lockdep: shrink held_lock structure
struct held_lock {
u64 prev_chain_key; /* 0 8 */
struct lock_class * class; /* 8 8 */
long unsigned int acquire_ip; /* 16 8 */
struct lockdep_map * instance; /* 24 8 */
int irq_context; /* 32 4 */
int trylock; /* 36 4 */
int read; /* 40 4 */
int check; /* 44 4 */
int hardirqs_off; /* 48 4 */
/* size: 56, cachelines: 1 */
/* padding: 4 */
/* last cacheline: 56 bytes */
};
struct held_lock {
u64 prev_chain_key; /* 0 8 */
long unsigned int acquire_ip; /* 8 8 */
struct lockdep_map * instance; /* 16 8 */
unsigned int class_idx:11; /* 24:21 4 */
unsigned int irq_context:2; /* 24:19 4 */
unsigned int trylock:1; /* 24:18 4 */
unsigned int read:2; /* 24:16 4 */
unsigned int check:2; /* 24:14 4 */
unsigned int hardirqs_off:1; /* 24:13 4 */
/* size: 32, cachelines: 1 */
/* padding: 4 */
/* bit_padding: 13 bits */
/* last cacheline: 32 bytes */
};
[mingo@elte.hu: shrunk hlock->class too]
[peterz@infradead.org: fixup bit sizes]
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index f270ce1..b49bfa8 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -190,6 +190,9 @@
u64 chain_key;
};
+#define MAX_LOCKDEP_KEYS_BITS 11
+#define MAX_LOCKDEP_KEYS (1UL << MAX_LOCKDEP_KEYS_BITS)
+
struct held_lock {
/*
* One-way hash of the dependency chain up to this point. We
@@ -206,14 +209,13 @@
* with zero), here we store the previous hash value:
*/
u64 prev_chain_key;
- struct lock_class *class;
unsigned long acquire_ip;
struct lockdep_map *instance;
-
#ifdef CONFIG_LOCK_STAT
u64 waittime_stamp;
u64 holdtime_stamp;
#endif
+ unsigned int class_idx:MAX_LOCKDEP_KEYS_BITS;
/*
* The lock-stack is unified in that the lock chains of interrupt
* contexts nest ontop of process context chains, but we 'separate'
@@ -227,11 +229,11 @@
* The following field is used to detect when we cross into an
* interrupt context:
*/
- int irq_context;
- int trylock;
- int read;
- int check;
- int hardirqs_off;
+ unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
+ unsigned int trylock:1;
+ unsigned int read:2; /* see lock_acquire() comment */
+ unsigned int check:2; /* see lock_acquire() comment */
+ unsigned int hardirqs_off:1;
};
/*