#include #include #include #include "../../perf.h" #include #include "../../util/debug.h" #include "../../util/tsc.h" int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc, struct perf_tsc_conversion *tc) { bool cap_user_time_zero; u32 seq; int i = 0; while (1) { seq = pc->lock; rmb(); tc->time_mult = pc->time_mult; tc->time_shift = pc->time_shift; tc->time_zero = pc->time_zero; cap_user_time_zero = pc->cap_user_time_zero; rmb(); if (pc->lock == seq && !(seq & 1)) break; if (++i > 10000) { pr_debug("failed to get perf_event_mmap_page lock\n"); return -EINVAL; } } if (!cap_user_time_zero) return -EOPNOTSUPP; return 0; } u64 rdtsc(void) { unsigned int low, high; asm volatile("rdtsc" : "=a" (low), "=d" (high)); return low | ((u64)high) << 32; } int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc, struct perf_tool *tool, perf_event__handler_t process, struct machine *machine) { union perf_event event = { .time_conv = { .header = { .type = PERF_RECORD_TIME_CONV, .size = sizeof(struct time_conv_event), }, }, }; struct perf_tsc_conversion tc; int err; if (!pc) return 0; err = perf_read_tsc_conversion(pc, &tc); if (err == -EOPNOTSUPP) return 0; if (err) return err; pr_debug2("Synthesizing TSC conversion information\n"); event.time_conv.time_mult = tc.time_mult; event.time_conv.time_shift = tc.time_shift; event.time_conv.time_zero = tc.time_zero; return process(tool, &event, NULL, machine); } 1'>refslogtreecommitdiff
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