diff mbox series

[v2] locking/local_lock, mm: Replace localtry_ helpers with local_trylock_t type

Message ID 20250401205245.70838-1-alexei.starovoitov@gmail.com (mailing list archive)
State New
Headers show
Series [v2] locking/local_lock, mm: Replace localtry_ helpers with local_trylock_t type | expand

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Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Alexei Starovoitov April 1, 2025, 8:52 p.m. UTC 
From: Alexei Starovoitov <ast@kernel.org>

Partially revert commit 0aaddfb06882 ("locking/local_lock: Introduce localtry_lock_t").
Remove localtry_*() helpers, since localtry_lock() name might
be misinterpreted as "try lock".

Introduce local_trylock[_irqsave]() helpers that only work
with newly introduced local_trylock_t type.
Note that attempt to use local_trylock[_irqsave]() with local_lock_t
will cause compilation failure.

Usage and behavior in !PREEMPT_RT:

local_lock_t lock;                     // sizeof(lock) == 0
local_lock(&lock);                     // preempt disable
local_lock_irqsave(&lock, ...);        // irq save
if (local_trylock_irqsave(&lock, ...)) // compilation error

local_trylock_t lock;                  // sizeof(lock) == 4
local_lock(&lock);                     // preempt disable, acquired = 1
local_lock_irqsave(&lock, ...);        // irq save, acquired = 1
if (local_trylock(&lock))              // if (!acquired) preempt disable
if (local_trylock_irqsave(&lock, ...)) // if (!acquired) irq save

The existing local_lock_*() macros can be used either with
local_lock_t or local_trylock_t.
With local_trylock_t they set acquired = 1 while local_unlock_*() clears it.

In !PREEMPT_RT local_lock_irqsave(local_lock_t *) disables interrupts
to protect critical section, but it doesn't prevent NMI, so the fully
reentrant code cannot use local_lock_irqsave(local_lock_t *) for
exclusive access.

The local_lock_irqsave(local_trylock_t *) helper disables interrupts
and sets acquired=1, so local_trylock_irqsave(local_trylock_t *) from
NMI attempting to acquire the same lock will return false.

In PREEMPT_RT local_lock_irqsave() maps to preemptible spin_lock().
Map local_trylock_irqsave() to preemptible spin_trylock().
When in hard IRQ or NMI return false right away, since
spin_trylock() is not safe due to explicit locking in the underneath
rt_spin_trylock() implementation. Removing this explicit locking and
attempting only "trylock" is undesired due to PI implications.

The local_trylock() without _irqsave can be used to avoid the cost of
disabling/enabling interrupts by only disabling preemption, so
local_trylock() in an interrupt attempting to acquire the same
lock will return false.

Note there is no need to use local_inc for acquired variable,
since it's a percpu variable with strict nesting scopes.

Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 include/linux/local_lock.h          |  59 +-------
 include/linux/local_lock_internal.h | 208 ++++++++++++----------------
 mm/memcontrol.c                     |  39 +++---
 3 files changed, 111 insertions(+), 195 deletions(-)

Comments

Shakeel Butt April 2, 2025, 8:56 p.m. UTC | #1 
On Tue, Apr 01, 2025 at 01:52:45PM -0700, Alexei Starovoitov wrote:
> From: Alexei Starovoitov <ast@kernel.org>
> 
> Partially revert commit 0aaddfb06882 ("locking/local_lock: Introduce localtry_lock_t").
> Remove localtry_*() helpers, since localtry_lock() name might
> be misinterpreted as "try lock".
> 
> Introduce local_trylock[_irqsave]() helpers that only work
> with newly introduced local_trylock_t type.
> Note that attempt to use local_trylock[_irqsave]() with local_lock_t
> will cause compilation failure.
> 
> Usage and behavior in !PREEMPT_RT:
> 
> local_lock_t lock;                     // sizeof(lock) == 0
> local_lock(&lock);                     // preempt disable
> local_lock_irqsave(&lock, ...);        // irq save
> if (local_trylock_irqsave(&lock, ...)) // compilation error
> 
> local_trylock_t lock;                  // sizeof(lock) == 4

Is there a reason for this 'acquired' to be int? Can it be uint8_t? No
need to change anything here but I plan to change it later to compact as
much as possible within one (or two) cachline for memcg stocks.

