From: Mitchell Blank Jr <mitch@sfgoth.com>
This patch makes the following improvements to might_sleep():
o Add a "might_sleep_if()" macro for when we might sleep only if some
condition is met. It's a bit tidier, and has an unlikely() in it.
o Add might_sleep checks to skb_share_check() and skb_unshare() which
sometimes need to allocate memory.
o Make all architectures call might_sleep() in both down() and
down_interruptible(). Before only ppc, ppc64, and i386 did this check.
(sh did the check on down() but not down_interruptible())
25-akpm/arch/sparc64/kernel/semaphore.c | 2 ++
25-akpm/include/asm-alpha/semaphore.h | 8 ++++++--
25-akpm/include/asm-arm/semaphore.h | 4 ++--
25-akpm/include/asm-arm26/semaphore.h | 4 ++--
25-akpm/include/asm-cris/semaphore.h | 2 ++
25-akpm/include/asm-h8300/semaphore.h | 2 ++
25-akpm/include/asm-ia64/semaphore.h | 2 ++
25-akpm/include/asm-m68k/semaphore.h | 4 ++--
25-akpm/include/asm-m68knommu/semaphore.h | 4 ++--
25-akpm/include/asm-mips/semaphore.h | 2 ++
25-akpm/include/asm-parisc/semaphore.h | 4 ++--
25-akpm/include/asm-s390/semaphore.h | 2 ++
25-akpm/include/asm-sh/semaphore.h | 1 +
25-akpm/include/asm-sparc/semaphore.h | 2 ++
25-akpm/include/asm-v850/semaphore.h | 2 ++
25-akpm/include/asm-x86_64/semaphore.h | 2 ++
25-akpm/include/linux/kernel.h | 2 ++
25-akpm/include/linux/skbuff.h | 2 ++
25-akpm/mm/page_alloc.c | 3 +--
25-akpm/mm/rmap.c | 3 +--
25-akpm/mm/slab.c | 3 +--
21 files changed, 42 insertions(+), 18 deletions(-)
diff -puN arch/sparc64/kernel/semaphore.c~might_sleep-improvements arch/sparc64/kernel/semaphore.c
--- 25/arch/sparc64/kernel/semaphore.c~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/arch/sparc64/kernel/semaphore.c Tue Sep 2 08:19:47 2003
@@ -110,6 +110,7 @@ static void __down(struct semaphore * se
void down(struct semaphore *sem)
{
+ might_sleep();
/* This atomically does:
* old_val = sem->count;
* new_val = sem->count - 1;
@@ -219,6 +220,7 @@ int down_interruptible(struct semaphore
{
int ret = 0;
+ might_sleep();
/* This atomically does:
* old_val = sem->count;
* new_val = sem->count - 1;
diff -puN include/asm-alpha/semaphore.h~might_sleep-improvements include/asm-alpha/semaphore.h
--- 25/include/asm-alpha/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-alpha/semaphore.h Tue Sep 2 08:19:47 2003
@@ -88,14 +88,18 @@ extern void __up_wakeup(struct semaphore
static inline void __down(struct semaphore *sem)
{
- long count = atomic_dec_return(&sem->count);
+ long count;
+ might_sleep();
+ count = atomic_dec_return(&sem->count);
if (unlikely(count < 0))
__down_failed(sem);
}
static inline int __down_interruptible(struct semaphore *sem)
{
- long count = atomic_dec_return(&sem->count);
+ long count;
+ might_sleep();
+ count = atomic_dec_return(&sem->count);
if (unlikely(count < 0))
return __down_failed_interruptible(sem);
return 0;
diff -puN include/asm-arm26/semaphore.h~might_sleep-improvements include/asm-arm26/semaphore.h
--- 25/include/asm-arm26/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-arm26/semaphore.h Tue Sep 2 08:19:47 2003
@@ -84,7 +84,7 @@ static inline void down(struct semaphore
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
__down_op(sem, __down_failed);
}
@@ -97,7 +97,7 @@ static inline int down_interruptible (st
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
return __down_op_ret(sem, __down_interruptible_failed);
}
diff -puN include/asm-arm/semaphore.h~might_sleep-improvements include/asm-arm/semaphore.h
--- 25/include/asm-arm/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-arm/semaphore.h Tue Sep 2 08:19:47 2003
@@ -88,7 +88,7 @@ static inline void down(struct semaphore
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
__down_op(sem, __down_failed);
}
@@ -101,7 +101,7 @@ static inline int down_interruptible (st
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
return __down_op_ret(sem, __down_interruptible_failed);
}
diff -puN include/asm-cris/semaphore.h~might_sleep-improvements include/asm-cris/semaphore.h
--- 25/include/asm-cris/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-cris/semaphore.h Tue Sep 2 08:19:47 2003
@@ -79,6 +79,7 @@ extern inline void down(struct semaphore
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
/* atomically decrement the semaphores count, and if its negative, we wait */
local_save_flags(flags);
@@ -104,6 +105,7 @@ extern inline int down_interruptible(str
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
