Re: [PATCH 2/3] mm/mlock: prepare params outside critical region

2013-10-23 Thread Vlastimil Babka 
On 10/18/2013 02:50 AM, Davidlohr Bueso wrote:
> 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 
> Cc: Michel Lespinasse 
> Cc: Vlastimil Babka 

Acked-by: Vlastimil Babka 

> ---
>  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(>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(>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(>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(>mm->mmap_sem);
>   len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
>   start &= PAGE_MASK;
> +
> + down_write(>mm->mmap_sem);
>   ret = do_mlock(start, len, 0);
>   up_write(>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(>mm->mmap_sem);
> -
>   lock_limit = rlimit(RLIMIT_MEMLOCK);
>   lock_limit >>= PAGE_SHIFT;
>  
>   ret = -ENOMEM;
> + down_write(>mm->mmap_sem);
> +
>   if (!(flags & MCL_CURRENT) || (current->mm->total_vm <= lock_limit) ||
>   capable(CAP_IPC_LOCK))
>   ret = do_mlockall(flags);
> 

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Re: [PATCH 2/3] mm/mlock: prepare params outside critical region

2013-10-23 Thread walken 
On Thu, Oct 17, 2013 at 05:50:37PM -0700, Davidlohr Bueso wrote:
> 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 
> Cc: Michel Lespinasse 
> Cc: Vlastimil Babka 

Reviewed-by: Michel Lespinasse 

-- 
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
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Re: [PATCH 2/3] mm/mlock: prepare params outside critical region

2013-10-23 Thread walken 
On Thu, Oct 17, 2013 at 05:50:37PM -0700, Davidlohr Bueso wrote:
 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 davidl...@hp.com
 Cc: Michel Lespinasse wal...@google.com
 Cc: Vlastimil Babka vba...@suse.cz

Reviewed-by: Michel Lespinasse wal...@google.com

-- 
Michel Walken Lespinasse
A program is never fully debugged until the last user dies.
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Re: [PATCH 2/3] mm/mlock: prepare params outside critical region

2013-10-23 Thread Vlastimil Babka 
On 10/18/2013 02:50 AM, Davidlohr Bueso wrote:
 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 davidl...@hp.com
 Cc: Michel Lespinasse wal...@google.com
 Cc: Vlastimil Babka vba...@suse.cz

Acked-by: Vlastimil Babka vba...@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(current-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(current-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(current-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(current-mm-mmap_sem);
   len = PAGE_ALIGN(len + (start  ~PAGE_MASK));
   start = PAGE_MASK;
 +
 + down_write(current-mm-mmap_sem);
   ret = do_mlock(start, len, 0);
   up_write(current-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(current-mm-mmap_sem);
 -
   lock_limit = rlimit(RLIMIT_MEMLOCK);
   lock_limit = PAGE_SHIFT;
  
   ret = -ENOMEM;
 + down_write(current-mm-mmap_sem);
 +
   if (!(flags  MCL_CURRENT) || (current-mm-total_vm = lock_limit) ||
   capable(CAP_IPC_LOCK))
   ret = do_mlockall(flags);
 

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[PATCH 2/3] mm/mlock: prepare params outside critical region

2013-10-17 Thread Davidlohr Bueso 
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 
Cc: Michel Lespinasse 
Cc: Vlastimil Babka 
---
 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(>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(>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(>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(>mm->mmap_sem);
len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
start &= PAGE_MASK;
+
+   down_write(>mm->mmap_sem);
ret = do_mlock(start, len, 0);
up_write(>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(>mm->mmap_sem);
-
lock_limit = rlimit(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
 
ret = -ENOMEM;
+   down_write(>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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[PATCH 2/3] mm/mlock: prepare params outside critical region

2013-10-17 Thread Davidlohr Bueso 
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 davidl...@hp.com
Cc: Michel Lespinasse wal...@google.com
Cc: Vlastimil Babka vba...@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(current-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(current-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(current-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(current-mm-mmap_sem);
len = PAGE_ALIGN(len + (start  ~PAGE_MASK));
start = PAGE_MASK;
+
+   down_write(current-mm-mmap_sem);
ret = do_mlock(start, len, 0);
up_write(current-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(current-mm-mmap_sem);
-
lock_limit = rlimit(RLIMIT_MEMLOCK);
lock_limit = PAGE_SHIFT;
 
ret = -ENOMEM;
+   down_write(current-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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