> local_lock(&lock);                     // preempt disable, acquired = 1
> local_lock_irqsave(&lock, ...);        // irq save, acquired = 1
> if (local_trylock(&lock))              // if (!acquired) preempt disable
> if (local_trylock_irqsave(&lock, ...)) // if (!acquired) irq save

For above two ", acquired = 1" as well.

> 
> The existing local_lock_*() macros can be used either with
> local_lock_t or local_trylock_t.
> With local_trylock_t they set acquired = 1 while local_unlock_*() clears it.
> 
> In !PREEMPT_RT local_lock_irqsave(local_lock_t *) disables interrupts
> to protect critical section, but it doesn't prevent NMI, so the fully
> reentrant code cannot use local_lock_irqsave(local_lock_t *) for
> exclusive access.
> 
> The local_lock_irqsave(local_trylock_t *) helper disables interrupts
> and sets acquired=1, so local_trylock_irqsave(local_trylock_t *) from
> NMI attempting to acquire the same lock will return false.
> 
> In PREEMPT_RT local_lock_irqsave() maps to preemptible spin_lock().
> Map local_trylock_irqsave() to preemptible spin_trylock().
> When in hard IRQ or NMI return false right away, since
> spin_trylock() is not safe due to explicit locking in the underneath
> rt_spin_trylock() implementation. Removing this explicit locking and
> attempting only "trylock" is undesired due to PI implications.
> 
> The local_trylock() without _irqsave can be used to avoid the cost of
> disabling/enabling interrupts by only disabling preemption, so
> local_trylock() in an interrupt attempting to acquire the same
> lock will return false.
> 
> Note there is no need to use local_inc for acquired variable,
> since it's a percpu variable with strict nesting scopes.
> 
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Alexei Starovoitov April 2, 2025, 9:40 p.m. UTC | #2 
On Wed, Apr 2, 2025 at 1:56 PM Shakeel Butt <shakeel.butt@linux.dev> wrote:
>
> On Tue, Apr 01, 2025 at 01:52:45PM -0700, Alexei Starovoitov wrote:
> > From: Alexei Starovoitov <ast@kernel.org>
> >
> > Partially revert commit 0aaddfb06882 ("locking/local_lock: Introduce localtry_lock_t").
> > Remove localtry_*() helpers, since localtry_lock() name might
> > be misinterpreted as "try lock".
> >
> > Introduce local_trylock[_irqsave]() helpers that only work
> > with newly introduced local_trylock_t type.
> > Note that attempt to use local_trylock[_irqsave]() with local_lock_t
> > will cause compilation failure.
> >
> > Usage and behavior in !PREEMPT_RT:
> >
> > local_lock_t lock;                     // sizeof(lock) == 0
> > local_lock(&lock);                     // preempt disable
> > local_lock_irqsave(&lock, ...);        // irq save
> > if (local_trylock_irqsave(&lock, ...)) // compilation error
> >
> > local_trylock_t lock;                  // sizeof(lock) == 4
>
> Is there a reason for this 'acquired' to be int? Can it be uint8_t? No
> need to change anything here but I plan to change it later to compact as
> much as possible within one (or two) cachline for memcg stocks.

I don't see any issue. I can make it u8 right away.

> > local_lock(&lock);                     // preempt disable, acquired = 1
> > local_lock_irqsave(&lock, ...);        // irq save, acquired = 1
> > if (local_trylock(&lock))              // if (!acquired) preempt disable
> > if (local_trylock_irqsave(&lock, ...)) // if (!acquired) irq save
>
> For above two ", acquired = 1" as well.

I felt it would be too verbose and not accurate anyway,
since irq save will be done before the check.
It's a pseudo code.
But sure, I can add.

