linux-kernel - [PATCH 5/9] mm: use mm_populate() when adjusting brk with MCL

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Date:	Thu, 20 Dec 2012 16:49:53 -0800
From:	Michel Lespinasse <walken@...gle.com>
To:	Andy Lutomirski <luto@...capital.net>,
	Ingo Molnar <mingo@...nel.org>,
	Al Viro <viro@...iv.linux.org.uk>,
	Hugh Dickins <hughd@...gle.com>, Jorn_Engel <joern@...fs.org>,
	Rik van Riel <riel@...hat.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 5/9] mm: use mm_populate() when adjusting brk with MCL_FUTURE in effect.

Signed-off-by: Michel Lespinasse <walken@...gle.com>

---
 mm/mmap.c |   18 ++++++++++++++----
 1 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index a16fc499dbd1..4c8d39e64e80 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -240,6 +240,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	unsigned long newbrk, oldbrk;
 	struct mm_struct *mm = current->mm;
 	unsigned long min_brk;
+	bool populate;
 
 	down_write(&mm->mmap_sem);
 
@@ -289,8 +290,15 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	/* Ok, looks good - let it rip. */
 	if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
 		goto out;
+
 set_brk:
 	mm->brk = brk;
+	populate = newbrk > oldbrk && (mm->def_flags & VM_LOCKED) != 0;
+	up_write(&mm->mmap_sem);
+	if (populate)
+		mm_populate(oldbrk, newbrk - oldbrk);
+	return brk;
+
 out:
 	retval = mm->brk;
 	up_write(&mm->mmap_sem);
@@ -2274,10 +2282,8 @@ static unsigned long do_brk(unsigned long addr, unsigned long len)
 out:
 	perf_event_mmap(vma);
 	mm->total_vm += len >> PAGE_SHIFT;
-	if (flags & VM_LOCKED) {
-		if (!mlock_vma_pages_range(vma, addr, addr + len))
-			mm->locked_vm += (len >> PAGE_SHIFT);
-	}
+	if (flags & VM_LOCKED)
+		mm->locked_vm += (len >> PAGE_SHIFT);
 	return addr;
 }
 
@@ -2285,10 +2291,14 @@ unsigned long vm_brk(unsigned long addr, unsigned long len)
 {
 	struct mm_struct *mm = current->mm;
 	unsigned long ret;
+	bool populate;
 
 	down_write(&mm->mmap_sem);
 	ret = do_brk(addr, len);
+	populate = ((mm->def_flags & VM_LOCKED) != 0);
 	up_write(&mm->mmap_sem);
+	if (populate)
+		mm_populate(addr, len);
 	return ret;
 }
 EXPORT_SYMBOL(vm_brk);
-- 
1.7.7.3
--
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