All of lore.kernel.org
 help / color / mirror / Atom feed
From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: DRI Development <dri-devel@lists.freedesktop.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	"Daniel Vetter" <daniel.vetter@ffwll.ch>,
	"Daniel Vetter" <daniel.vetter@intel.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"John Hubbard" <jhubbard@nvidia.com>,
	"Jérôme Glisse" <jglisse@redhat.com>, "Jan Kara" <jack@suse.cz>,
	"Dan Williams" <dan.j.williams@intel.com>,
	linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org
Subject: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM
Date: Fri,  2 Oct 2020 19:53:03 +0200	[thread overview]
Message-ID: <20201002175303.390363-2-daniel.vetter@ffwll.ch> (raw)
In-Reply-To: <20201002175303.390363-1-daniel.vetter@ffwll.ch>

For $reasons I've stumbled over this code and I'm not sure the change
to the new gup functions in 55a650c35fea ("mm/gup: frame_vector:
convert get_user_pages() --> pin_user_pages()") was entirely correct.

This here is used for long term buffers (not just quick I/O) like
RDMA, and John notes this in his patch. But I thought the rule for
these is that they need to add FOLL_LONGTERM, which John's patch
didn't do.

There is already a dax specific check (added in b7f0554a56f2 ("mm:
fail get_vaddr_frames() for filesystem-dax mappings")), so this seems
like the prudent thing to do.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-media@vger.kernel.org
---
Hi all,

I stumbled over this and figured typing this patch can't hurt. Really
just to maybe learn a few things about how gup/pup is supposed to be
used (we have a bit of that in drivers/gpu), this here isn't really
ralated to anything I'm doing.

I'm also wondering whether the explicit dax check should be removed,
since FOLL_LONGTERM should take care of that already.
-Daniel
---
 mm/frame_vector.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 5d34c9047e9c..3507e09cb3ff 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -35,7 +35,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
-	unsigned int gup_flags = FOLL_WRITE | FOLL_FORCE;
+	unsigned int gup_flags = FOLL_WRITE | FOLL_FORCE | FOLL_LONGTERM;
 	int ret = 0;
 	int err;
 	int locked;
-- 
2.28.0


WARNING: multiple messages have this Message-ID
From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: DRI Development <dri-devel@lists.freedesktop.org>
Cc: linux-samsung-soc@vger.kernel.org, "Jan Kara" <jack@suse.cz>,
	"Daniel Vetter" <daniel.vetter@ffwll.ch>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-mm@kvack.org, "Jérôme Glisse" <jglisse@redhat.com>,
	"John Hubbard" <jhubbard@nvidia.com>,
	"Daniel Vetter" <daniel.vetter@intel.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Dan Williams" <dan.j.williams@intel.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-media@vger.kernel.org
Subject: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM
Date: Fri,  2 Oct 2020 19:53:03 +0200	[thread overview]
Message-ID: <20201002175303.390363-2-daniel.vetter@ffwll.ch> (raw)
In-Reply-To: <20201002175303.390363-1-daniel.vetter@ffwll.ch>

For $reasons I've stumbled over this code and I'm not sure the change
to the new gup functions in 55a650c35fea ("mm/gup: frame_vector:
convert get_user_pages() --> pin_user_pages()") was entirely correct.

This here is used for long term buffers (not just quick I/O) like
RDMA, and John notes this in his patch. But I thought the rule for
these is that they need to add FOLL_LONGTERM, which John's patch
didn't do.

There is already a dax specific check (added in b7f0554a56f2 ("mm:
fail get_vaddr_frames() for filesystem-dax mappings")), so this seems
like the prudent thing to do.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-media@vger.kernel.org
---
Hi all,

I stumbled over this and figured typing this patch can't hurt. Really
just to maybe learn a few things about how gup/pup is supposed to be
used (we have a bit of that in drivers/gpu), this here isn't really
ralated to anything I'm doing.

I'm also wondering whether the explicit dax check should be removed,
since FOLL_LONGTERM should take care of that already.
-Daniel
---
 mm/frame_vector.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 5d34c9047e9c..3507e09cb3ff 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -35,7 +35,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
-	unsigned int gup_flags = FOLL_WRITE | FOLL_FORCE;
+	unsigned int gup_flags = FOLL_WRITE | FOLL_FORCE | FOLL_LONGTERM;
 	int ret = 0;
 	int err;
 	int locked;
-- 
2.28.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID
From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: DRI Development <dri-devel@lists.freedesktop.org>
Cc: linux-samsung-soc@vger.kernel.org, "Jan Kara" <jack@suse.cz>,
	"Daniel Vetter" <daniel.vetter@ffwll.ch>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-mm@kvack.org, "Jérôme Glisse" <jglisse@redhat.com>,
	"John Hubbard" <jhubbard@nvidia.com>,
	"Daniel Vetter" <daniel.vetter@intel.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Dan Williams" <dan.j.williams@intel.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-media@vger.kernel.org
Subject: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM
Date: Fri,  2 Oct 2020 19:53:03 +0200	[thread overview]
Message-ID: <20201002175303.390363-2-daniel.vetter@ffwll.ch> (raw)
In-Reply-To: <20201002175303.390363-1-daniel.vetter@ffwll.ch>

For $reasons I've stumbled over this code and I'm not sure the change
to the new gup functions in 55a650c35fea ("mm/gup: frame_vector:
convert get_user_pages() --> pin_user_pages()") was entirely correct.