>
> >
> > The existing local_lock_*() macros can be used either with
> > local_lock_t or local_trylock_t.
> > With local_trylock_t they set acquired = 1 while local_unlock_*() clears it.
> >
> > In !PREEMPT_RT local_lock_irqsave(local_lock_t *) disables interrupts
> > to protect critical section, but it doesn't prevent NMI, so the fully
> > reentrant code cannot use local_lock_irqsave(local_lock_t *) for
> > exclusive access.
> >
> > The local_lock_irqsave(local_trylock_t *) helper disables interrupts
> > and sets acquired=1, so local_trylock_irqsave(local_trylock_t *) from
> > NMI attempting to acquire the same lock will return false.
> >
> > In PREEMPT_RT local_lock_irqsave() maps to preemptible spin_lock().
> > Map local_trylock_irqsave() to preemptible spin_trylock().
> > When in hard IRQ or NMI return false right away, since
> > spin_trylock() is not safe due to explicit locking in the underneath
> > rt_spin_trylock() implementation. Removing this explicit locking and
> > attempting only "trylock" is undesired due to PI implications.
> >
> > The local_trylock() without _irqsave can be used to avoid the cost of
> > disabling/enabling interrupts by only disabling preemption, so
> > local_trylock() in an interrupt attempting to acquire the same
> > lock will return false.
> >
> > Note there is no need to use local_inc for acquired variable,
> > since it's a percpu variable with strict nesting scopes.
> >
> > Acked-by: Vlastimil Babka <vbabka@suse.cz>
> > Signed-off-by: Alexei Starovoitov <ast@kernel.org>
>
> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>

Thanks!
diff mbox series

Patch

diff --git a/include/linux/local_lock.h b/include/linux/local_lock.h
index 1a0bc35839e3..7ac9385cd475 100644
--- a/include/linux/local_lock.h
+++ b/include/linux/local_lock.h
@@ -52,44 +52,18 @@ 
 	__local_unlock_irqrestore(lock, flags)
 
 /**
- * localtry_lock_init - Runtime initialize a lock instance
- */
-#define localtry_lock_init(lock)		__localtry_lock_init(lock)
-
-/**
- * localtry_lock - Acquire a per CPU local lock
- * @lock:	The lock variable
- */
-#define localtry_lock(lock)		__localtry_lock(lock)
-
-/**
- * localtry_lock_irq - Acquire a per CPU local lock and disable interrupts
- * @lock:	The lock variable
- */
-#define localtry_lock_irq(lock)		__localtry_lock_irq(lock)
-
-/**
- * localtry_lock_irqsave - Acquire a per CPU local lock, save and disable
- *			 interrupts
- * @lock:	The lock variable
- * @flags:	Storage for interrupt flags
- */
-#define localtry_lock_irqsave(lock, flags)				\
-	__localtry_lock_irqsave(lock, flags)
-
-/**
- * localtry_trylock - Try to acquire a per CPU local lock.
+ * local_trylock - Try to acquire a per CPU local lock
  * @lock:	The lock variable
  *
  * The function can be used in any context such as NMI or HARDIRQ. Due to
  * locking constrains it will _always_ fail to acquire the lock in NMI or
  * HARDIRQ context on PREEMPT_RT.
  */
-#define localtry_trylock(lock)		__localtry_trylock(lock)
+#define local_trylock(lock)		__local_trylock(lock)
 
 /**
- * localtry_trylock_irqsave - Try to acquire a per CPU local lock, save and disable
- *			      interrupts if acquired
+ * local_trylock_irqsave - Try to acquire a per CPU local lock, save and disable
+ *			   interrupts if acquired
  * @lock:	The lock variable
  * @flags:	Storage for interrupt flags
  *
@@ -97,29 +71,8 @@ 
  * locking constrains it will _always_ fail to acquire the lock in NMI or
  * HARDIRQ context on PREEMPT_RT.
  */
-#define localtry_trylock_irqsave(lock, flags)				\
-	__localtry_trylock_irqsave(lock, flags)
-
-/**
- * local_unlock - Release a per CPU local lock
- * @lock:	The lock variable
- */
-#define localtry_unlock(lock)		__localtry_unlock(lock)
-
-/**
- * local_unlock_irq - Release a per CPU local lock and enable interrupts
- * @lock:	The lock variable
- */
-#define localtry_unlock_irq(lock)		__localtry_unlock_irq(lock)
-
-/**
- * localtry_unlock_irqrestore - Release a per CPU local lock and restore
- *			      interrupt flags
- * @lock:	The lock variable
- * @flags:      Interrupt flags to restore
- */
-#define localtry_unlock_irqrestore(lock, flags)			\
-	__localtry_unlock_irqrestore(lock, flags)
+#define local_trylock_irqsave(lock, flags)			\
+	__local_trylock_irqsave(lock, flags)
 