/* atomically decrement the semaphores count, and if its negative, we wait */
local_save_flags(flags);
diff -puN include/asm-h8300/semaphore.h~might_sleep-improvements include/asm-h8300/semaphore.h
--- 25/include/asm-h8300/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-h8300/semaphore.h Tue Sep 2 08:19:47 2003
@@ -90,6 +90,7 @@ static inline void down(struct semaphore
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
count = &(sem->count);
__asm__ __volatile__(
@@ -117,6 +118,7 @@ static inline int down_interruptible(str
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
count = &(sem->count);
__asm__ __volatile__(
diff -puN include/asm-ia64/semaphore.h~might_sleep-improvements include/asm-ia64/semaphore.h
--- 25/include/asm-ia64/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-ia64/semaphore.h Tue Sep 2 08:19:47 2003
@@ -73,6 +73,7 @@ down (struct semaphore *sem)
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
if (atomic_dec_return(&sem->count) < 0)
__down(sem);
}
@@ -89,6 +90,7 @@ down_interruptible (struct semaphore * s
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
if (atomic_dec_return(&sem->count) < 0)
ret = __down_interruptible(sem);
return ret;
diff -puN include/asm-m68knommu/semaphore.h~might_sleep-improvements include/asm-m68knommu/semaphore.h
--- 25/include/asm-m68knommu/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-m68knommu/semaphore.h Tue Sep 2 08:19:47 2003
@@ -88,7 +88,7 @@ extern inline void down(struct semaphore
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
__asm__ __volatile__(
"| atomic down operation\n\t"
"movel %0, %%a1\n\t"
@@ -108,7 +108,7 @@ extern inline int down_interruptible(str
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
__asm__ __volatile__(
"| atomic down operation\n\t"
"movel %1, %%a1\n\t"
diff -puN include/asm-m68k/semaphore.h~might_sleep-improvements include/asm-m68k/semaphore.h
--- 25/include/asm-m68k/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-m68k/semaphore.h Tue Sep 2 08:19:47 2003
@@ -89,7 +89,7 @@ extern inline void down(struct semaphore
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
__asm__ __volatile__(
"| atomic down operation\n\t"
"subql #1,%0@\n\t"
@@ -112,7 +112,7 @@ extern inline int down_interruptible(str
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
__asm__ __volatile__(
"| atomic interruptible down operation\n\t"
"subql #1,%1@\n\t"
diff -puN include/asm-mips/semaphore.h~might_sleep-improvements include/asm-mips/semaphore.h
--- 25/include/asm-mips/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-mips/semaphore.h Tue Sep 2 08:19:47 2003
@@ -88,6 +88,7 @@ static inline void down(struct semaphore
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
if (atomic_dec_return(&sem->count) < 0)
__down(sem);
}
@@ -103,6 +104,7 @@ static inline int down_interruptible(str
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
if (atomic_dec_return(&sem->count) < 0)
ret = __down_interruptible(sem);
return ret;
diff -puN include/asm-parisc/semaphore.h~might_sleep-improvements include/asm-parisc/semaphore.h
--- 25/include/asm-parisc/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-parisc/semaphore.h Tue Sep 2 08:19:47 2003
@@ -84,7 +84,7 @@ extern __inline__ void down(struct semap
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
spin_lock_irq(&sem->sentry);
if (sem->count > 0) {
sem->count--;
@@ -100,7 +100,7 @@ extern __inline__ int down_interruptible
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
-
+ might_sleep();
spin_lock_irq(&sem->sentry);
if (sem->count > 0) {
sem->count--;
diff -puN include/asm-s390/semaphore.h~might_sleep-improvements include/asm-s390/semaphore.h
--- 25/include/asm-s390/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-s390/semaphore.h Tue Sep 2 08:19:47 2003
@@ -60,6 +60,7 @@ asmlinkage void __up(struct semaphore *
static inline void down(struct semaphore * sem)
{
+ might_sleep();
if (atomic_dec_return(&sem->count) < 0)
__down(sem);
}
@@ -68,6 +69,7 @@ static inline int down_interruptible(str
{
int ret = 0;
+ might_sleep();
if (atomic_dec_return(&sem->count) < 0)
ret = __down_interruptible(sem);
return ret;
diff -puN include/asm-sh/semaphore.h~might_sleep-improvements include/asm-sh/semaphore.h
--- 25/include/asm-sh/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-sh/semaphore.h Tue Sep 2 08:19:47 2003
@@ -107,6 +107,7 @@ static inline int down_interruptible(str
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
