[PATCH v4 6/7] Remove zap_details NULL dependency

From: Minchan Kim
Date: Sun Dec 05 2010 - 12:30:56 EST


Some functions used zap_details depends on assumption that
zap_details parameter should be NULLed if some fields are 0.

This patch removes that dependency for next patch easy review/merge.
It should not chanage behavior.

Signed-off-by: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
---
include/linux/mm.h | 8 ++++++++
mm/madvise.c | 15 +++++++++------
mm/memory.c | 14 ++++++++------
mm/mmap.c | 6 ++++--
4 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index e097df6..6522ae4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -773,6 +773,14 @@ struct zap_details {
unsigned long truncate_count; /* Compare vm_truncate_count */
};

+#define __ZAP_DETAILS_INITIALIZER(name) \
+ { .nonlinear_vma = NULL \
+ , .check_mapping = NULL \
+ , .i_mmap_lock = NULL }
+
+#define DEFINE_ZAP_DETAILS(name) \
+ struct zap_details name = __ZAP_DETAILS_INITIALIZER(name)
+
struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
pte_t pte);

diff --git a/mm/madvise.c b/mm/madvise.c
index 319528b..bfa17aa 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -162,18 +162,21 @@ static long madvise_dontneed(struct vm_area_struct * vma,
struct vm_area_struct ** prev,
unsigned long start, unsigned long end)
{
+ DEFINE_ZAP_DETAILS(details);
+
*prev = vma;
if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
return -EINVAL;

if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
- struct zap_details details = {
- .nonlinear_vma = vma,
- .last_index = ULONG_MAX,
- };
+ details.nonlinear_vma = vma;
+ details.last_index = ULONG_MAX;
+
zap_page_range(vma, start, end - start, &details);
- } else
- zap_page_range(vma, start, end - start, NULL);
+ } else {
+
+ zap_page_range(vma, start, end - start, &details);
+ }
return 0;
}

diff --git a/mm/memory.c b/mm/memory.c
index ebfeedf..c0879bb 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -900,6 +900,9 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,

init_rss_vec(rss);

+ if (!details->check_mapping && !details->nonlinear_vma)
+ details = NULL;
+
pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
arch_enter_lazy_mmu_mode();
do {
@@ -1038,9 +1041,6 @@ static unsigned long unmap_page_range(struct mmu_gather *tlb,
pgd_t *pgd;
unsigned long next;

- if (details && !details->check_mapping && !details->nonlinear_vma)
- details = NULL;
-
BUG_ON(addr >= end);
mem_cgroup_uncharge_start();
tlb_start_vma(tlb, vma);
@@ -1102,7 +1102,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
unsigned long tlb_start = 0; /* For tlb_finish_mmu */
int tlb_start_valid = 0;
unsigned long start = start_addr;
- spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL;
+ spinlock_t *i_mmap_lock = details->i_mmap_lock;
int fullmm = (*tlbp)->fullmm;
struct mm_struct *mm = vma->vm_mm;

@@ -1217,10 +1217,11 @@ unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
unsigned long size)
{
+ DEFINE_ZAP_DETAILS(details);
if (address < vma->vm_start || address + size > vma->vm_end ||
!(vma->vm_flags & VM_PFNMAP))
return -1;
- zap_page_range(vma, address, size, NULL);
+ zap_page_range(vma, address, size, &details);
return 0;
}
EXPORT_SYMBOL_GPL(zap_vma_ptes);
@@ -2577,7 +2578,8 @@ restart:
void unmap_mapping_range(struct address_space *mapping,
loff_t const holebegin, loff_t const holelen, int even_cows)
{
- struct zap_details details;
+ DEFINE_ZAP_DETAILS(details);
+
pgoff_t hba = holebegin >> PAGE_SHIFT;
pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT;

diff --git a/mm/mmap.c b/mm/mmap.c
index b179abb..31d2594 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1900,11 +1900,12 @@ static void unmap_region(struct mm_struct *mm,
struct vm_area_struct *next = prev? prev->vm_next: mm->mmap;
struct mmu_gather *tlb;
unsigned long nr_accounted = 0;
+ DEFINE_ZAP_DETAILS(details);

lru_add_drain();
tlb = tlb_gather_mmu(mm, 0);
update_hiwater_rss(mm);
- unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL);
+ unmap_vmas(&tlb, vma, start, end, &nr_accounted, &details);
vm_unacct_memory(nr_accounted);
free_pgtables(tlb, vma, prev? prev->vm_end: FIRST_USER_ADDRESS,
next? next->vm_start: 0);
@@ -2254,6 +2255,7 @@ void exit_mmap(struct mm_struct *mm)
struct vm_area_struct *vma;
unsigned long nr_accounted = 0;
unsigned long end;
+ DEFINE_ZAP_DETAILS(details);

/* mm's last user has gone, and its about to be pulled down */
mmu_notifier_release(mm);
@@ -2278,7 +2280,7 @@ void exit_mmap(struct mm_struct *mm)
tlb = tlb_gather_mmu(mm, 1);
/* update_hiwater_rss(mm) here? but nobody should be looking */
/* Use -1 here to ensure all VMAs in the mm are unmapped */
- end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
+ end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, &details);
vm_unacct_memory(nr_accounted);

free_pgtables(tlb, vma, FIRST_USER_ADDRESS, 0);
--
1.7.0.4

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