 DEFINE_GUARD(local_lock, local_lock_t __percpu*,
 	     local_lock(_T),
diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h
index 67bd13d142fa..2389ae4f69a6 100644
--- a/include/linux/local_lock_internal.h
+++ b/include/linux/local_lock_internal.h
@@ -15,10 +15,18 @@  typedef struct {
 #endif
 } local_lock_t;
 
+/* local_trylock() and local_trylock_irqsave() only work with local_trylock_t */
 typedef struct {
-	local_lock_t	llock;
-	unsigned int	acquired;
-} localtry_lock_t;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+	struct task_struct	*owner;
+#endif
+	/*
+	 * Same layout as local_lock_t with 'acquired' field at the end.
+	 * (local_trylock_t *) will be cast to (local_lock_t *).
+	 */
+	int acquired;
+} local_trylock_t;
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 # define LOCAL_LOCK_DEBUG_INIT(lockname)		\
@@ -63,7 +71,6 @@  static inline void local_lock_debug_init(local_lock_t *l) { }
 #endif /* !CONFIG_DEBUG_LOCK_ALLOC */
 
 #define INIT_LOCAL_LOCK(lockname)	{ LOCAL_LOCK_DEBUG_INIT(lockname) }
-#define INIT_LOCALTRY_LOCK(lockname)	{ .llock = { LOCAL_LOCK_DEBUG_INIT(lockname.llock) }}
 
 #define __local_lock_init(lock)					\
 do {								\
@@ -73,7 +80,7 @@  do {								\
 	lockdep_init_map_type(&(lock)->dep_map, #lock, &__key,  \
 			      0, LD_WAIT_CONFIG, LD_WAIT_INV,	\
 			      LD_LOCK_PERCPU);			\
-	local_lock_debug_init(lock);				\
+	local_lock_debug_init((local_lock_t *)lock);		\
 } while (0)
 
 #define __spinlock_nested_bh_init(lock)				\
@@ -87,149 +94,117 @@  do {								\
 	local_lock_debug_init(lock);				\
 } while (0)
 
+#define __local_lock_acquire(lock)					\
+	do {								\
+		local_trylock_t *tl;					\
+		local_lock_t *l;					\
+									\
+		l = (local_lock_t *)this_cpu_ptr(lock);			\
+		tl = (local_trylock_t *)l;				\
+		_Generic((lock),					\
+			local_trylock_t *: ({				\
+				lockdep_assert(tl->acquired == 0);	\
+				WRITE_ONCE(tl->acquired, 1);		\
+			}),						\
+			default:(void)0);				\
+		local_lock_acquire(l);					\
+	} while (0)
+
 #define __local_lock(lock)					\
 	do {							\
 		preempt_disable();				\
-		local_lock_acquire(this_cpu_ptr(lock));		\
+		__local_lock_acquire(lock);			\
 	} while (0)
 
 #define __local_lock_irq(lock)					\
 	do {							\
 		local_irq_disable();				\
-		local_lock_acquire(this_cpu_ptr(lock));		\
+		__local_lock_acquire(lock);			\
 	} while (0)
 
 #define __local_lock_irqsave(lock, flags)			\
 	do {							\
 		local_irq_save(flags);				\
-		local_lock_acquire(this_cpu_ptr(lock));		\
-	} while (0)
-
-#define __local_unlock(lock)					\
-	do {							\
-		local_lock_release(this_cpu_ptr(lock));		\
-		preempt_enable();				\
-	} while (0)
-
-#define __local_unlock_irq(lock)				\
-	do {							\
-		local_lock_release(this_cpu_ptr(lock));		\
-		local_irq_enable();				\
+		__local_lock_acquire(lock);			\
 	} while (0)
 
