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authorMatthew Wilcox <willy@linux.intel.com>2017-02-24 14:57:02 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-24 17:46:54 -0800
commita00cc7d9dd93d66a3fb83fc52aa57a4bec51c517 (patch)
tree54d78e89c63e519cb9e00fdab9efbf3189ef2f5e /mm/pagewalk.c
parenta2d581675d485eb7188f521f36efc114639a3096 (diff)
mm, x86: add support for PUD-sized transparent hugepages
The current transparent hugepage code only supports PMDs. This patch adds support for transparent use of PUDs with DAX. It does not include support for anonymous pages. x86 support code also added. Most of this patch simply parallels the work that was done for huge PMDs. The only major difference is how the new ->pud_entry method in mm_walk works. The ->pmd_entry method replaces the ->pte_entry method, whereas the ->pud_entry method works along with either ->pmd_entry or ->pte_entry. The pagewalk code takes care of locking the PUD before calling ->pud_walk, so handlers do not need to worry whether the PUD is stable. [dave.jiang@intel.com: fix SMP x86 32bit build for native_pud_clear()] Link: http://lkml.kernel.org/r/148719066814.31111.3239231168815337012.stgit@djiang5-desk3.ch.intel.com [dave.jiang@intel.com: native_pud_clear missing on i386 build] Link: http://lkml.kernel.org/r/148640375195.69754.3315433724330910314.stgit@djiang5-desk3.ch.intel.com Link: http://lkml.kernel.org/r/148545059381.17912.8602162635537598445.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Alexander Kapshuk <alexander.kapshuk@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/pagewalk.c')
-rw-r--r--mm/pagewalk.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 207244489a68..03761577ae86 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -78,14 +78,32 @@ static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
pud = pud_offset(pgd, addr);
do {
+ again:
next = pud_addr_end(addr, end);
- if (pud_none_or_clear_bad(pud)) {
+ if (pud_none(*pud) || !walk->vma) {
if (walk->pte_hole)
err = walk->pte_hole(addr, next, walk);
if (err)
break;
continue;
}
+
+ if (walk->pud_entry) {
+ spinlock_t *ptl = pud_trans_huge_lock(pud, walk->vma);
+
+ if (ptl) {
+ err = walk->pud_entry(pud, addr, next, walk);
+ spin_unlock(ptl);
+ if (err)
+ break;
+ continue;
+ }
+ }
+
+ split_huge_pud(walk->vma, pud, addr);
+ if (pud_none(*pud))
+ goto again;
+
if (walk->pmd_entry || walk->pte_entry)
err = walk_pmd_range(pud, addr, next, walk);
if (err)