cregit-Linux how code gets into the kernel

Release 4.10 tools/perf/arch/x86/util/tsc.c

#include <stdbool.h>
#include <errno.h>

#include <linux/perf_event.h>

#include "../../perf.h"
#include <linux/types.h>
#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; }

Contributors

PersonTokensPropCommitsCommitProp
adrian hunteradrian hunter11796.69%150.00%
peter zijlstrapeter zijlstra43.31%150.00%
Total121100.00%2100.00%


u64 rdtsc(void) { unsigned int low, high; asm volatile("rdtsc" : "=a" (low), "=d" (high)); return low | ((u64)high) << 32; }

Contributors

PersonTokensPropCommitsCommitProp
adrian hunteradrian hunter28100.00%1100.00%
Total28100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
adrian hunteradrian hunter13694.44%150.00%
wang nanwang nan85.56%150.00%
Total144100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
adrian hunteradrian hunter30195.86%457.14%
wang nanwang nan82.55%114.29%
peter zijlstrapeter zijlstra41.27%114.29%
borislav petkovborislav petkov10.32%114.29%
Total314100.00%7100.00%
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