From: Laurent Dufour <ldufour@linux.vnet.ibm.com>
To: paulmck@linux.vnet.ibm.com, peterz@infradead.org,
akpm@linux-foundation.org, kirill@shutemov.name,
ak@linux.intel.com, mhocko@kernel.org, dave@stgolabs.net,
jack@suse.cz, Matthew Wilcox <willy@infradead.org>,
benh@kernel.crashing.org, mpe@ellerman.id.au, paulus@samba.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
hpa@zytor.com, Will Deacon <will.deacon@arm.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com,
npiggin@gmail.com, bsingharora@gmail.com,
Tim Chen <tim.c.chen@linux.intel.com>,
linuxppc-dev@lists.ozlabs.org, x86@kernel.org
Subject: [PATCH v3 11/20] mm: Introduce __maybe_mkwrite()
Date: Fri, 8 Sep 2017 20:06:55 +0200 [thread overview]
Message-ID: <1504894024-2750-12-git-send-email-ldufour@linux.vnet.ibm.com> (raw)
In-Reply-To: <1504894024-2750-1-git-send-email-ldufour@linux.vnet.ibm.com>
The current maybe_mkwrite() is getting passed the pointer to the vma
structure to fetch the vm_flags field.
When dealing with the speculative page fault handler, it will be better to
rely on the cached vm_flags value stored in the vm_fault structure.
This patch introduce a __maybe_mkwrite() service which can be called by
passing the value of the vm_flags field.
There is no change functional changes expected for the other callers of
maybe_mkwrite().
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
include/linux/mm.h | 9 +++++++--
mm/memory.c | 6 +++---
2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5fd90ac31317..bb0c87f1c725 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -673,13 +673,18 @@ void free_compound_page(struct page *page);
* pte_mkwrite. But get_user_pages can cause write faults for mappings
* that do not have writing enabled, when used by access_process_vm.
*/
-static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
+static inline pte_t __maybe_mkwrite(pte_t pte, unsigned long vma_flags)
{
- if (likely(vma->vm_flags & VM_WRITE))
+ if (likely(vma_flags & VM_WRITE))
pte = pte_mkwrite(pte);
return pte;
}
+static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
+{
+ return __maybe_mkwrite(pte, vma->vm_flags);
+}
+
int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
struct page *page);
int finish_fault(struct vm_fault *vmf);
diff --git a/mm/memory.c b/mm/memory.c
index 4583f354be94..c306f1f64c9e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2408,7 +2408,7 @@ static inline void wp_page_reuse(struct vm_fault *vmf)
flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte));
entry = pte_mkyoung(vmf->orig_pte);
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ entry = __maybe_mkwrite(pte_mkdirty(entry), vmf->vma_flags);
if (ptep_set_access_flags(vma, vmf->address, vmf->pte, entry, 1))
update_mmu_cache(vma, vmf->address, vmf->pte);
pte_unmap_unlock(vmf->pte, vmf->ptl);
@@ -2498,8 +2498,8 @@ static int wp_page_copy(struct vm_fault *vmf)
inc_mm_counter_fast(mm, MM_ANONPAGES);
}
flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte));
- entry = mk_pte(new_page, vma->vm_page_prot);
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ entry = mk_pte(new_page, vmf->vma_page_prot);
+ entry = __maybe_mkwrite(pte_mkdirty(entry), vmf->vma_flags);
/*
* Clear the pte entry and flush it first, before updating the
* pte with the new entry. This will avoid a race condition
--
2.7.4
next prev parent reply other threads:[~2017-09-08 18:07 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-08 18:06 [PATCH v3 00/20] Speculative page faults Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 01/20] mm: Dont assume page-table invariance during faults Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 02/20] mm: Prepare for FAULT_FLAG_SPECULATIVE Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 03/20] mm: Introduce pte_spinlock " Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 04/20] mm: VMA sequence count Laurent Dufour
2017-09-13 11:53 ` Sergey Senozhatsky
2017-09-13 16:56 ` Laurent Dufour
2017-09-14 0:31 ` Sergey Senozhatsky
2017-09-14 7:55 ` Laurent Dufour
2017-09-14 8:13 ` Sergey Senozhatsky
2017-09-14 8:58 ` Laurent Dufour
2017-09-14 9:11 ` Sergey Senozhatsky
2017-09-14 9:15 ` Laurent Dufour
2017-09-14 9:40 ` Sergey Senozhatsky
2017-09-15 12:38 ` Laurent Dufour
2017-09-25 12:22 ` Peter Zijlstra
2017-09-08 18:06 ` [PATCH v3 05/20] mm: Protect VMA modifications using " Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 06/20] mm: RCU free VMAs Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 07/20] mm: Cache some VMA fields in the vm_fault structure Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 08/20] mm: Protect SPF handler against anon_vma changes Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 09/20] mm/migrate: Pass vm_fault pointer to migrate_misplaced_page() Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 10/20] mm: Introduce __lru_cache_add_active_or_unevictable Laurent Dufour
2017-09-08 18:06 ` Laurent Dufour [this message]
2017-09-08 18:06 ` [PATCH v3 12/20] mm: Introduce __vm_normal_page() Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 13/20] mm: Introduce __page_add_new_anon_rmap() Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 14/20] mm: Provide speculative fault infrastructure Laurent Dufour
2017-09-08 18:06 ` [PATCH v3 15/20] mm: Try spin lock in speculative path Laurent Dufour
2017-09-08 18:07 ` [PATCH v3 16/20] mm: Adding speculative page fault failure trace events Laurent Dufour
2017-09-08 18:07 ` [PATCH v3 17/20] perf: Add a speculative page fault sw event Laurent Dufour
2017-09-08 18:07 ` [PATCH v3 18/20] perf tools: Add support for the SPF perf event Laurent Dufour
2017-09-08 18:07 ` [PATCH v3 19/20] x86/mm: Add speculative pagefault handling Laurent Dufour
2017-09-08 18:07 ` [PATCH v3 20/20] powerpc/mm: Add speculative page fault Laurent Dufour
2017-09-18 7:15 ` [PATCH v3 00/20] Speculative page faults Laurent Dufour
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