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authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2012-07-31 16:42:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-31 18:42:40 -0700
commit24669e58477e2752c1fbca9c1c988e9dd0d79d15 (patch)
treea4fe04fc1cc2b5a2d89b67f745185b9e9640426f /mm
parent972dc4de13f667a7df27ee32573b2e6fc6cc8434 (diff)
hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages
Use a mmu_gather instead of a temporary linked list for accumulating pages when we unmap a hugepage range Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/hugetlb.c59
-rw-r--r--mm/memory.c7
2 files changed, 40 insertions, 26 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b1e0ed1ea912..e54b695336f9 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -24,8 +24,9 @@
#include <asm/page.h>
#include <asm/pgtable.h>
-#include <linux/io.h>
+#include <asm/tlb.h>
+#include <linux/io.h>
#include <linux/hugetlb.h>
#include <linux/node.h>
#include "internal.h"
@@ -2310,30 +2311,26 @@ static int is_hugetlb_entry_hwpoisoned(pte_t pte)
return 0;
}
-void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
- unsigned long end, struct page *ref_page)
+void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
+ unsigned long start, unsigned long end,
+ struct page *ref_page)
{
+ int force_flush = 0;
struct mm_struct *mm = vma->vm_mm;
unsigned long address;
pte_t *ptep;
pte_t pte;
struct page *page;
- struct page *tmp;
struct hstate *h = hstate_vma(vma);
unsigned long sz = huge_page_size(h);
- /*
- * A page gathering list, protected by per file i_mmap_mutex. The
- * lock is used to avoid list corruption from multiple unmapping
- * of the same page since we are using page->lru.
- */
- LIST_HEAD(page_list);
-
WARN_ON(!is_vm_hugetlb_page(vma));
BUG_ON(start & ~huge_page_mask(h));
BUG_ON(end & ~huge_page_mask(h));
+ tlb_start_vma(tlb, vma);
mmu_notifier_invalidate_range_start(mm, start, end);
+again:
spin_lock(&mm->page_table_lock);
for (address = start; address < end; address += sz) {
ptep = huge_pte_offset(mm, address);
@@ -2372,30 +2369,45 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
}
pte = huge_ptep_get_and_clear(mm, address, ptep);
+ tlb_remove_tlb_entry(tlb, ptep, address);
if (pte_dirty(pte))
set_page_dirty(page);
- list_add(&page->lru, &page_list);
+ page_remove_rmap(page);
+ force_flush = !__tlb_remove_page(tlb, page);
+ if (force_flush)
+ break;
/* Bail out after unmapping reference page if supplied */
if (ref_page)
break;
}
- flush_tlb_range(vma, start, end);
spin_unlock(&mm->page_table_lock);
- mmu_notifier_invalidate_range_end(mm, start, end);
- list_for_each_entry_safe(page, tmp, &page_list, lru) {
- page_remove_rmap(page);
- list_del(&page->lru);
- put_page(page);
+ /*
+ * mmu_gather ran out of room to batch pages, we break out of
+ * the PTE lock to avoid doing the potential expensive TLB invalidate
+ * and page-free while holding it.
+ */
+ if (force_flush) {
+ force_flush = 0;
+ tlb_flush_mmu(tlb);
+ if (address < end && !ref_page)
+ goto again;
}
+ mmu_notifier_invalidate_range_end(mm, start, end);
+ tlb_end_vma(tlb, vma);
}
void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end, struct page *ref_page)
{
- mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
- __unmap_hugepage_range(vma, start, end, ref_page);
- mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
+ struct mm_struct *mm;
+ struct mmu_gather tlb;
+
+ mm = vma->vm_mm;
+
+ tlb_gather_mmu(&tlb, mm, 0);
+ __unmap_hugepage_range(&tlb, vma, start, end, ref_page);
+ tlb_finish_mmu(&tlb, start, end);
}
/*
@@ -2440,9 +2452,8 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
* from the time of fork. This would look like data corruption
*/
if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
- __unmap_hugepage_range(iter_vma,
- address, address + huge_page_size(h),
- page);
+ unmap_hugepage_range(iter_vma, address,
+ address + huge_page_size(h), page);
}
mutex_unlock(&mapping->i_mmap_mutex);
diff --git a/mm/memory.c b/mm/memory.c
index 91f69459d3e8..59e5bebc2e35 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1343,8 +1343,11 @@ static void unmap_single_vma(struct mmu_gather *tlb,
* Since no pte has actually been setup, it is
* safe to do nothing in this case.
*/
- if (vma->vm_file)
- unmap_hugepage_range(vma, start, end, NULL);
+ if (vma->vm_file) {
+ mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
+ __unmap_hugepage_range(tlb, vma, start, end, NULL);
+ mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
+ }
} else
unmap_page_range(tlb, vma, start, end, details);
}