diff options
Diffstat (limited to 'tools/perf/util/bpf_skel/lock_contention.bpf.c')
| -rw-r--r-- | tools/perf/util/bpf_skel/lock_contention.bpf.c | 104 |
1 files changed, 95 insertions, 9 deletions
diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c index ad0ca5d50557..e6007eaeda1a 100644 --- a/tools/perf/util/bpf_skel/lock_contention.bpf.c +++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c @@ -10,6 +10,14 @@ /* default buffer size */ #define MAX_ENTRIES 10240 +/* lock contention flags from include/trace/events/lock.h */ +#define LCB_F_SPIN (1U << 0) +#define LCB_F_READ (1U << 1) +#define LCB_F_WRITE (1U << 2) +#define LCB_F_RT (1U << 3) +#define LCB_F_PERCPU (1U << 4) +#define LCB_F_MUTEX (1U << 5) + struct tstamp_data { __u64 timestamp; __u64 lock; @@ -76,13 +84,23 @@ struct { __uint(max_entries, 1); } addr_filter SEC(".maps"); +struct rw_semaphore___old { + struct task_struct *owner; +} __attribute__((preserve_access_index)); + +struct rw_semaphore___new { + atomic_long_t owner; +} __attribute__((preserve_access_index)); + /* control flags */ int enabled; int has_cpu; int has_task; int has_type; int has_addr; +int needs_callstack; int stack_skip; +int lock_owner; /* determine the key of lock stat */ int aggr_mode; @@ -131,17 +149,59 @@ static inline int can_record(u64 *ctx) return 1; } -static inline void update_task_data(__u32 pid) +static inline int update_task_data(struct task_struct *task) { struct contention_task_data *p; + int pid, err; + + err = bpf_core_read(&pid, sizeof(pid), &task->pid); + if (err) + return -1; p = bpf_map_lookup_elem(&task_data, &pid); if (p == NULL) { - struct contention_task_data data; + struct contention_task_data data = {}; - bpf_get_current_comm(data.comm, sizeof(data.comm)); + BPF_CORE_READ_STR_INTO(&data.comm, task, comm); bpf_map_update_elem(&task_data, &pid, &data, BPF_NOEXIST); } + + return 0; +} + +#ifndef __has_builtin +# define __has_builtin(x) 0 +#endif + +static inline struct task_struct *get_lock_owner(__u64 lock, __u32 flags) +{ + struct task_struct *task; + __u64 owner = 0; + + if (flags & LCB_F_MUTEX) { + struct mutex *mutex = (void *)lock; + owner = BPF_CORE_READ(mutex, owner.counter); + } else if (flags == LCB_F_READ || flags == LCB_F_WRITE) { +#if __has_builtin(bpf_core_type_matches) + if (bpf_core_type_matches(struct rw_semaphore___old)) { + struct rw_semaphore___old *rwsem = (void *)lock; + owner = (unsigned long)BPF_CORE_READ(rwsem, owner); + } else if (bpf_core_type_matches(struct rw_semaphore___new)) { + struct rw_semaphore___new *rwsem = (void *)lock; + owner = BPF_CORE_READ(rwsem, owner.counter); + } +#else + /* assume new struct */ + struct rw_semaphore *rwsem = (void *)lock; + owner = BPF_CORE_READ(rwsem, owner.counter); +#endif + } + + if (!owner) + return NULL; + + task = (void *)(owner & ~7UL); + return task; } SEC("tp_btf/contention_begin") @@ -173,11 +233,31 @@ int contention_begin(u64 *ctx) pelem->lock = (__u64)ctx[0]; pelem->flags = (__u32)ctx[1]; - if (aggr_mode == LOCK_AGGR_CALLER) { + if (needs_callstack) { pelem->stack_id = bpf_get_stackid(ctx, &stacks, BPF_F_FAST_STACK_CMP | stack_skip); if (pelem->stack_id < 0) lost++; + } else if (aggr_mode == LOCK_AGGR_TASK) { + struct task_struct *task; + + if (lock_owner) { + task = get_lock_owner(pelem->lock, pelem->flags); + + /* The flags is not used anymore. Pass the owner pid. */ + if (task) + pelem->flags = BPF_CORE_READ(task, pid); + else + pelem->flags = -1U; + + } else { + task = bpf_get_current_task_btf(); + } + + if (task) { + if (update_task_data(task) < 0 && lock_owner) + pelem->flags = -1U; + } } return 0; @@ -188,7 +268,7 @@ int contention_end(u64 *ctx) { __u32 pid; struct tstamp_data *pelem; - struct contention_key key; + struct contention_key key = {}; struct contention_data *data; __u64 duration; @@ -204,14 +284,20 @@ int contention_end(u64 *ctx) switch (aggr_mode) { case LOCK_AGGR_CALLER: - key.aggr_key = pelem->stack_id; + key.stack_id = pelem->stack_id; break; case LOCK_AGGR_TASK: - key.aggr_key = pid; - update_task_data(pid); + if (lock_owner) + key.pid = pelem->flags; + else + key.pid = pid; + if (needs_callstack) + key.stack_id = pelem->stack_id; break; case LOCK_AGGR_ADDR: - key.aggr_key = pelem->lock; + key.lock_addr = pelem->lock; + if (needs_callstack) + key.stack_id = pelem->stack_id; break; default: /* should not happen */ |