiniband/hw/qib/qib_user_pages.c | 11 ++++-------
> drivers/infiniband/hw/qib/qib_user_sdma.c | 8 ++++----
> drivers/infiniband/hw/usnic/usnic_uiom.c | 2 +-
> 7 files changed, 18 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> index a41792dbae1f..9430d697cb9f 100644
> +++ b/drivers/infiniband/core/umem.c
> @@ -60,7 +60,7 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d
> page = sg_page(sg);
> if (!PageDirty(page) && umem->writable && dirty)
> set_page_dirty_lock(page);
> - put_page(page);
> + put_user_page(page);
> }
How about ?
if (umem->writable && dirty)
put_user_pages_dirty_lock(&page, 1);
else
put_user_page(page);
?
> diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c
> index e341e6dcc388..99ccc0483711 100644
> +++ b/drivers/infiniband/hw/hfi1/user_pages.c
> @@ -121,13 +121,10 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t np
> void hfi1_release_user_pages(struct mm_struct *mm, struct page **p,
> size_t npages, bool dirty)
> {
> - size_t i;
> -
> - for (i = 0; i < npages; i++) {
> - if (dirty)
> - set_page_dirty_lock(p[i]);
> - put_page(p[i]);
> - }
> + if (dirty)
> + put_user_pages_dirty_lock(p, npages);
> + else
> + put_user_pages(p, npages);
And I know Jan gave the feedback to remove the bool argument, but just
pointing out that quite possibly evey caller will wrapper it in an if
like this..
Jason
next prev parent reply other threads:[~2018-10-05 15:20 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-05 4:02 [PATCH v2 0/3] get_user_pages*() and RDMA: first steps john.hubbard
2018-10-05 4:02 ` [PATCH v2 1/3] mm: get_user_pages: consolidate error handling john.hubbard
2018-10-05 4:02 ` [PATCH v2 2/3] mm: introduce put_user_page[s](), placeholder versions john.hubbard
2018-10-05 15:17 ` Jason Gunthorpe
2018-10-05 19:49 ` John Hubbard
2018-10-05 20:51 ` John Hubbard
2018-10-05 21:48 ` Jason Gunthorpe
2018-10-06 0:03 ` John Hubbard
2018-10-05 4:02 ` [PATCH v2 3/3] infiniband/mm: convert to the new put_user_page[s]() calls john.hubbard
2018-10-05 15:20 ` Jason Gunthorpe [this message]
2018-10-05 20:48 ` John Hubbard
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=20181005152055.GB20776@ziepe.ca \
--to=jgg@ziepe.ca \
--cc=benve@cisco.com \
--cc=cl@linux.com \
--cc=dan.j.williams@intel.com \
--cc=dennis.dalessandro@intel.com \
--cc=dledford@redhat.com \
--cc=jack@suse.cz \
--cc=jhubbard@nvidia.com \
--cc=john.hubbard@gmail.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-rdma@vger.kernel.org \
--cc=mhocko@kernel.org \
--cc=mike.marciniszyn@intel.com \
--cc=willy@infradead.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).