pagewalk: separate function pointers from iterator data
The mm_walk structure currently mixed data and code. Split out the
operations vectors into a new mm_walk_ops structure, and while we are
changing the API also declare the mm_walk structure inside the
walk_page_range and walk_page_vma functions.
Based on patch from Linus Torvalds.
Link: https://lore.kernel.org/r/20190828141955.22210-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 8857da8..bf43d1d 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -513,7 +513,9 @@ static int smaps_pte_hole(unsigned long addr, unsigned long end,
return 0;
}
-#endif
+#else
+#define smaps_pte_hole NULL
+#endif /* CONFIG_SHMEM */
static void smaps_pte_entry(pte_t *pte, unsigned long addr,
struct mm_walk *walk)
@@ -729,21 +731,24 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
}
return 0;
}
+#else
+#define smaps_hugetlb_range NULL
#endif /* HUGETLB_PAGE */
+static const struct mm_walk_ops smaps_walk_ops = {
+ .pmd_entry = smaps_pte_range,
+ .hugetlb_entry = smaps_hugetlb_range,
+};
+
+static const struct mm_walk_ops smaps_shmem_walk_ops = {
+ .pmd_entry = smaps_pte_range,
+ .hugetlb_entry = smaps_hugetlb_range,
+ .pte_hole = smaps_pte_hole,
+};
+
static void smap_gather_stats(struct vm_area_struct *vma,
struct mem_size_stats *mss)
{
- struct mm_walk smaps_walk = {
- .pmd_entry = smaps_pte_range,
-#ifdef CONFIG_HUGETLB_PAGE
- .hugetlb_entry = smaps_hugetlb_range,
-#endif
- .mm = vma->vm_mm,
- };
-
- smaps_walk.private = mss;
-
#ifdef CONFIG_SHMEM
/* In case of smaps_rollup, reset the value from previous vma */
mss->check_shmem_swap = false;
@@ -765,12 +770,13 @@ static void smap_gather_stats(struct vm_area_struct *vma,
mss->swap += shmem_swapped;
} else {
mss->check_shmem_swap = true;
- smaps_walk.pte_hole = smaps_pte_hole;
+ walk_page_vma(vma, &smaps_shmem_walk_ops, mss);
+ return;
}
}
#endif
/* mmap_sem is held in m_start */
- walk_page_vma(vma, &smaps_walk);
+ walk_page_vma(vma, &smaps_walk_ops, mss);
}
#define SEQ_PUT_DEC(str, val) \
@@ -1118,6 +1124,11 @@ static int clear_refs_test_walk(unsigned long start, unsigned long end,
return 0;
}
+static const struct mm_walk_ops clear_refs_walk_ops = {
+ .pmd_entry = clear_refs_pte_range,
+ .test_walk = clear_refs_test_walk,
+};
+
static ssize_t clear_refs_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
@@ -1151,12 +1162,6 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
struct clear_refs_private cp = {
.type = type,
};
- struct mm_walk clear_refs_walk = {
- .pmd_entry = clear_refs_pte_range,
- .test_walk = clear_refs_test_walk,
- .mm = mm,
- .private = &cp,
- };
if (type == CLEAR_REFS_MM_HIWATER_RSS) {
if (down_write_killable(&mm->mmap_sem)) {
@@ -1217,7 +1222,8 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
0, NULL, mm, 0, -1UL);
mmu_notifier_invalidate_range_start(&range);
}
- walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
+ walk_page_range(mm, 0, mm->highest_vm_end, &clear_refs_walk_ops,
+ &cp);
if (type == CLEAR_REFS_SOFT_DIRTY)
mmu_notifier_invalidate_range_end(&range);
tlb_finish_mmu(&tlb, 0, -1);
@@ -1489,8 +1495,16 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
return err;
}
+#else
+#define pagemap_hugetlb_range NULL
#endif /* HUGETLB_PAGE */
+static const struct mm_walk_ops pagemap_ops = {
+ .pmd_entry = pagemap_pmd_range,
+ .pte_hole = pagemap_pte_hole,
+ .hugetlb_entry = pagemap_hugetlb_range,
+};
+
/*
* /proc/pid/pagemap - an array mapping virtual pages to pfns
*
@@ -1522,7 +1536,6 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
{
struct mm_struct *mm = file->private_data;
struct pagemapread pm;
- struct mm_walk pagemap_walk = {};
unsigned long src;
unsigned long svpfn;
unsigned long start_vaddr;
@@ -1550,14 +1563,6 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
if (!pm.buffer)
goto out_mm;
- pagemap_walk.pmd_entry = pagemap_pmd_range;
- pagemap_walk.pte_hole = pagemap_pte_hole;
-#ifdef CONFIG_HUGETLB_PAGE
- pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
-#endif
- pagemap_walk.mm = mm;
- pagemap_walk.private = ±
-
src = *ppos;
svpfn = src / PM_ENTRY_BYTES;
start_vaddr = svpfn << PAGE_SHIFT;
@@ -1586,7 +1591,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
ret = down_read_killable(&mm->mmap_sem);
if (ret)
goto out_free;
- ret = walk_page_range(start_vaddr, end, &pagemap_walk);
+ ret = walk_page_range(mm, start_vaddr, end, &pagemap_ops, &pm);
up_read(&mm->mmap_sem);
start_vaddr = end;
@@ -1798,6 +1803,11 @@ static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
}
#endif
+static const struct mm_walk_ops show_numa_ops = {
+ .hugetlb_entry = gather_hugetlb_stats,
+ .pmd_entry = gather_pte_stats,
+};
+
/*
* Display pages allocated per node and memory policy via /proc.
*/
@@ -1809,12 +1819,6 @@ static int show_numa_map(struct seq_file *m, void *v)
struct numa_maps *md = &numa_priv->md;
struct file *file = vma->vm_file;
struct mm_struct *mm = vma->vm_mm;
- struct mm_walk walk = {
- .hugetlb_entry = gather_hugetlb_stats,
- .pmd_entry = gather_pte_stats,
- .private = md,
- .mm = mm,
- };
struct mempolicy *pol;
char buffer[64];
int nid;
@@ -1848,7 +1852,7 @@ static int show_numa_map(struct seq_file *m, void *v)
seq_puts(m, " huge");
/* mmap_sem is held by m_start */
- walk_page_vma(vma, &walk);
+ walk_page_vma(vma, &show_numa_ops, md);
if (!md->pages)
goto out;