if (atomic_dec_return(&sem->count) < 0)
ret = __down_interruptible(sem);
return ret;
diff -puN include/asm-sparc/semaphore.h~might_sleep-improvements include/asm-sparc/semaphore.h
--- 25/include/asm-sparc/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-sparc/semaphore.h Tue Sep 2 08:19:47 2003
@@ -71,6 +71,7 @@ static inline void down(struct semaphore
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
ptr = &(sem->count.counter);
increment = 1;
@@ -107,6 +108,7 @@ static inline int down_interruptible(str
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
ptr = &(sem->count.counter);
increment = 1;
diff -puN include/asm-v850/semaphore.h~might_sleep-improvements include/asm-v850/semaphore.h
--- 25/include/asm-v850/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-v850/semaphore.h Tue Sep 2 08:19:47 2003
@@ -57,6 +57,7 @@ extern void __up (struct semaphore * sem
extern inline void down (struct semaphore * sem)
{
+ might_sleep();
if (atomic_dec_return (&sem->count) < 0)
__down (sem);
}
@@ -64,6 +65,7 @@ extern inline void down (struct semaphor
extern inline int down_interruptible (struct semaphore * sem)
{
int ret = 0;
+ might_sleep();
if (atomic_dec_return (&sem->count) < 0)
ret = __down_interruptible (sem);
return ret;
diff -puN include/asm-x86_64/semaphore.h~might_sleep-improvements include/asm-x86_64/semaphore.h
--- 25/include/asm-x86_64/semaphore.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/asm-x86_64/semaphore.h Tue Sep 2 08:19:47 2003
@@ -118,6 +118,7 @@ static inline void down(struct semaphore
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
__asm__ __volatile__(
"# atomic down operation\n\t"
@@ -144,6 +145,7 @@ static inline int down_interruptible(str
#if WAITQUEUE_DEBUG
CHECK_MAGIC(sem->__magic);
#endif
+ might_sleep();
__asm__ __volatile__(
"# atomic interruptible down operation\n\t"
diff -puN include/linux/kernel.h~might_sleep-improvements include/linux/kernel.h
--- 25/include/linux/kernel.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/linux/kernel.h Tue Sep 2 08:19:47 2003
@@ -52,8 +52,10 @@ struct completion;
#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
void __might_sleep(char *file, int line);
#define might_sleep() __might_sleep(__FILE__, __LINE__)
+#define might_sleep_if(cond) do { if (unlikely(cond)) might_sleep(); } while (0)
#else
#define might_sleep() do {} while(0)
+#define might_sleep_if(cond) do {} while (0)
#endif
extern struct notifier_block *panic_notifier_list;
diff -puN include/linux/skbuff.h~might_sleep-improvements include/linux/skbuff.h
--- 25/include/linux/skbuff.h~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/include/linux/skbuff.h Tue Sep 2 08:19:47 2003
@@ -389,6 +389,7 @@ static inline int skb_shared(struct sk_b
*/
static inline struct sk_buff *skb_share_check(struct sk_buff *skb, int pri)
{
+ might_sleep_if(pri & __GFP_WAIT);
if (skb_shared(skb)) {
struct sk_buff *nskb = skb_clone(skb, pri);
kfree_skb(skb);
@@ -419,6 +420,7 @@ static inline struct sk_buff *skb_share_
*/
static inline struct sk_buff *skb_unshare(struct sk_buff *skb, int pri)
{
+ might_sleep_if(pri & __GFP_WAIT);
if (skb_cloned(skb)) {
struct sk_buff *nskb = skb_copy(skb, pri);
kfree_skb(skb); /* Free our shared copy */
diff -puN mm/page_alloc.c~might_sleep-improvements mm/page_alloc.c
--- 25/mm/page_alloc.c~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/mm/page_alloc.c Tue Sep 2 08:19:47 2003
@@ -545,8 +545,7 @@ __alloc_pages(unsigned int gfp_mask, uns
int cold;
int do_retry;
- if (wait)
- might_sleep();
+ might_sleep_if(wait);
cold = 0;
if (gfp_mask & __GFP_COLD)
diff -puN mm/rmap.c~might_sleep-improvements mm/rmap.c
--- 25/mm/rmap.c~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/mm/rmap.c Tue Sep 2 08:19:47 2003
@@ -503,8 +503,7 @@ struct pte_chain *pte_chain_alloc(int gf
struct pte_chain *ret;
struct pte_chain **pte_chainp;
- if (gfp_flags & __GFP_WAIT)
- might_sleep();
+ might_sleep_if(gfp_flags & __GFP_WAIT);
pte_chainp = &get_cpu_var(local_pte_chain);
if (*pte_chainp) {
diff -puN mm/slab.c~might_sleep-improvements mm/slab.c
--- 25/mm/slab.c~might_sleep-improvements Tue Sep 2 08:19:47 2003
+++ 25-akpm/mm/slab.c Tue Sep 2 08:19:47 2003
@@ -1818,8 +1818,7 @@ alloc_done:
static inline void
cache_alloc_debugcheck_before(kmem_cache_t *cachep, int flags)
{
- if (flags & __GFP_WAIT)
- might_sleep();
+ might_sleep_if(flags & __GFP_WAIT);
#if DEBUG
kmem_flagcheck(cachep, flags);
#endif
_