Subject: + mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock.patch added to -mm tree
To: kirill.shutemov@xxxxxxxxxxxxxxx,aarcange@xxxxxxxxxx,ak@xxxxxxxxxxxxxxx,athorlton@xxxxxxx,dave.hansen@xxxxxxxxx,davej@xxxxxxxxxx,dhowells@xxxxxxxxxx,ebiederm@xxxxxxxxxxxx,fweisbec@xxxxxxxxx,hannes@xxxxxxxxxxx,hughd@xxxxxxxxxx,keescook@xxxxxxxxxxxx,mgorman@xxxxxxx,mingo@xxxxxxxxxx,mtk.manpages@xxxxxxxxx,n-horiguchi@xxxxxxxxxxxxx,oleg@xxxxxxxxxx,paulmck@xxxxxxxxxxxxxxxxxx,peterz@xxxxxxxxxxxxx,riel@xxxxxxxxxx,robinmholt@xxxxxxxxx,sedat.dilek@xxxxxxxxx,srikar@xxxxxxxxxxxxxxxxxx,tglx@xxxxxxxxxxxxx,viro@xxxxxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 07 Oct 2013 16:10:10 -0700
The patch titled
Subject: mm, thp: change pmd_trans_huge_lock() to return taken lock
has been added to the -mm tree. Its filename is
mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: mm, thp: change pmd_trans_huge_lock() to return taken lock
With split ptlock it's important to know which lock pmd_trans_huge_lock()
took. This patch adds one more parameter to the function to return the
lock.
In most places migration to new api is trivial. Exception is
move_huge_pmd(): we need to take two locks if pmd tables are different.
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Tested-by: Alex Thorlton <athorlton@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "Eric W . Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: "Paul E . McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Robin Holt <robinmholt@xxxxxxxxx>
Cc: Sedat Dilek <sedat.dilek@xxxxxxxxx>
Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/task_mmu.c | 13 ++++++------
include/linux/huge_mm.h | 14 ++++++-------
mm/huge_memory.c | 40 +++++++++++++++++++++++++-------------
mm/memcontrol.c | 10 ++++-----
4 files changed, 46 insertions(+), 31 deletions(-)
diff -puN fs/proc/task_mmu.c~mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock fs/proc/task_mmu.c
--- a/fs/proc/task_mmu.c~mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock
+++ a/fs/proc/task_mmu.c
@@ -506,9 +506,9 @@ static int smaps_pte_range(pmd_t *pmd, u
pte_t *pte;
spinlock_t *ptl;
- if (pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
smaps_pte_entry(*(pte_t *)pmd, addr, HPAGE_PMD_SIZE, walk);
- spin_unlock(&walk->mm->page_table_lock);
+ spin_unlock(ptl);
mss->anonymous_thp += HPAGE_PMD_SIZE;
return 0;
}
@@ -994,13 +994,14 @@ static int pagemap_pte_range(pmd_t *pmd,
{
struct vm_area_struct *vma;
struct pagemapread *pm = walk->private;
+ spinlock_t *ptl;
pte_t *pte;
int err = 0;
pagemap_entry_t pme = make_pme(PM_NOT_PRESENT(pm->v2));
/* find the first VMA at or above 'addr' */
vma = find_vma(walk->mm, addr);
- if (vma && pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (vma && pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
int pmd_flags2;
if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(*pmd))
@@ -1018,7 +1019,7 @@ static int pagemap_pte_range(pmd_t *pmd,
if (err)
break;
}
- spin_unlock(&walk->mm->page_table_lock);
+ spin_unlock(ptl);
return err;
}
@@ -1320,7 +1321,7 @@ static int gather_pte_stats(pmd_t *pmd,
md = walk->private;
- if (pmd_trans_huge_lock(pmd, md->vma) == 1) {
+ if (pmd_trans_huge_lock(pmd, md->vma, &ptl) == 1) {
pte_t huge_pte = *(pte_t *)pmd;
struct page *page;
@@ -1328,7 +1329,7 @@ static int gather_pte_stats(pmd_t *pmd,
