From: Peter Zijlstra Date: Thu, 22 Jan 2009 17:10:42 +0000 (+0100) Subject: lockdep: simplify check_prev_add_irq() X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=4f367d8adca947bed4385740a13d1efb1a06fba1;p=linux-2.6-omap-h63xx.git lockdep: simplify check_prev_add_irq() Remove the manual state iteration thingy. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 22ced8d4912..42dfc28d12c 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -1268,68 +1268,84 @@ check_usage(struct task_struct *curr, struct held_lock *prev, bit_backwards, bit_forwards, irqclass); } -static int -check_prev_add_irq(struct task_struct *curr, struct held_lock *prev, - struct held_lock *next) +static const char *state_names[] = { +#define LOCKDEP_STATE(__STATE) \ + STR(__STATE), +#include "lockdep_states.h" +#undef LOCKDEP_STATE +}; + +static const char *state_rnames[] = { +#define LOCKDEP_STATE(__STATE) \ + STR(__STATE)"-READ", +#include "lockdep_states.h" +#undef LOCKDEP_STATE +}; + +static inline const char *state_name(enum lock_usage_bit bit) { - /* - * Prove that the new dependency does not connect a hardirq-safe - * lock with a hardirq-unsafe lock - to achieve this we search - * the backwards-subgraph starting at , and the - * forwards-subgraph starting at : - */ - if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ, - LOCK_ENABLED_HARDIRQ, "hard")) - return 0; + return (bit & 1) ? state_rnames[bit >> 2] : state_names[bit >> 2]; +} +static int exclusive_bit(int new_bit) +{ /* - * Prove that the new dependency does not connect a hardirq-safe-read - * lock with a hardirq-unsafe lock - to achieve this we search - * the backwards-subgraph starting at , and the - * forwards-subgraph starting at : + * USED_IN + * USED_IN_READ + * ENABLED + * ENABLED_READ + * + * bit 0 - write/read + * bit 1 - used_in/enabled + * bit 2+ state */ - if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ_READ, - LOCK_ENABLED_HARDIRQ, "hard-read")) - return 0; + + int state = new_bit & ~3; + int dir = new_bit & 2; /* - * Prove that the new dependency does not connect a softirq-safe - * lock with a softirq-unsafe lock - to achieve this we search - * the backwards-subgraph starting at , and the - * forwards-subgraph starting at : + * keep state, bit flip the direction and strip read. */ - if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ, - LOCK_ENABLED_SOFTIRQ, "soft")) - return 0; + return state | (dir ^ 2); +} + +static int check_irq_usage(struct task_struct *curr, struct held_lock *prev, + struct held_lock *next, enum lock_usage_bit bit) +{ /* - * Prove that the new dependency does not connect a softirq-safe-read - * lock with a softirq-unsafe lock - to achieve this we search + * Prove that the new dependency does not connect a hardirq-safe + * lock with a hardirq-unsafe lock - to achieve this we search * the backwards-subgraph starting at , and the * forwards-subgraph starting at : */ - if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ_READ, - LOCK_ENABLED_SOFTIRQ, "soft")) + if (!check_usage(curr, prev, next, bit, + exclusive_bit(bit), state_name(bit))) return 0; + bit++; /* _READ */ + /* - * Prove that the new dependency does not connect a reclaim-fs-safe - * lock with a reclaim-fs-unsafe lock - to achieve this we search + * Prove that the new dependency does not connect a hardirq-safe-read + * lock with a hardirq-unsafe lock - to achieve this we search * the backwards-subgraph starting at , and the * forwards-subgraph starting at : */ - if (!check_usage(curr, prev, next, LOCK_USED_IN_RECLAIM_FS, - LOCK_ENABLED_RECLAIM_FS, "reclaim-fs")) + if (!check_usage(curr, prev, next, bit, + exclusive_bit(bit), state_name(bit))) return 0; - /* - * Prove that the new dependency does not connect a reclaim-fs-safe-read - * lock with a reclaim-fs-unsafe lock - to achieve this we search - * the backwards-subgraph starting at , and the - * forwards-subgraph starting at : - */ - if (!check_usage(curr, prev, next, LOCK_USED_IN_RECLAIM_FS_READ, - LOCK_ENABLED_RECLAIM_FS, "reclaim-fs-read")) + return 1; +} + +static int +check_prev_add_irq(struct task_struct *curr, struct held_lock *prev, + struct held_lock *next) +{ +#define LOCKDEP_STATE(__STATE) \ + if (!check_irq_usage(curr, prev, next, LOCK_USED_IN_##__STATE)) \ return 0; +#include "lockdep_states.h" +#undef LOCKDEP_STATE return 1; } @@ -1984,30 +2000,6 @@ static int RECLAIM_FS_verbose(struct lock_class *class) #define STRICT_READ_CHECKS 1 -static const char *state_names[] = { -#define LOCKDEP_STATE(__STATE) \ - STR(__STATE), -#include "lockdep_states.h" -#undef LOCKDEP_STATE -}; - -static inline const char *state_name(enum lock_usage_bit bit) -{ - return state_names[bit >> 2]; -} - -static const char *state_rnames[] = { -#define LOCKDEP_STATE(__STATE) \ - STR(__STATE)"-READ", -#include "lockdep_states.h" -#undef LOCKDEP_STATE -}; - -static inline const char *state_rname(enum lock_usage_bit bit) -{ - return state_rnames[bit >> 2]; -} - static int (*state_verbose_f[])(struct lock_class *class) = { #define LOCKDEP_STATE(__STATE) \ __STATE##_verbose, @@ -2021,37 +2013,12 @@ static inline int state_verbose(enum lock_usage_bit bit, return state_verbose_f[bit >> 2](class); } -static int exclusive_bit(int new_bit) -{ - /* - * USED_IN - * USED_IN_READ - * ENABLED - * ENABLED_READ - * - * bit 0 - write/read - * bit 1 - used_in/enabled - * bit 2+ state - */ - - int state = new_bit & ~3; - int dir = new_bit & 2; - - /* - * keep state, bit flip the direction and strip read. - */ - return state | (dir ^ 2); -} - typedef int (*check_usage_f)(struct task_struct *, struct held_lock *, enum lock_usage_bit bit, const char *name); static int mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit) { - const char *name = state_name(new_bit); - const char *rname = state_rname(new_bit); - int excl_bit = exclusive_bit(new_bit); int read = new_bit & 1; int dir = new_bit & 2; @@ -2078,7 +2045,7 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit) * states. */ if ((!read || !dir || STRICT_READ_CHECKS) && - !usage(curr, this, excl_bit, name)) + !usage(curr, this, excl_bit, state_name(new_bit))) return 0; /* @@ -2089,7 +2056,8 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit) return 0; if (STRICT_READ_CHECKS && - !usage(curr, this, excl_bit + 1, rname)) + !usage(curr, this, excl_bit + 1, + state_name(new_bit + 1))) return 0; }