#ifndef __PERF_STATS_H #define __PERF_STATS_H #include #include #include "xyarray.h" struct stats { double n, mean, M2; u64 max, min; }; enum perf_stat_evsel_id { PERF_STAT_EVSEL_ID__NONE = 0, PERF_STAT_EVSEL_ID__CYCLES_IN_TX, PERF_STAT_EVSEL_ID__TRANSACTION_START, PERF_STAT_EVSEL_ID__ELISION_START, PERF_STAT_EVSEL_ID__CYCLES_IN_TX_CP, PERF_STAT_EVSEL_ID__TOPDOWN_TOTAL_SLOTS, PERF_STAT_EVSEL_ID__TOPDOWN_SLOTS_ISSUED, PERF_STAT_EVSEL_ID__TOPDOWN_SLOTS_RETIRED, PERF_STAT_EVSEL_ID__TOPDOWN_FETCH_BUBBLES, PERF_STAT_EVSEL_ID__TOPDOWN_RECOVERY_BUBBLES, PERF_STAT_EVSEL_ID__MAX, }; struct perf_stat_evsel { struct stats res_stats[3]; enum perf_stat_evsel_id id; }; enum aggr_mode { AGGR_NONE, AGGR_GLOBAL, AGGR_SOCKET, AGGR_CORE, AGGR_THREAD, AGGR_UNSET, }; struct perf_stat_config { enum aggr_mode aggr_mode; bool scale; FILE *output; unsigned int interval; }; void update_stats(struct stats *stats, u64 val); double avg_stats(struct stats *stats); double stddev_stats(struct stats *stats); double rel_stddev_stats(double stddev, double avg); static inline void init_stats(struct stats *stats) { stats->n = 0.0; stats->mean = 0.0; stats->M2 = 0.0; stats->min = (u64) -1; stats->max = 0; } struct perf_evsel; struct perf_evlist; bool __perf_evsel_stat__is(struct perf_evsel *evsel, enum perf_stat_evsel_id id); #define perf_stat_evsel__is(evsel, id) \ __perf_evsel_stat__is(evsel, PERF_STAT_EVSEL_ID__ ## id) void perf_stat_evsel_id_init(struct perf_evsel *evsel); extern struct stats walltime_nsecs_stats; typedef void (*print_metric_t)(void *ctx, const char *color, const char *unit, const char *fmt, double val); typedef void (*new_line_t )(void *ctx); void perf_stat__init_shadow_stats(void); void perf_stat__reset_shadow_stats(void); void perf_stat__update_shadow_stats(struct perf_evsel *counter, u64 *count, int cpu); struct perf_stat_output_ctx { void *ctx; print_metric_t print_metric; new_line_t new_line; }; void perf_stat__print_shadow_stats(struct perf_evsel *evsel, double avg, int cpu, struct perf_stat_output_ctx *out); int perf_evlist__alloc_stats(struct perf_evlist *evlist, bool alloc_raw); void perf_evlist__free_stats(struct perf_evlist *evlist); void perf_evlist__reset_stats(struct perf_evlist *evlist); int perf_stat_process_counter(struct perf_stat_config *config, struct perf_evsel *counter); struct perf_tool; union perf_event; struct perf_session; int perf_event__process_stat_event(struct perf_tool *tool, union perf_event *event, struct perf_session *session); size_t perf_event__fprintf_stat(union perf_event *event, FILE *fp); size_t perf_event__fprintf_stat_round(union perf_event *event, FILE *fp); size_t perf_event__fprintf_stat_config(union perf_event *event, FILE *fp); #endif i/linux/net-next.git/commit/?h=nds-private-remove&id=966d2b04e070bc040319aaebfec09e0144dc3341'>root/include/uapi
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authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /include/uapi
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'include/uapi')