From 5cd3f5affad2109fd1458aab3f6216f2181e26ea Mon Sep 17 00:00:00 2001 From: Paul Bolle Date: Thu, 24 Jan 2013 21:53:17 +0100 Subject: lockdep: Silence warning if CONFIG_LOCKDEP isn't set MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since commit c9a4962881929df7f1ef6e63e1b9da304faca4dd ("nfsd: make client_lock per net") compiling nfs4state.o without CONFIG_LOCKDEP set, triggers this GCC warning: fs/nfsd/nfs4state.c: In function ‘free_client’: fs/nfsd/nfs4state.c:1051:19: warning: unused variable ‘nn’ [-Wunused-variable] The cause of that warning is that lockdep_assert_held() compiles away if CONFIG_LOCKDEP is not set. Silence this warning by using the argument to lockdep_assert_held() as a nop if CONFIG_LOCKDEP is not set. Signed-off-by: Paul Bolle Cc: Peter Zijlstra Cc: Stanislav Kinsbursky Cc: J. Bruce Fields Link: http://lkml.kernel.org/r/1359060797.1325.33.camel@x61.thuisdomein Signed-off-by: Ingo Molnar -- include/linux/lockdep.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- include/linux/lockdep.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 2bca44b0893c..f05631effc73 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -410,7 +410,7 @@ struct lock_class_key { }; #define lockdep_depth(tsk) (0) -#define lockdep_assert_held(l) do { } while (0) +#define lockdep_assert_held(l) do { (void)(l); } while (0) #define lockdep_recursing(tsk) (0) -- cgit v1.2.3 From eece09ec213e93333010bf4c6bb9175b32229c54 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 17 Jul 2011 21:25:03 +0200 Subject: locking: Various static lock initializer fixes The static lock initializers want to be fed the proper name of the lock and not some random string. In mainline random strings are obfuscating the readability of debug output, but for RT they prevent the spinlock substitution. Fix it up. Signed-off-by: Thomas Gleixner --- drivers/char/random.c | 6 +++--- drivers/usb/chipidea/debug.c | 2 +- fs/file.c | 2 +- include/linux/idr.h | 2 +- 4 files changed, 6 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/drivers/char/random.c b/drivers/char/random.c index 85e81ec1451e..594bda9dcfc8 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -445,7 +445,7 @@ static struct entropy_store input_pool = { .poolinfo = &poolinfo_table[0], .name = "input", .limit = 1, - .lock = __SPIN_LOCK_UNLOCKED(&input_pool.lock), + .lock = __SPIN_LOCK_UNLOCKED(input_pool.lock), .pool = input_pool_data }; @@ -454,7 +454,7 @@ static struct entropy_store blocking_pool = { .name = "blocking", .limit = 1, .pull = &input_pool, - .lock = __SPIN_LOCK_UNLOCKED(&blocking_pool.lock), + .lock = __SPIN_LOCK_UNLOCKED(blocking_pool.lock), .pool = blocking_pool_data }; @@ -462,7 +462,7 @@ static struct entropy_store nonblocking_pool = { .poolinfo = &poolinfo_table[1], .name = "nonblocking", .pull = &input_pool, - .lock = __SPIN_LOCK_UNLOCKED(&nonblocking_pool.lock), + .lock = __SPIN_LOCK_UNLOCKED(nonblocking_pool.lock), .pool = nonblocking_pool_data }; diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c index 3bc244d2636a..a62c4a47d52c 100644 --- a/drivers/usb/chipidea/debug.c +++ b/drivers/usb/chipidea/debug.c @@ -222,7 +222,7 @@ static struct { } dbg_data = { .idx = 0, .tty = 0, - .lck = __RW_LOCK_UNLOCKED(lck) + .lck = __RW_LOCK_UNLOCKED(dbg_data.lck) }; /** diff --git a/fs/file.c b/fs/file.c index 2b3570b7caeb..3906d9577a18 100644 --- a/fs/file.c +++ b/fs/file.c @@ -516,7 +516,7 @@ struct files_struct init_files = { .close_on_exec = init_files.close_on_exec_init, .open_fds = init_files.open_fds_init, }, - .file_lock = __SPIN_LOCK_UNLOCKED(init_task.file_lock), + .file_lock = __SPIN_LOCK_UNLOCKED(init_files.file_lock), }; /* diff --git a/include/linux/idr.h b/include/linux/idr.h index de7e190f1af4..e5eb125effe6 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -136,7 +136,7 @@ struct ida { struct ida_bitmap *free_bitmap; }; -#define IDA_INIT(name) { .idr = IDR_INIT(name), .free_bitmap = NULL, } +#define IDA_INIT(name) { .idr = IDR_INIT((name).idr), .free_bitmap = NULL, } #define DEFINE_IDA(name) struct ida name = IDA_INIT(name) int ida_pre_get(struct ida *ida, gfp_t gfp_mask); -- cgit v1.2.3 From 