Andrew, since the previous patch
[PATCH 1/3] mm: add comment for __mod_zone_page_stat
is updated, update this one accordingly.
-----<8-----
>From 9701fbdb3f9e7730b89780a5bf22effd1580cf35 Mon Sep 17 00:00:00 2001
From: Jianyu Zhan <nasa4...@gmail.com>
Date: Tue, 13 May 2014 01:48:01 +0800
Subject: [PATCH] mm: fold mlocked_vma_newpage() into its only call site
In previous commit(mm: use the light version __mod_zone_page_state in
mlocked_vma_newpage()) a irq-unsafe __mod_zone_page_state is used.
And as suggested by Andrew, to reduce the risks that new call sites
incorrectly using mlocked_vma_newpage() without knowing they are adding
racing, this patch folds mlocked_vma_newpage() into its only call site,
page_add_new_anon_rmap, to make it open-cocded for people to know what
is going on.
Suggested-by: Andrew Morton <a...@linux-foundation.org>
Suggested-by: Hugh Dickins <hu...@google.com>
Signed-off-by: Jianyu Zhan <nasa4...@gmail.com>
---
mm/internal.h | 29 -----------------------------
mm/rmap.c | 20 +++++++++++++++++---
2 files changed, 17 insertions(+), 32 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index d6a4868..29f3dc8 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -184,31 +184,6 @@ static inline void munlock_vma_pages_all(struct
vm_area_struct *vma)
}
/*
- * Called only in fault path, to determine if a new page is being
- * mapped into a LOCKED vma. If it is, mark page as mlocked.
- */
-static inline int mlocked_vma_newpage(struct vm_area_struct *vma,
- struct page *page)
-{
- VM_BUG_ON_PAGE(PageLRU(page), page);
-
- if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
- return 0;
-
- if (!TestSetPageMlocked(page)) {
- /*
- * We use the irq-unsafe __mod_zone_page_stat because
- * this counter is not modified from interrupt context, and the
- * pte lock is held(spinlock), which implies preemption
disabled.
- */
- __mod_zone_page_state(page_zone(page), NR_MLOCK,
- hpage_nr_pages(page));
- count_vm_event(UNEVICTABLE_PGMLOCKED);
- }
- return 1;
-}
-
-/*
* must be called with vma's mmap_sem held for read or write, and page locked.
*/
extern void mlock_vma_page(struct page *page);
@@ -250,10 +225,6 @@ extern unsigned long vma_address(struct page *page,
struct vm_area_struct *vma);
#endif
#else /* !CONFIG_MMU */
-static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p)
-{
- return 0;
-}
static inline void clear_page_mlock(struct page *page) { }
static inline void mlock_vma_page(struct page *page) { }
static inline void mlock_migrate_page(struct page *new, struct page *old) { }
diff --git a/mm/rmap.c b/mm/rmap.c
index fa73194..386b78f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1029,11 +1029,25 @@ void page_add_new_anon_rmap(struct page *page,
__mod_zone_page_state(page_zone(page), NR_ANON_PAGES,
hpage_nr_pages(page));
__page_set_anon_rmap(page, vma, address, 1);
- if (!mlocked_vma_newpage(vma, page)) {
+
+ VM_BUG_ON_PAGE(PageLRU(page), page);
+ if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) {
SetPageActive(page);
lru_cache_add(page);
- } else
- add_page_to_unevictable_list(page);
+ return;
+ }
+
+ if (!TestSetPageMlocked(page)) {
+ /*
+ * We use the irq-unsafe __mod_zone_page_stat because
+ * this counter is not modified from interrupt context, and the
+ * pte lock is held(spinlock), which implies preemption
disabled.
+ */
+ __mod_zone_page_state(page_zone(page), NR_MLOCK,
+ hpage_nr_pages(page));
+ count_vm_event(UNEVICTABLE_PGMLOCKED);
+ }
+ add_page_to_unevictable_list(page);
}
/**
--
2.0.0-rc1
--
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