diff mbox series

[Cosmic,4/4] mm, hugetlbfs: pass fault address to cow handler

Message ID 7e939ec179d45ef8dd72d498270c10765c77c579.1536347216.git.joseph.salisbury@canonical.com
State New
Headers show
Series Fixes for LP:1730836 | expand

Commit Message

Joseph Salisbury Sept. 10, 2018, 5:19 p.m. UTC 
From: Huang Ying <ying.huang@intel.com>

BugLink: https://bugs.launchpad.net/bugs/1730836

This is to take better advantage of the general huge page copying
optimization.  Where, the target subpage will be copied last to avoid
the cache lines of target subpage to be evicted when copying other
subpages.  This works better if the address of the target subpage is
available when copying huge page.  So hugetlbfs page fault handlers are
changed to pass that information to hugetlb_cow().  This will benefit
workloads which don't access the begin of the hugetlbfs huge page after
the page fault under heavy cache contention.

Link: http://lkml.kernel.org/r/20180524005851.4079-5-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 974e6d66b6b5c6e2d6a3ccc18b2f9a0b472be5b4)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
---
 mm/hugetlb.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7affa9d..231f541 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3508,7 +3508,7 @@  static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
  * Keep the pte_same checks anyway to make transition from the mutex easier.
  */
 static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
-		       unsigned long haddr, pte_t *ptep,
+		       unsigned long address, pte_t *ptep,
 		       struct page *pagecache_page, spinlock_t *ptl)
 {
 	pte_t pte;
@@ -3517,6 +3517,7 @@  static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 	int ret = 0, outside_reserve = 0;
 	unsigned long mmun_start;	/* For mmu_notifiers */
 	unsigned long mmun_end;		/* For mmu_notifiers */
+	unsigned long haddr = address & huge_page_mask(h);
 
 	pte = huge_ptep_get(ptep);
 	old_page = pte_page(pte);
@@ -3591,7 +3592,7 @@  static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 		goto out_release_all;
 	}
 
-	copy_user_huge_page(new_page, old_page, haddr, vma,
+	copy_user_huge_page(new_page, old_page, address, vma,
 			    pages_per_huge_page(h));
 	__SetPageUptodate(new_page);
 	set_page_huge_active(new_page);