if (page)
gather_stats(page, md, pte_dirty(huge_pte),
HPAGE_PMD_SIZE/PAGE_SIZE);
- spin_unlock(&walk->mm->page_table_lock);
+ spin_unlock(ptl);
return 0;
}
diff -puN include/linux/huge_mm.h~mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock include/linux/huge_mm.h
--- a/include/linux/huge_mm.h~mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock
+++ a/include/linux/huge_mm.h
@@ -129,15 +129,15 @@ extern void __vma_adjust_trans_huge(stru
unsigned long start,
unsigned long end,
long adjust_next);
-extern int __pmd_trans_huge_lock(pmd_t *pmd,
- struct vm_area_struct *vma);
+extern int __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma,
+ spinlock_t **ptl);
/* mmap_sem must be held on entry */
-static inline int pmd_trans_huge_lock(pmd_t *pmd,
- struct vm_area_struct *vma)
+static inline int pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma,
+ spinlock_t **ptl)
{
VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
if (pmd_trans_huge(*pmd))
- return __pmd_trans_huge_lock(pmd, vma);
+ return __pmd_trans_huge_lock(pmd, vma, ptl);
else
return 0;
}
@@ -215,8 +215,8 @@ static inline void vma_adjust_trans_huge
long adjust_next)
{
}
-static inline int pmd_trans_huge_lock(pmd_t *pmd,
- struct vm_area_struct *vma)
+static inline int pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma,
+ spinlock_t **ptl)
{
return 0;
}
diff -puN mm/huge_memory.c~mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock mm/huge_memory.c
--- a/mm/huge_memory.c~mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock
+++ a/mm/huge_memory.c
@@ -1335,9 +1335,10 @@ out_unlock:
int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr)
{
+ spinlock_t *ptl;
int ret = 0;
- if (__pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
struct page *page;
pgtable_t pgtable;
pmd_t orig_pmd;
@@ -1352,7 +1353,7 @@ int zap_huge_pmd(struct mmu_gather *tlb,
pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
if (is_huge_zero_pmd(orig_pmd)) {
atomic_long_dec(&tlb->mm->nr_ptes);
- spin_unlock(&tlb->mm->page_table_lock);
+ spin_unlock(ptl);
put_huge_zero_page();
} else {
page = pmd_page(orig_pmd);
@@ -1361,7 +1362,7 @@ int zap_huge_pmd(struct mmu_gather *tlb,
add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
VM_BUG_ON(!PageHead(page));
atomic_long_dec(&tlb->mm->nr_ptes);
- spin_unlock(&tlb->mm->page_table_lock);
+ spin_unlock(ptl);
tlb_remove_page(tlb, page);
}
pte_free(tlb->mm, pgtable);
@@ -1374,14 +1375,15 @@ int mincore_huge_pmd(struct vm_area_stru
unsigned long addr, unsigned long end,
unsigned char *vec)
{
+ spinlock_t *ptl;
int ret = 0;
- if (__pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
/*
* All logical pages in the range are present
* if backed by a huge page.
*/
- spin_unlock(&vma->vm_mm->page_table_lock);
+ spin_unlock(ptl);
memset(vec, 1, (end - addr) >> PAGE_SHIFT);
ret = 1;
}
@@ -1394,6 +1396,7 @@ int move_huge_pmd(struct vm_area_struct
unsigned long new_addr, unsigned long old_end,
pmd_t *old_pmd, pmd_t *new_pmd)
{
+ spinlock_t *old_ptl, *new_ptl;
int ret = 0;
pmd_t pmd;
@@ -1414,12 +1417,21 @@ int move_huge_pmd(struct vm_area_struct
goto out;
}
- ret = __pmd_trans_huge_lock(old_pmd, vma);
+ /*
+ * We don't have to worry about the ordering of src and dst
+ * ptlocks because exclusive mmap_sem prevents deadlock.
