From: peterx@redhat.com
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org,
Matthew Wilcox <willy@infradead.org>,
linuxppc-dev@lists.ozlabs.org,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Andrew Morton <akpm@linux-foundation.org>,
x86@kernel.org, peterx@redhat.com,
Mike Rapoport <rppt@kernel.org>,
Muchun Song <muchun.song@linux.dev>,
sparclinux@vger.kernel.org, Jason Gunthorpe <jgg@nvidia.com>,
Alistair Popple <apopple@nvidia.com>
Subject: [PATCH 01/13] mm/hmm: Process pud swap entry without pud_huge()
Date: Wed, 13 Mar 2024 17:47:07 -0400 [thread overview]
Message-ID: <20240313214719.253873-2-peterx@redhat.com> (raw)
In-Reply-To: <20240313214719.253873-1-peterx@redhat.com>
From: Peter Xu <peterx@redhat.com>
Swap pud entries do not always return true for pud_huge() for all archs.
x86 and sparc (so far) allow it, but all the rest do not accept a swap
entry to be reported as pud_huge(). So it's not safe to check swap entries
within pud_huge(). Check swap entries before pud_huge(), so it should be
always safe.
This is the only place in the kernel that (IMHO, wrongly) relies on
pud_huge() to return true on pud swap entries. The plan is to cleanup
pXd_huge() to only report non-swap mappings for all archs.
Cc: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
mm/hmm.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/mm/hmm.c b/mm/hmm.c
index 277ddcab4947..c95b9ec5d95f 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -424,7 +424,7 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
walk->action = ACTION_CONTINUE;
pud = READ_ONCE(*pudp);
- if (pud_none(pud)) {
+ if (!pud_present(pud)) {
spin_unlock(ptl);
return hmm_vma_walk_hole(start, end, -1, walk);
}
@@ -435,11 +435,6 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
unsigned long *hmm_pfns;
unsigned long cpu_flags;
- if (!pud_present(pud)) {
- spin_unlock(ptl);
- return hmm_vma_walk_hole(start, end, -1, walk);
- }
-
i = (addr - range->start) >> PAGE_SHIFT;
npages = (end - addr) >> PAGE_SHIFT;
hmm_pfns = &range->hmm_pfns[i];
--
2.44.0
WARNING: multiple messages have this Message-ID (diff)
From: peterx@redhat.com
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: Alistair Popple <apopple@nvidia.com>,
Muchun Song <muchun.song@linux.dev>,
Jason Gunthorpe <jgg@nvidia.com>,
x86@kernel.org, peterx@redhat.com,
Matthew Wilcox <willy@infradead.org>,
Mike Rapoport <rppt@kernel.org>,
sparclinux@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
linuxppc-dev@lists.ozlabs.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH 01/13] mm/hmm: Process pud swap entry without pud_huge()
Date: Wed, 13 Mar 2024 17:47:07 -0400 [thread overview]
Message-ID: <20240313214719.253873-2-peterx@redhat.com> (raw)
In-Reply-To: <20240313214719.253873-1-peterx@redhat.com>
From: Peter Xu <peterx@redhat.com>
Swap pud entries do not always return true for pud_huge() for all archs.
x86 and sparc (so far) allow it, but all the rest do not accept a swap
entry to be reported as pud_huge(). So it's not safe to check swap entries
within pud_huge(). Check swap entries before pud_huge(), so it should be
always safe.
This is the only place in the kernel that (IMHO, wrongly) relies on
pud_huge() to return true on pud swap entries. The plan is to cleanup
pXd_huge() to only report non-swap mappings for all archs.
Cc: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
mm/hmm.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/mm/hmm.c b/mm/hmm.c
index 277ddcab4947..c95b9ec5d95f 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -424,7 +424,7 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
walk->action = ACTION_CONTINUE;
pud = READ_ONCE(*pudp);
- if (pud_none(pud)) {
+ if (!pud_present(pud)) {
spin_unlock(ptl);
return hmm_vma_walk_hole(start, end, -1, walk);
}
@@ -435,11 +435,6 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
unsigned long *hmm_pfns;
unsigned long cpu_flags;
- if (!pud_present(pud)) {
- spin_unlock(ptl);
- return hmm_vma_walk_hole(start, end, -1, walk);
- }
-
i = (addr - range->start) >> PAGE_SHIFT;
npages = (end - addr) >> PAGE_SHIFT;
hmm_pfns = &range->hmm_pfns[i];
--
2.44.0
WARNING: multiple messages have this Message-ID (diff)
From: peterx@redhat.com
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org,
Matthew Wilcox <willy@infradead.org>,
linuxppc-dev@lists.ozlabs.org,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Andrew Morton <akpm@linux-foundation.org>,
x86@kernel.org, peterx@redhat.com,
Mike Rapoport <rppt@kernel.org>,
Muchun Song <muchun.song@linux.dev>,
sparclinux@vger.kernel.org, Jason Gunthorpe <jgg@nvidia.com>,
Alistair Popple <apopple@nvidia.com>
Subject: [PATCH 01/13] mm/hmm: Process pud swap entry without pud_huge()
Date: Wed, 13 Mar 2024 17:47:07 -0400 [thread overview]
Message-ID: <20240313214719.253873-2-peterx@redhat.com> (raw)
In-Reply-To: <20240313214719.253873-1-peterx@redhat.com>
From: Peter Xu <peterx@redhat.com>
Swap pud entries do not always return true for pud_huge() for all archs.
x86 and sparc (so far) allow it, but all the rest do not accept a swap
entry to be reported as pud_huge(). So it's not safe to check swap entries
within pud_huge(). Check swap entries before pud_huge(), so it should be
always safe.