-#define __local_unlock_irqrestore(lock, flags)			\
-	do {							\
-		local_lock_release(this_cpu_ptr(lock));		\
-		local_irq_restore(flags);			\
-	} while (0)
-
-#define __local_lock_nested_bh(lock)				\
-	do {							\
-		lockdep_assert_in_softirq();			\
-		local_lock_acquire(this_cpu_ptr(lock));	\
-	} while (0)
-
-#define __local_unlock_nested_bh(lock)				\
-	local_lock_release(this_cpu_ptr(lock))
-
-/* localtry_lock_t variants */
-
-#define __localtry_lock_init(lock)				\
-do {								\
-	__local_lock_init(&(lock)->llock);			\
-	WRITE_ONCE((lock)->acquired, 0);			\
-} while (0)
-
-#define __localtry_lock(lock)					\
-	do {							\
-		localtry_lock_t *lt;				\
-		preempt_disable();				\
-		lt = this_cpu_ptr(lock);			\
-		local_lock_acquire(&lt->llock);			\
-		WRITE_ONCE(lt->acquired, 1);			\
-	} while (0)
-
-#define __localtry_lock_irq(lock)				\
-	do {							\
-		localtry_lock_t *lt;				\
-		local_irq_disable();				\
-		lt = this_cpu_ptr(lock);			\
-		local_lock_acquire(&lt->llock);			\
-		WRITE_ONCE(lt->acquired, 1);			\
-	} while (0)
-
-#define __localtry_lock_irqsave(lock, flags)			\
-	do {							\
-		localtry_lock_t *lt;				\
-		local_irq_save(flags);				\
-		lt = this_cpu_ptr(lock);			\
-		local_lock_acquire(&lt->llock);			\
-		WRITE_ONCE(lt->acquired, 1);			\
-	} while (0)
-
-#define __localtry_trylock(lock)				\
+#define __local_trylock(lock)					\
 	({							\
-		localtry_lock_t *lt;				\
-		bool _ret;					\
+		local_trylock_t *tl;				\
 								\
 		preempt_disable();				\
-		lt = this_cpu_ptr(lock);			\
-		if (!READ_ONCE(lt->acquired)) {			\
-			WRITE_ONCE(lt->acquired, 1);		\
-			local_trylock_acquire(&lt->llock);	\
-			_ret = true;				\
-		} else {					\
-			_ret = false;				\
+		tl = this_cpu_ptr(lock);			\
+		if (READ_ONCE(tl->acquired)) {			\
 			preempt_enable();			\
+			tl = NULL;				\
+		} else {					\
+			WRITE_ONCE(tl->acquired, 1);		\
+			local_trylock_acquire(			\
+				(local_lock_t *)tl);		\
 		}						\
-		_ret;						\
+		!!tl;						\
 	})
 
-#define __localtry_trylock_irqsave(lock, flags)			\
+#define __local_trylock_irqsave(lock, flags)			\
 	({							\
-		localtry_lock_t *lt;				\
-		bool _ret;					\
+		local_trylock_t *tl;				\
 								\
 		local_irq_save(flags);				\
-		lt = this_cpu_ptr(lock);			\
-		if (!READ_ONCE(lt->acquired)) {			\
-			WRITE_ONCE(lt->acquired, 1);		\
-			local_trylock_acquire(&lt->llock);	\
-			_ret = true;				\
-		} else {					\
-			_ret = false;				\
+		tl = this_cpu_ptr(lock);			\
+		if (READ_ONCE(tl->acquired)) {			\
 			local_irq_restore(flags);		\
+			tl = NULL;				\
+		} else {					\
+			WRITE_ONCE(tl->acquired, 1);		\
+			local_trylock_acquire(			\
+				(local_lock_t *)tl);		\
 		}						\
-		_ret;						\
+		!!tl;						\
 	})
 
-#define __localtry_unlock(lock)					\
+#define __local_lock_release(lock)					\
+	do {								\
+		local_trylock_t *tl;					\
+		local_lock_t *l;					\
+									\
+		l = (local_lock_t *)this_cpu_ptr(lock);			\
+		tl = (local_trylock_t *)l;				\
+		_Generic((lock),					\
+			local_trylock_t *: ({				\
+				lockdep_assert(tl->acquired == 1);	\
+				WRITE_ONCE(tl->acquired, 0);		\
+			}),						\
+			default:(void)0);				\
+		local_lock_release(l);					\
+	} while (0)
+
+#define __local_unlock(lock)					\
 	do {							\
-		localtry_lock_t *lt;				\
-		lt = this_cpu_ptr(lock);			\
-		WRITE_ONCE(lt->acquired, 0);			\
-		local_lock_release(&lt->llock);			\
+		__local_lock_release(lock);			\
 		preempt_enable();				\
 	} while (0)
 