+ */
+ ret = __pmd_trans_huge_lock(old_pmd, vma, &old_ptl);
if (ret == 1) {
+ new_ptl = pmd_lockptr(mm, new_pmd);
+ if (new_ptl != old_ptl)
+ spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
VM_BUG_ON(!pmd_none(*new_pmd));
set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
- spin_unlock(&mm->page_table_lock);
+ if (new_ptl != old_ptl)
+ spin_unlock(new_ptl);
+ spin_unlock(old_ptl);
}
out:
return ret;
@@ -1429,9 +1441,10 @@ int change_huge_pmd(struct vm_area_struc
unsigned long addr, pgprot_t newprot, int prot_numa)
{
struct mm_struct *mm = vma->vm_mm;
+ spinlock_t *ptl;
int ret = 0;
- if (__pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
pmd_t entry;
entry = pmdp_get_and_clear(mm, addr, pmd);
if (!prot_numa) {
@@ -1447,7 +1460,7 @@ int change_huge_pmd(struct vm_area_struc
}
}
set_pmd_at(mm, addr, pmd, entry);
- spin_unlock(&vma->vm_mm->page_table_lock);
+ spin_unlock(ptl);
ret = 1;
}
@@ -1461,12 +1474,13 @@ int change_huge_pmd(struct vm_area_struc
* Note that if it returns 1, this routine returns without unlocking page
* table locks. So callers must unlock them.
*/
-int __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma)
+int __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma,
+ spinlock_t **ptl)
{
- spin_lock(&vma->vm_mm->page_table_lock);
+ *ptl = pmd_lock(vma->vm_mm, pmd);
if (likely(pmd_trans_huge(*pmd))) {
if (unlikely(pmd_trans_splitting(*pmd))) {
- spin_unlock(&vma->vm_mm->page_table_lock);
+ spin_unlock(*ptl);
wait_split_huge_page(vma->anon_vma, pmd);
return -1;
} else {
@@ -1475,7 +1489,7 @@ int __pmd_trans_huge_lock(pmd_t *pmd, st
return 1;
}
}
- spin_unlock(&vma->vm_mm->page_table_lock);
+ spin_unlock(*ptl);
return 0;
}
diff -puN mm/memcontrol.c~mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock mm/memcontrol.c
--- a/mm/memcontrol.c~mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock
+++ a/mm/memcontrol.c
@@ -6629,10 +6629,10 @@ static int mem_cgroup_count_precharge_pt
pte_t *pte;
spinlock_t *ptl;
- if (pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
mc.precharge += HPAGE_PMD_NR;
- spin_unlock(&vma->vm_mm->page_table_lock);
+ spin_unlock(ptl);
return 0;
}
@@ -6821,9 +6821,9 @@ static int mem_cgroup_move_charge_pte_ra
* to be unlocked in __split_huge_page_splitting(), where the main
* part of thp split is not executed yet.
*/
- if (pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
if (mc.precharge < HPAGE_PMD_NR) {
- spin_unlock(&vma->vm_mm->page_table_lock);
+ spin_unlock(ptl);
return 0;
}
target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
@@ -6840,7 +6840,7 @@ static int mem_cgroup_move_charge_pte_ra
}
put_page(page);
}
- spin_unlock(&vma->vm_mm->page_table_lock);
+ spin_unlock(ptl);
return 0;
}
_
Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are
mm-huge_memoryc-fix-stale-comments-of-transparent_hugepage_flags.patch
mm-thp-cleanup-mv-alloc_hugepage-to-better-place.patch
mm-thp-khugepaged-add-policy-for-finding-target-node.patch
mm-thp-khugepaged-add-policy-for-finding-target-node-fix.patch
mm-avoid-increase-sizeofstruct-page-due-to-split-page-table-lock.patch
mm-rename-use_split_ptlocks-to-use_split_pte_ptlocks.patch
mm-convert-mm-nr_ptes-to-atomic_long_t.patch
mm-introduce-api-for-split-page-table-lock-for-pmd-level.patch
mm-thp-change-pmd_trans_huge_lock-to-return-taken-lock.patch
mm-thp-move-ptl-taking-inside-page_check_address_pmd.patch
mm-thp-do-not-access-mm-pmd_huge_pte-directly.patch
mm-hugetlb-convert-hugetlbfs-to-use-split-pmd-lock.patch
mm-convert-the-rest-to-new-page-table-lock-api.patch
mm-implement-split-page-table-lock-for-pmd-level.patch
x86-mm-enable-split-page-table-lock-for-pmd-level.patch
thp-mm-locking-tail-page-is-a-bug.patch
mm-drop-actor-argument-of-do_generic_file_read.patch
mm-drop-actor-argument-of-do_generic_file_read-fix.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
