From: Davidlohr Bueso <davidlohr@hp.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Michel Lespinasse <walken@google.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Rik van Riel <riel@redhat.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
aswin@hp.com, linux-mm <linux-mm@kvack.org>,
linux-kernel@vger.kernel.org, Davidlohr Bueso <davidlohr@hp.com>,
Vlastimil Babka <vbabka@suse.cz>
Subject: [PATCH 2/3] mm/mlock: prepare params outside critical region
Date: Thu, 17 Oct 2013 17:50:37 -0700 [thread overview]
Message-ID: <1382057438-3306-3-git-send-email-davidlohr@hp.com> (raw)
In-Reply-To: <1382057438-3306-1-git-send-email-davidlohr@hp.com>
All mlock related syscalls prepare lock limits, lengths and
start parameters with the mmap_sem held. Move this logic
outside of the critical region. For the case of mlock, continue
incrementing the amount already locked by mm->locked_vm with
the rwsem taken.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
---
mm/mlock.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/mm/mlock.c b/mm/mlock.c
index d480cd6..aa7de13 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -689,19 +689,21 @@ SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len)
lru_add_drain_all(); /* flush pagevec */
- down_write(¤t->mm->mmap_sem);
len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
start &= PAGE_MASK;
- locked = len >> PAGE_SHIFT;
- locked += current->mm->locked_vm;
-
lock_limit = rlimit(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
+ locked = len >> PAGE_SHIFT;
+
+ down_write(¤t->mm->mmap_sem);
+
+ locked += current->mm->locked_vm;
/* check against resource limits */
if ((locked <= lock_limit) || capable(CAP_IPC_LOCK))
error = do_mlock(start, len, 1);
+
up_write(¤t->mm->mmap_sem);
if (!error)
error = __mm_populate(start, len, 0);
@@ -712,11 +714,13 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len)
{
int ret;
- down_write(¤t->mm->mmap_sem);
len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
start &= PAGE_MASK;
+
+ down_write(¤t->mm->mmap_sem);
ret = do_mlock(start, len, 0);
up_write(¤t->mm->mmap_sem);
+
return ret;
}
@@ -761,12 +765,12 @@ SYSCALL_DEFINE1(mlockall, int, flags)
if (flags & MCL_CURRENT)
lru_add_drain_all(); /* flush pagevec */
- down_write(¤t->mm->mmap_sem);
-
lock_limit = rlimit(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
ret = -ENOMEM;
+ down_write(¤t->mm->mmap_sem);
+
if (!(flags & MCL_CURRENT) || (current->mm->total_vm <= lock_limit) ||
capable(CAP_IPC_LOCK))
ret = do_mlockall(flags);
--
1.8.1.4
--
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next prev parent reply other threads:[~2013-10-18 0:50 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-18 0:50 [PATCH 0/3] mm,vdso: preallocate new vmas Davidlohr Bueso
2013-10-18 0:50 ` [PATCH 1/3] mm: add mlock_future_check helper Davidlohr Bueso
2013-10-23 9:30 ` walken
2013-10-18 0:50 ` Davidlohr Bueso [this message]
2013-10-23 9:33 ` [PATCH 2/3] mm/mlock: prepare params outside critical region walken
2013-10-23 9:46 ` Vlastimil Babka
2013-10-18 0:50 ` [PATCH 3/3] vdso: preallocate new vmas Davidlohr Bueso
2013-10-18 1:17 ` Linus Torvalds
2013-10-18 5:59 ` Richard Weinberger
2013-10-18 6:05 ` [PATCH 4/3] x86/vdso: Optimize setup_additional_pages() Ingo Molnar
2013-10-21 3:52 ` Davidlohr Bueso
2013-10-21 5:27 ` Ingo Molnar
2013-10-21 3:26 ` [PATCH 3/3] vdso: preallocate new vmas Davidlohr Bueso
2013-10-23 9:53 ` walken
2013-10-25 0:55 ` Davidlohr Bueso
2013-10-22 15:48 ` [PATCH 0/3] mm,vdso: " walken
2013-10-22 16:20 ` Linus Torvalds
2013-10-22 17:04 ` Michel Lespinasse
2013-10-22 17:54 ` Andy Lutomirski
2013-10-23 10:13 ` Michel Lespinasse
2013-10-23 21:42 ` Andy Lutomirski
2013-10-23 2:46 ` Davidlohr Bueso
2013-11-05 0:39 ` Davidlohr Bueso
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