-#define __localtry_unlock_irq(lock)				\
+#define __local_unlock_irq(lock)				\
 	do {							\
-		localtry_lock_t *lt;				\
-		lt = this_cpu_ptr(lock);			\
-		WRITE_ONCE(lt->acquired, 0);			\
-		local_lock_release(&lt->llock);			\
+		__local_lock_release(lock);			\
 		local_irq_enable();				\
 	} while (0)
 
-#define __localtry_unlock_irqrestore(lock, flags)		\
+#define __local_unlock_irqrestore(lock, flags)			\
 	do {							\
-		localtry_lock_t *lt;				\
-		lt = this_cpu_ptr(lock);			\
-		WRITE_ONCE(lt->acquired, 0);			\
-		local_lock_release(&lt->llock);			\
+		__local_lock_release(lock);			\
 		local_irq_restore(flags);			\
 	} while (0)
 
+#define __local_lock_nested_bh(lock)				\
+	do {							\
+		lockdep_assert_in_softirq();			\
+		local_lock_acquire(this_cpu_ptr(lock));	\
+	} while (0)
+
+#define __local_unlock_nested_bh(lock)				\
+	local_lock_release(this_cpu_ptr(lock))
+
 #else /* !CONFIG_PREEMPT_RT */
 
 /*
@@ -237,10 +212,9 @@  do {								\
  * critical section while staying preemptible.
  */
 typedef spinlock_t local_lock_t;
-typedef spinlock_t localtry_lock_t;
+typedef spinlock_t local_trylock_t;
 
 #define INIT_LOCAL_LOCK(lockname) __LOCAL_SPIN_LOCK_UNLOCKED((lockname))
-#define INIT_LOCALTRY_LOCK(lockname) INIT_LOCAL_LOCK(lockname)
 
 #define __local_lock_init(l)					\
 	do {							\
@@ -283,17 +257,7 @@  do {								\
 	spin_unlock(this_cpu_ptr((lock)));			\
 } while (0)
 
-/* localtry_lock_t variants */
-
-#define __localtry_lock_init(lock)			__local_lock_init(lock)
-#define __localtry_lock(lock)				__local_lock(lock)
-#define __localtry_lock_irq(lock)			__local_lock(lock)
-#define __localtry_lock_irqsave(lock, flags)		__local_lock_irqsave(lock, flags)
-#define __localtry_unlock(lock)				__local_unlock(lock)
-#define __localtry_unlock_irq(lock)			__local_unlock(lock)
-#define __localtry_unlock_irqrestore(lock, flags)	__local_unlock_irqrestore(lock, flags)
-
-#define __localtry_trylock(lock)				\
+#define __local_trylock(lock)					\
 	({							\
 		int __locked;					\
 								\
@@ -308,11 +272,11 @@  do {								\
 		__locked;					\
 	})
 
-#define __localtry_trylock_irqsave(lock, flags)			\
+#define __local_trylock_irqsave(lock, flags)			\
 	({							\
 		typecheck(unsigned long, flags);		\
 		flags = 0;					\
-		__localtry_trylock(lock);			\
+		__local_trylock(lock);				\
 	})
 
 #endif /* CONFIG_PREEMPT_RT */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 421740f1bcdc..813f5b73e7c8 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1759,7 +1759,7 @@  void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
 }
 
 struct memcg_stock_pcp {
-	localtry_lock_t stock_lock;
+	local_trylock_t stock_lock;
 	struct mem_cgroup *cached; /* this never be root cgroup */
 	unsigned int nr_pages;
 
@@ -1774,7 +1774,7 @@  struct memcg_stock_pcp {
 #define FLUSHING_CACHED_CHARGE	0
 };
 static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock) = {
-	.stock_lock = INIT_LOCALTRY_LOCK(stock_lock),
+	.stock_lock = INIT_LOCAL_LOCK(stock_lock),
 };
 static DEFINE_MUTEX(percpu_charge_mutex);
 
@@ -1805,11 +1805,10 @@  static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages,
 	if (nr_pages > MEMCG_CHARGE_BATCH)
 		return ret;
 