This here is used for long term buffers (not just quick I/O) like
RDMA, and John notes this in his patch. But I thought the rule for
these is that they need to add FOLL_LONGTERM, which John's patch
didn't do.

There is already a dax specific check (added in b7f0554a56f2 ("mm:
fail get_vaddr_frames() for filesystem-dax mappings")), so this seems
like the prudent thing to do.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-media@vger.kernel.org
---
Hi all,

I stumbled over this and figured typing this patch can't hurt. Really
just to maybe learn a few things about how gup/pup is supposed to be
used (we have a bit of that in drivers/gpu), this here isn't really
ralated to anything I'm doing.

I'm also wondering whether the explicit dax check should be removed,
since FOLL_LONGTERM should take care of that already.
-Daniel
---
 mm/frame_vector.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 5d34c9047e9c..3507e09cb3ff 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -35,7 +35,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
-	unsigned int gup_flags = FOLL_WRITE | FOLL_FORCE;
+	unsigned int gup_flags = FOLL_WRITE | FOLL_FORCE | FOLL_LONGTERM;
 	int ret = 0;
 	int err;
 	int locked;
-- 
2.28.0

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  reply	other threads:[~2020-10-02 17:53 UTC|newest]

Thread overview: 156+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-02 17:53 [PATCH 1/2] mm/frame-vec: Drop gup_flags from get_vaddr_frames() Daniel Vetter
2020-10-02 17:53 ` Daniel Vetter [this message]
2020-10-02 18:06   ` [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM Jason Gunthorpe
2020-10-02 18:16     ` Daniel Vetter
2020-10-02 23:31       ` Jason Gunthorpe
2020-10-03  8:34         ` Oded Gabbay
2020-10-03  9:40         ` Daniel Vetter
2020-10-04 12:50           ` Jason Gunthorpe
2020-10-04 16:09             ` Daniel Vetter
2020-10-05 17:28               ` Jason Gunthorpe
2020-10-05 18:16                 ` Daniel Vetter
2020-10-05 18:37                   ` Jason Gunthorpe
2020-10-05 18:54                     ` Daniel Vetter
2020-10-05 22:43                       ` Daniel Vetter
2020-10-05 23:41                         ` Jason Gunthorpe
2020-10-06  6:23                           ` Daniel Vetter
2020-10-06 12:26                             ` Jason Gunthorpe
2020-10-06 13:08                               ` Daniel Vetter
2020-10-07 10:47           ` Marek Szyprowski
2020-10-07 12:01             ` Daniel Vetter
2020-10-07 12:33               ` Marek Szyprowski
2020-10-07 12:44                 ` Jason Gunthorpe
2020-10-07 12:47                   ` Tomasz Figa
2020-10-07 12:58                     ` Daniel Vetter
2020-10-07 13:06                       ` Jason Gunthorpe
2020-10-07 13:34                         ` Tomasz Figa
2020-10-07 13:42                           ` Jason Gunthorpe
2020-10-07 14:08                           ` Daniel Vetter
2020-10-07 14:11                             ` Tomasz Figa
2020-10-07 14:22                               ` Daniel Vetter
2020-10-07 15:05                                 ` Tomasz Figa
2020-10-07 14:58                               ` Jason Gunthorpe
2020-10-07 13:06         ` Tomasz Figa
2020-10-07 13:14           ` Jason Gunthorpe
2020-10-05 15:03     ` Jan Kara
2020-10-02 22:39   ` John Hubbard
2020-10-03  9:45     ` Daniel Vetter
2020-10-03 22:52       ` John Hubbard
2020-10-03 23:24         ` Jason Gunthorpe
2020-10-04 11:20           ` Daniel Vetter
2020-10-05 17:35             ` Jason Gunthorpe
2020-10-02 18:22 ` [PATCH 1/2] mm/frame-vec: Drop gup_flags from get_vaddr_frames() Tomasz Figa
2020-10-02 19:21   ` Oded Gabbay
2020-10-05 17:38 [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM Jason Gunthorpe
2020-10-05 17:47 ` Jason Gunthorpe
2020-10-06  3:36   ` Andrew Morton
2020-10-06 11:57     ` Jason Gunthorpe
2020-10-05 17:53 ` Jan Kara
2020-10-05 17:57   ` Jason Gunthorpe
2020-10-05 18:16     ` Daniel Vetter
2020-10-06 11:56     ` Daniel Vetter

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=20201002175303.390363-2-daniel.vetter@ffwll.ch \
    --to=daniel.vetter@ffwll.ch \
    --cc=akpm@linux-foundation.org \
    --cc=dan.j.williams@intel.com \
    --cc=daniel.vetter@intel.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=jack@suse.cz \
    --cc=jglisse@redhat.com \
    --cc=jhubbard@nvidia.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-samsung-soc@vger.kernel.org \
    --subject='Re: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM' \
    /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

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.