This is the only place in the kernel that (IMHO, wrongly) relies on
pud_huge() to return true on pud swap entries. The plan is to cleanup
pXd_huge() to only report non-swap mappings for all archs.
Cc: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
mm/hmm.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/mm/hmm.c b/mm/hmm.c
index 277ddcab4947..c95b9ec5d95f 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -424,7 +424,7 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
walk->action = ACTION_CONTINUE;
pud = READ_ONCE(*pudp);
- if (pud_none(pud)) {
+ if (!pud_present(pud)) {
spin_unlock(ptl);
return hmm_vma_walk_hole(start, end, -1, walk);
}
@@ -435,11 +435,6 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
unsigned long *hmm_pfns;
unsigned long cpu_flags;
- if (!pud_present(pud)) {
- spin_unlock(ptl);
- return hmm_vma_walk_hole(start, end, -1, walk);
- }
-
i = (addr - range->start) >> PAGE_SHIFT;
npages = (end - addr) >> PAGE_SHIFT;
hmm_pfns = &range->hmm_pfns[i];
--
2.44.0
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-03-13 21:47 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-13 21:47 [PATCH 00/13] mm/treewide: Remove pXd_huge() API peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx [this message]
2024-03-13 21:47 ` [PATCH 01/13] mm/hmm: Process pud swap entry without pud_huge() peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` [PATCH 02/13] mm/gup: Cache p4d in follow_p4d_mask() peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` [PATCH 03/13] mm/gup: Check p4d presence before going on peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` [PATCH 04/13] mm/x86: Change pXd_huge() behavior to exclude swap entries peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` [PATCH 05/13] mm/sparc: " peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` [PATCH 06/13] mm/arm: Use macros to define pmd/pud helpers peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` [PATCH 07/13] mm/arm: Redefine pmd_huge() with pmd_leaf() peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` [PATCH 08/13] mm/arm64: Merge pXd_huge() and pXd_leaf() definitions peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` [PATCH 09/13] mm/powerpc: Redefine pXd_huge() with pXd_leaf() peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-14 8:45 ` Christophe Leroy
2024-03-14 8:45 ` Christophe Leroy
2024-03-14 8:45 ` Christophe Leroy
2024-03-14 12:53 ` Peter Xu
2024-03-14 12:53 ` Peter Xu
2024-03-14 12:53 ` Peter Xu
2024-03-14 13:11 ` Christophe Leroy
2024-03-14 13:11 ` Christophe Leroy
2024-03-14 13:11 ` Christophe Leroy
2024-03-18 16:15 ` Jason Gunthorpe
2024-03-18 16:15 ` Jason Gunthorpe
2024-03-18 16:15 ` Jason Gunthorpe
2024-03-19 23:07 ` Christophe Leroy
2024-03-19 23:07 ` Christophe Leroy
2024-03-19 23:07 ` Christophe Leroy
2024-03-19 23:26 ` Jason Gunthorpe
2024-03-19 23:26 ` Jason Gunthorpe
2024-03-19 23:26 ` Jason Gunthorpe
2024-03-20 6:16 ` Christophe Leroy
2024-03-20 6:16 ` Christophe Leroy
2024-03-20 6:16 ` Christophe Leroy
2024-03-20 16:09 ` Peter Xu
2024-03-20 16:09 ` Peter Xu
2024-03-20 16:09 ` Peter Xu
2024-03-20 17:40 ` Christophe Leroy
2024-03-20 17:40 ` Christophe Leroy
2024-03-20 17:40 ` Christophe Leroy
2024-03-20 20:24 ` Peter Xu
2024-03-20 20:24 ` Peter Xu
2024-03-20 20:24 ` Peter Xu
2024-03-13 21:47 ` [PATCH 10/13] mm/gup: Merge pXd huge mapping checks peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` [PATCH 11/13] mm/treewide: Replace pXd_huge() with pXd_leaf() peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-14 8:50 ` Christophe Leroy
2024-03-14 8:50 ` Christophe Leroy
2024-03-14 8:50 ` Christophe Leroy
2024-03-14 12:59 ` Peter Xu
2024-03-14 12:59 ` Peter Xu
2024-03-14 12:59 ` Peter Xu
2024-03-18 16:16 ` Jason Gunthorpe
2024-03-18 16:16 ` Jason Gunthorpe
2024-03-18 16:16 ` Jason Gunthorpe
2024-03-13 21:47 ` [PATCH 12/13] mm/treewide: Remove pXd_huge() peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
2024-03-14 8:56 ` Christophe Leroy
2024-03-14 8:56 ` Christophe Leroy
2024-03-14 8:56 ` Christophe Leroy
2024-03-14 14:08 ` Peter Xu
2024-03-14 14:08 ` Peter Xu
2024-03-14 14:08 ` Peter Xu
2024-03-13 21:47 ` [PATCH 13/13] mm: Document pXd_leaf() API peterx
2024-03-13 21:47 ` peterx
2024-03-13 21:47 ` peterx
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=20240313214719.253873-2-peterx@redhat.com \
--to=peterx@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=apopple@nvidia.com \
--cc=christophe.leroy@csgroup.eu \
--cc=jgg@nvidia.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=muchun.song@linux.dev \
--cc=rppt@kernel.org \
--cc=sparclinux@vger.kernel.org \
--cc=willy@infradead.org \
--cc=x86@kernel.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 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.