-	if (!localtry_trylock_irqsave(&memcg_stock.stock_lock, flags)) {
-		if (!gfpflags_allow_spinning(gfp_mask))
-			return ret;
-		localtry_lock_irqsave(&memcg_stock.stock_lock, flags);
-	}
+	if (gfpflags_allow_spinning(gfp_mask))
+		local_lock_irqsave(&memcg_stock.stock_lock, flags);
+	else if (!local_trylock_irqsave(&memcg_stock.stock_lock, flags))
+		return ret;
 
 	stock = this_cpu_ptr(&memcg_stock);
 	stock_pages = READ_ONCE(stock->nr_pages);
@@ -1818,7 +1817,7 @@  static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages,
 		ret = true;
 	}
 
-	localtry_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 
 	return ret;
 }
@@ -1857,14 +1856,14 @@  static void drain_local_stock(struct work_struct *dummy)
 	 * drain_stock races is that we always operate on local CPU stock
 	 * here with IRQ disabled
 	 */
-	localtry_lock_irqsave(&memcg_stock.stock_lock, flags);
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
 
 	stock = this_cpu_ptr(&memcg_stock);
 	old = drain_obj_stock(stock);
 	drain_stock(stock);
 	clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
 
-	localtry_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 	obj_cgroup_put(old);
 }
 
@@ -1894,7 +1893,7 @@  static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
 {
 	unsigned long flags;
 
-	if (!localtry_trylock_irqsave(&memcg_stock.stock_lock, flags)) {
+	if (!local_trylock_irqsave(&memcg_stock.stock_lock, flags)) {
 		/*
 		 * In case of unlikely failure to lock percpu stock_lock
 		 * uncharge memcg directly.
@@ -1907,7 +1906,7 @@  static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
 		return;
 	}
 	__refill_stock(memcg, nr_pages);
-	localtry_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 }
 
 /*
@@ -1964,9 +1963,9 @@  static int memcg_hotplug_cpu_dead(unsigned int cpu)
 	stock = &per_cpu(memcg_stock, cpu);
 
 	/* drain_obj_stock requires stock_lock */
-	localtry_lock_irqsave(&memcg_stock.stock_lock, flags);
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
 	old = drain_obj_stock(stock);
-	localtry_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 
 	drain_stock(stock);
 	obj_cgroup_put(old);
@@ -2787,7 +2786,7 @@  static void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
 	unsigned long flags;
 	int *bytes;
 
-	localtry_lock_irqsave(&memcg_stock.stock_lock, flags);
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
 	stock = this_cpu_ptr(&memcg_stock);
 
 	/*
@@ -2836,7 +2835,7 @@  static void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
 	if (nr)
 		__mod_objcg_mlstate(objcg, pgdat, idx, nr);
 
-	localtry_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 	obj_cgroup_put(old);
 }
 
@@ -2846,7 +2845,7 @@  static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes)
 	unsigned long flags;
 	bool ret = false;
 
-	localtry_lock_irqsave(&memcg_stock.stock_lock, flags);
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
 
 	stock = this_cpu_ptr(&memcg_stock);
 	if (objcg == READ_ONCE(stock->cached_objcg) && stock->nr_bytes >= nr_bytes) {
@@ -2854,7 +2853,7 @@  static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes)
 		ret = true;
 	}
 
-	localtry_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 
 	return ret;
 }
@@ -2946,7 +2945,7 @@  static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes,
 	unsigned long flags;
 	unsigned int nr_pages = 0;
 
-	localtry_lock_irqsave(&memcg_stock.stock_lock, flags);
+	local_lock_irqsave(&memcg_stock.stock_lock, flags);
 
 	stock = this_cpu_ptr(&memcg_stock);
 	if (READ_ONCE(stock->cached_objcg) != objcg) { /* reset if necessary */
@@ -2960,7 +2959,7 @@  static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes,
 		stock->nr_bytes &= (PAGE_SIZE - 1);
 	}
 
-	localtry_unlock_irqrestore(&memcg_stock.stock_lock, flags);
+	local_unlock_irqrestore(&memcg_stock.stock_lock, flags);
 	obj_cgroup_put(old);
 
 	if (nr_pages)