65c9d1bbc9f32c568a4f7ad154c9a10b0028df52 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 16 Jul 2011 18:38:22 +0200 Subject: seqlock: Remove unused functions Signed-off-by: Thomas Gleixner --- include/linux/seqlock.h | 21 --------------------- 1 file changed, 21 deletions(-) (limited to 'include') diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index 600060e25ec6..cb0599ca049c 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -69,17 +69,6 @@ static inline void write_sequnlock(seqlock_t *sl) spin_unlock(&sl->lock); } -static inline int write_tryseqlock(seqlock_t *sl) -{ - int ret = spin_trylock(&sl->lock); - - if (ret) { - ++sl->sequence; - smp_wmb(); - } - return ret; -} - /* Start of read calculation -- fetch last complete writer token */ static __always_inline unsigned read_seqbegin(const seqlock_t *sl) { @@ -269,14 +258,4 @@ static inline void write_seqcount_barrier(seqcount_t *s) #define write_sequnlock_bh(lock) \ do { write_sequnlock(lock); local_bh_enable(); } while(0) -#define read_seqbegin_irqsave(lock, flags) \ - ({ local_irq_save(flags); read_seqbegin(lock); }) - -#define read_seqretry_irqrestore(lock, iv, flags) \ - ({ \ - int ret = read_seqretry(lock, iv); \ - local_irq_restore(flags); \ - ret; \ - }) - #endif /* __LINUX_SEQLOCK_H */ -- cgit v1.2.3 From 6617feca15c68aad12f4a1edd8d8e2ef8d5b4ae5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 16 Jul 2011 18:40:26 +0200 Subject: seqlock: Use seqcount infrastructure No point in having different implementations for the same thing. Change the macro mess to inline functions where possible. Signed-off-by: Thomas Gleixner --- include/linux/seqlock.h | 174 +++++++++++++++++++++++++----------------------- 1 file changed, 92 insertions(+), 82 deletions(-) (limited to 'include') diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index cb0599ca049c..18299057402f 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -30,81 +30,12 @@ #include #include -typedef struct { - unsigned sequence; - spinlock_t lock; -} seqlock_t; - -/* - * These macros triggered gcc-3.x compile-time problems. We think these are - * OK now. Be cautious. - */ -#define __SEQLOCK_UNLOCKED(lockname) \ - { 0, __SPIN_LOCK_UNLOCKED(lockname) } - -#define seqlock_init(x) \ - do { \ - (x)->sequence = 0; \ - spin_lock_init(&(x)->lock); \ - } while (0) - -#define DEFINE_SEQLOCK(x) \ - seqlock_t x = __SEQLOCK_UNLOCKED(x) - -/* Lock out other writers and update the count. - * Acts like a normal spin_lock/unlock. - * Don't need preempt_disable() because that is in the spin_lock already. - */ -static inline void write_seqlock(seqlock_t *sl) -{ - spin_lock(&sl->lock); - ++sl->sequence; - smp_wmb(); -} - -static inline void write_sequnlock(seqlock_t *sl) -{ - smp_wmb(); - sl->sequence++; - spin_unlock(&sl->lock); -} - -/* Start of read calculation -- fetch last complete writer token */ -static __always_inline unsigned read_seqbegin(const seqlock_t *sl) -{ - unsigned ret; - -repeat: - ret = ACCESS_ONCE(sl->sequence); - if (unlikely(ret & 1)) { - cpu_relax(); - goto repeat; - } - smp_rmb(); - - return ret; -} - -/* - * Test if reader processed invalid data. - * - * If sequence value changed then writer changed data while in section. - */ -static __always_inline int read_seqretry(const seqlock_t *sl, unsigned start) -{ - smp_rmb(); - - return unlikely(sl->sequence != start); -} - - /* * Version using sequence counter only. * This can be used when code has its own mutex protecting the * updating starting before the write_seqcountbeqin() and ending * after the write_seqcount_end(). */ - typedef struct seqcount { unsigned sequence; } seqcount_t; @@ -207,7 +138,6 @@ static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start) static inline int read_seqcount_retry(const seqcount_t *s, unsigned start) { smp_rmb(); - return __read_seqcount_retry(s, start); } @@ -241,21 +171,101 @@ static inline void write_seqcount_barrier(seqcount_t *s) s->sequence+=2; } +typedef struct { + struct seqcount seqcount; + spinlock_t lock; +} seqlock_t; + +/* + * These macros triggered gcc-3.x compile-time problems. We think these are + * OK now. Be cautious. + */ +#define __SEQLOCK_UNLOCKED(lockname) \ + { \ + .seqcount = SEQCNT_ZERO, \ + .lock = __SPIN_LOCK_UNLOCKED(lockname) \ + } + +#define seqlock_init(x) \ + do { \ + seqcount_init(&(x)->seqcount); \ + spin_lock_init(&(x)->lock); \ + } while (0) + +#define DEFINE_SEQLOCK(x) \ + seqlock_t x = __SEQLOCK_UNLOCKED(x) + +/* + * Read side functions for starting and finalizing a read side section. + */ +static inline unsigned read_seqbegin(const seqlock_t *sl) +{ + return read_seqcount_begin(&sl->seqcount); +} + +static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start) +{ + return read_seqcount_retry(&sl->seqcount, start); +} + /* - * Possible sw/hw IRQ protected versions of the interfaces. + * Lock out other writers and update the count. + * Acts like a normal spin_lock/unlock. + * Don't need preempt_disable() because that is in the spin_lock already. */ +static inline void write_seqlock(seqlock_t *sl) +{ + spin_lock(&sl->lock); + write_seqcount_begin(&sl->seqcount); +} + +static inline void write_sequnlock(seqlock_t *sl) +{ + write_seqcount_end(&sl->seqcount); + spin_unlock(&sl->lock); +} + +static inline void write_seqlock_bh(seqlock_t *sl) +{ + spin_lock_bh(&sl->lock); + write_seqcount_begin(&sl->seqcount); +} + +static inline void write_sequnlock_bh(seqlock_t *sl) +{ + write_seqcount_end(&sl->seqcount); + spin_unlock_bh(&sl->lock); +} + +static inline void write_seqlock_irq(seqlock_t *sl) +{ + spin_lock_irq(&sl->lock); + write_seqcount_begin(&sl->seqcount); +} + +static inline void write_sequnlock_irq(seqlock_t *sl) +{ + write_seqcount_end(&sl->seqcount); + spin_unlock_irq(&sl->lock); +} + +static inline unsigned long __write_seqlock_irqsave(seqlock_t *sl) +{ + unsigned long flags; + + spin_lock_irqsave(&sl->lock, flags); + write_seqcount_begin(&sl->seqcount); + return flags; +} + #define write_seqlock_irqsave(lock, flags) \ - do { local_irq_save(flags); write_seqlock(lock); } while (0) -#define write_seqlock_irq(lock) \ - do { local_irq_disable(); write_seqlock(lock); } while (0) -#define write_seqlock_bh(lock) \ - do { local_bh_disable(); write_seqlock(lock); } while (0) + do { flags = __write_seqlock_irqsave(lock); } while (0) -#define write_sequnlock_irqrestore(lock, flags) \ - do { write_sequnlock(lock); local_irq_restore(flags); } while(0) -#define write_sequnlock_irq(lock) \ - do { write_sequnlock(lock); local_irq_enable(); } while(0) -#define write_sequnlock_bh(lock) \ - do { write_sequnlock(lock); local_bh_enable(); } while(0) +static inline void +write_sequnlock_irqrestore(seqlock_t *sl, unsigned long flags) +{ + write_seqcount_end(&sl->seqcount); + spin_unlock_irqrestore(&sl->lock, flags); +} #endif /* __LINUX_SEQLOCK_H */ -- cgit v1.2.3 From 5042afe7fe32390e79910ecd0a1f0563d4bca38c Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 3 Jul 2009 08:29:30 -0500 Subject: generic: Use raw local irq variant for generic cmpxchg The interrupt disabled region is extremly tiny and therefor not latency relevant. Avoid cluttering the traces with those pointless entries. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/asm-generic/cmpxchg-local.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/asm-generic/cmpxchg-local.h b/include/asm-generic/cmpxchg-local.h index 2533fddd34a6..d8d4c898c1bb 100644 --- a/include/asm-generic/cmpxchg-local.h +++ b/include/asm-generic/cmpxchg-local.h @@ -21,7 +21,7 @@ static inline unsigned long __cmpxchg_local_generic(volatile void *ptr, if (size == 8 && sizeof(unsigned long) != 8) wrong_size_cmpxchg(ptr); - local_irq_save(flags); + raw_local_irq_save(flags); switch (size) { case 1: prev = *(u8 *)ptr; if (prev == old) @@ -42,7 +42,7 @@ static inline unsigned long __cmpxchg_local_generic(volatile void *ptr, default: wrong_size_cmpxchg(ptr); } - local_irq_restore(flags); + raw_local_irq_restore(flags); return prev; } @@ -55,11 +55,11 @@ static inline u64 __cmpxchg64_local_generic(volatile void *ptr, u64 prev; unsigned long flags; - local_irq_save(flags); + raw_local_irq_save(flags); prev = *(u64 *)ptr; if (prev == old) *(u64 *)ptr = new; - local_irq_restore(flags); + raw_local_irq_restore(flags); return prev; } -- cgit v1.2.3