From: Khalid Aziz <khalid.aziz@oracle.com>
To: akpm@linux-foundation.org, willy@infradead.org
Cc: Khalid Aziz <khalid.aziz@oracle.com>,
aneesh.kumar@linux.ibm.com, arnd@arndb.de, 21cnbao@gmail.com,
corbet@lwn.net, dave.hansen@linux.intel.com, david@redhat.com,
ebiederm@xmission.com, hagen@jauu.net, jack@suse.cz,
keescook@chromium.org, kirill@shutemov.name, kucharsk@gmail.com,
linkinjeon@kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
longpeng2@huawei.com, luto@kernel.org, markhemm@googlemail.com,
pcc@google.com, rppt@kernel.org, sieberf@amazon.com,
sjpark@amazon.de, surenb@google.com, tst@schoebel-theuer.de,
yzaikin@google.com
Subject: [PATCH v1 07/14] mm/mshare: Add vm flag for shared PTE
Date: Mon, 11 Apr 2022 10:05:51 -0600 [thread overview]
Message-ID: <4ee9ab4d46669c40ab3c42e97774ffab85db5662.1649370874.git.khalid.aziz@oracle.com> (raw)
In-Reply-To: <cover.1649370874.git.khalid.aziz@oracle.com>
Add a bit to vm_flags to indicate a vma shares PTEs with others. Add
a function to determine if a vma shares PTE by checking this flag.
This is to be used to find the shared page table entries on page fault
for vmas sharing PTE.
Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
include/linux/mm.h | 8 ++++++++
include/trace/events/mmflags.h | 3 ++-
mm/internal.h | 5 +++++
3 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5744a3fc4716..821ed7ee7b41 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -308,11 +308,13 @@ extern unsigned int kobjsize(const void *objp);
#define VM_HIGH_ARCH_BIT_2 34 /* bit only usable on 64-bit architectures */
#define VM_HIGH_ARCH_BIT_3 35 /* bit only usable on 64-bit architectures */
#define VM_HIGH_ARCH_BIT_4 36 /* bit only usable on 64-bit architectures */
+#define VM_HIGH_ARCH_BIT_5 37 /* bit only usable on 64-bit architectures */
#define VM_HIGH_ARCH_0 BIT(VM_HIGH_ARCH_BIT_0)
#define VM_HIGH_ARCH_1 BIT(VM_HIGH_ARCH_BIT_1)
#define VM_HIGH_ARCH_2 BIT(VM_HIGH_ARCH_BIT_2)
#define VM_HIGH_ARCH_3 BIT(VM_HIGH_ARCH_BIT_3)
#define VM_HIGH_ARCH_4 BIT(VM_HIGH_ARCH_BIT_4)
+#define VM_HIGH_ARCH_5 BIT(VM_HIGH_ARCH_BIT_5)
#endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */
#ifdef CONFIG_ARCH_HAS_PKEYS
@@ -354,6 +356,12 @@ extern unsigned int kobjsize(const void *objp);
# define VM_MTE_ALLOWED VM_NONE
#endif
+#ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
+#define VM_SHARED_PT VM_HIGH_ARCH_5
+#else
+#define VM_SHARED_PT 0
+#endif
+
#ifndef VM_GROWSUP
# define VM_GROWSUP VM_NONE
#endif
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 116ed4d5d0f8..002dbf2711c5 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -184,7 +184,8 @@ IF_HAVE_VM_SOFTDIRTY(VM_SOFTDIRTY, "softdirty" ) \
{VM_MIXEDMAP, "mixedmap" }, \
{VM_HUGEPAGE, "hugepage" }, \
{VM_NOHUGEPAGE, "nohugepage" }, \
- {VM_MERGEABLE, "mergeable" } \
+ {VM_MERGEABLE, "mergeable" }, \
+ {VM_SHARED_PT, "sharedpt" } \
#define show_vma_flags(flags) \
(flags) ? __print_flags(flags, "|", \
diff --git a/mm/internal.h b/mm/internal.h
index d80300392a19..cf50a471384e 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -718,4 +718,9 @@ void vunmap_range_noflush(unsigned long start, unsigned long end);
int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
unsigned long addr, int page_nid, int *flags);
+static inline bool vma_is_shared(const struct vm_area_struct *vma)
+{
+ return vma->vm_flags & VM_SHARED_PT;
+}
+
#endif /* __MM_INTERNAL_H */
--
2.32.0
next prev parent reply other threads:[~2022-04-11 16:07 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-11 16:05 [PATCH v1 00/14] Add support for shared PTEs across processes Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 01/14] mm: Add new system calls mshare, mshare_unlink Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 02/14] mm/mshare: Add msharefs filesystem Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 03/14] mm/mshare: Add read for msharefs Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 04/14] mm/mshare: implement mshare_unlink syscall Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 05/14] mm/mshare: Add locking to msharefs syscalls Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 06/14] mm/mshare: Check for mounted filesystem Khalid Aziz
2022-04-11 16:05 ` Khalid Aziz [this message]
2022-04-11 16:05 ` [PATCH v1 08/14] mm/mshare: Add basic page table sharing using mshare Khalid Aziz
2022-04-11 18:48 ` Dave Hansen
2022-04-11 20:39 ` Khalid Aziz
2022-05-30 11:11 ` Barry Song
2022-06-28 20:11 ` Khalid Aziz
2022-05-31 3:46 ` Barry Song
2022-06-28 20:16 ` Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 09/14] mm/mshare: Do not free PTEs for mshare'd PTEs Khalid Aziz
2022-05-31 4:24 ` Barry Song
2022-06-29 17:38 ` Khalid Aziz
2022-07-03 20:54 ` Andy Lutomirski
2022-07-06 20:33 ` Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 10/14] mm/mshare: Check for mapped vma when mshare'ing existing mshare'd range Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 11/14] mm/mshare: unmap vmas in mshare_unlink Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 12/14] mm/mshare: Add a proc file with mshare alignment/size information Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 13/14] mm/mshare: Enforce mshare'd region permissions Khalid Aziz
2022-04-11 16:05 ` [PATCH v1 14/14] mm/mshare: Copy PTEs to host mm Khalid Aziz
2022-04-11 17:37 ` [PATCH v1 00/14] Add support for shared PTEs across processes Matthew Wilcox
2022-04-11 18:51 ` Dave Hansen
2022-04-11 19:08 ` Matthew Wilcox
2022-04-11 19:52 ` Khalid Aziz
2022-04-11 18:47 ` Dave Hansen
2022-04-11 20:10 ` Eric W. Biederman
2022-04-11 22:21 ` Khalid Aziz
2022-05-30 10:48 ` Barry Song
2022-05-30 11:18 ` David Hildenbrand
2022-05-30 11:49 ` Barry Song
2022-06-29 17:48 ` Khalid Aziz
2022-06-29 17:40 ` Khalid Aziz
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