The patch titled
memcgroup: temporarily revert swapoff mod
has been removed from the -mm tree. Its filename was
memcgroup-temporarily-revert-swapoff-mod.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: memcgroup: temporarily revert swapoff mod
From: Hugh Dickins <hugh@xxxxxxxxxxx>
This patch precisely reverts the "swapoff: scan ptes preemptibly" patch
just presented. It's a temporary measure to allow existing memory
controller patches to apply without rejects: in due course they should be
rendered down into one sensible patch, and this reversion disappear.
Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 38 +++++++-------------------------------
1 file changed, 7 insertions(+), 31 deletions(-)
diff -puN mm/swapfile.c~memcgroup-temporarily-revert-swapoff-mod mm/swapfile.c
--- a/mm/swapfile.c~memcgroup-temporarily-revert-swapoff-mod
+++ a/mm/swapfile.c
@@ -506,19 +506,9 @@ unsigned int count_swap_pages(int type,
* just let do_wp_page work it out if a write is requested later - to
* force COW, vm_page_prot omits write permission from any private vma.
*/
-static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
+static void unuse_pte(struct vm_area_struct *vma, pte_t *pte,
unsigned long addr, swp_entry_t entry, struct page *page)
{
- spinlock_t *ptl;
- pte_t *pte;
- int found = 1;
-
- pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
- if (unlikely(!pte_same(*pte, swp_entry_to_pte(entry)))) {
- found = 0;
- goto out;
- }
-
inc_mm_counter(vma->vm_mm, anon_rss);
get_page(page);
set_pte_at(vma->vm_mm, addr, pte,
@@ -530,9 +520,6 @@ static int unuse_pte(struct vm_area_stru
* immediately swapped out again after swapon.
*/
activate_page(page);
-out:
- pte_unmap_unlock(pte, ptl);
- return found;
}
static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
@@ -541,33 +528,22 @@ static int unuse_pte_range(struct vm_are
{
pte_t swp_pte = swp_entry_to_pte(entry);
pte_t *pte;
+ spinlock_t *ptl;
int found = 0;
- /*
- * We don't actually need pte lock while scanning for swp_pte: since
- * we hold page lock and mmap_sem, swp_pte cannot be inserted into the
- * page table while we're scanning; though it could get zapped, and on
- * some architectures (e.g. x86_32 with PAE) we might catch a glimpse
- * of unmatched parts which look like swp_pte, so unuse_pte must
- * recheck under pte lock. Scanning without pte lock lets it be
- * preemptible whenever CONFIG_PREEMPT but not CONFIG_HIGHPTE.
- */
- pte = pte_offset_map(pmd, addr);
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
/*
* swapoff spends a _lot_ of time in this loop!
* Test inline before going to call unuse_pte.
*/
if (unlikely(pte_same(*pte, swp_pte))) {
- pte_unmap(pte);
- found = unuse_pte(vma, pmd, addr, entry, page);
- if (found)
- goto out;
- pte = pte_offset_map(pmd, addr);
+ unuse_pte(vma, pte++, addr, entry, page);
+ found = 1;
+ break;
}
} while (pte++, addr += PAGE_SIZE, addr != end);
- pte_unmap(pte - 1);
-out:
+ pte_unmap_unlock(pte - 1, ptl);
return found;
}
_
Patches currently in -mm which might be from hugh@xxxxxxxxxxx are
origin.patch
git-unionfs.patch
git-x86.patch
r-o-bind-mounts-track-number-of-mount-writers.patch
mount-options-fix-tmpfs.patch
mount-options-fix-tmpfs-fix.patch
add-new-string-functions-strict_strto-and-convert-kernel-params-to-use-them-fix-2.patch
procfs-task-exe-symlink.patch
procfs-task-exe-symlink-fix.patch
prio_tree-debugging-patch.patch
-
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