#include #include #include #include #define CREATE_TRACE_POINTS #include "trace_benchmark.h" static struct task_struct *bm_event_thread; static char bm_str[BENCHMARK_EVENT_STRLEN] = "START"; static u64 bm_total; static u64 bm_totalsq; static u64 bm_last; static u64 bm_max; static u64 bm_min; static u64 bm_first; static u64 bm_cnt; static u64 bm_stddev; static unsigned int bm_avg; static unsigned int bm_std; static bool ok_to_run; /* * This gets called in a loop recording the time it took to write * the tracepoint. What it writes is the time statistics of the last * tracepoint write. As there is nothing to write the first time * it simply writes "START". As the first write is cold cache and * the rest is hot, we save off that time in bm_first and it is * reported as "first", which is shown in the second write to the * tracepoint. The "first" field is writen within the statics from * then on but never changes. */ static void trace_do_benchmark(void) { u64 start; u64 stop; u64 delta; u64 stddev; u64 seed; u64 last_seed; unsigned int avg; unsigned int std = 0; /* Only run if the tracepoint is actually active */ if (!trace_benchmark_event_enabled() || !tracing_is_on()) return; local_irq_disable(); start = trace_clock_local(); trace_benchmark_event(bm_str); stop = trace_clock_local(); local_irq_enable(); bm_cnt++; delta = stop - start; /* * The first read is cold cached, keep it separate from the * other calculations. */ if (bm_cnt == 1) { bm_first = delta; scnprintf(bm_str, BENCHMARK_EVENT_STRLEN, "first=%llu [COLD CACHED]", bm_first); return; } bm_last = delta; if (delta > bm_max) bm_max = delta; if (!bm_min || delta < bm_min) bm_min = delta; /* * When bm_cnt is greater than UINT_MAX, it breaks the statistics * accounting. Freeze the statistics when that happens. * We should have enough data for the avg and stddev anyway. */ if (bm_cnt > UINT_MAX) { scnprintf(bm_str, BENCHMARK_EVENT_STRLEN, "last=%llu first=%llu max=%llu min=%llu ** avg=%u std=%d std^2=%lld", bm_last, bm_first, bm_max, bm_min, bm_avg, bm_std, bm_stddev); return; } bm_total += delta; bm_totalsq += delta * delta; if (bm_cnt > 1) { /* * Apply Welford's method to calculate standard deviation: * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) */ stddev = (u64)bm_cnt * bm_totalsq - bm_total * bm_total; do_div(stddev, (u32)bm_cnt); do_div(stddev, (u32)bm_cnt - 1); } else stddev = 0; delta = bm_total; do_div(delta, bm_cnt); avg = delta; if (stddev > 0) { int i = 0; /* * stddev is the square of standard deviation but * we want the actualy number. Use the average * as our seed to find the std. * * The next try is: * x = (x + N/x) / 2 * * Where N is the squared number to find the square * root of. */ seed = avg; do { last_seed = seed; seed = stddev; if (!last_seed) break; do_div(seed, last_seed); seed += last_seed; do_div(seed, 2); } while (i++ < 10 && last_seed != seed); std = seed; } scnprintf(bm_str, BENCHMARK_EVENT_STRLEN, "last=%llu first=%llu max=%llu min=%llu avg=%u std=%d std^2=%lld", bm_last, bm_first, bm_max, bm_min, avg, std, stddev); bm_std = std; bm_avg = avg; bm_stddev = stddev; } static int benchmark_event_kthread(void *arg) { /* sleep a bit to make sure the tracepoint gets activated */ msleep(100); while (!kthread_should_stop()) { trace_do_benchmark(); /* * We don't go to sleep, but let others * run as well. */ cond_resched(); } return 0; } /* * When the benchmark tracepoint is enabled, it calls this * function and the thread that calls the tracepoint is created. */ int trace_benchmark_reg(void) { if (!ok_to_run) { pr_warning("trace benchmark cannot be started via kernel command line\n"); return -EBUSY; } bm_event_thread = kthread_run(benchmark_event_kthread, NULL, "event_benchmark"); if (!bm_event_thread) { pr_warning("trace benchmark failed to create kernel thread\n"); return -ENOMEM; } return 0; } /* * When the benchmark tracepoint is disabled, it calls this * function and the thread that calls the tracepoint is deleted * and all the numbers are reset. */ void trace_benchmark_unreg(void) { if (!bm_event_thread) return; kthread_stop(bm_event_thread); bm_event_thread = NULL; strcpy(bm_str, "START"); bm_total = 0; bm_totalsq = 0; bm_last = 0; bm_max = 0; bm_min = 0; bm_cnt = 0; /* These don't need to be reset but reset them anyway */ bm_first = 0; bm_std = 0; bm_avg = 0; bm_stddev = 0; } static __init int ok_to_run_trace_benchmark(void) { ok_to_run = true; return 0; } early_initcall(ok_to_run_trace_benchmark); lue='2'>stat only
authorDavid S. Miller <davem@davemloft.net>2017-01-30 15:55:48 -0500
committerDavid S. Miller <davem@davemloft.net>2017-01-30 15:56:40 -0500
commit1930b60352e7e195f55b27cde15d2a8f43342a8b (patch)
treeec3f66cd8d8110bf7b4f61e0446bdea505915db9 /tools/perf/pmu-events/arch/x86/broadwell
parent4be9993493bc7ee3fdf950a83bc050a3e6cf2a45 (diff)
parentec960de61503ef349588dccfa3ae02efabcc2762 (diff)
Merge branch 'dsa-port-mirroring'
Florian Fainelli says: ==================== net: dsa: Port mirroring support This patch series adds support for port mirroring in the two Broadcom switch drivers. The major part of the functional are actually with the plumbing between tc and the drivers. Changes in v5: - Added Jiri's Reviewed-by tag to first patch - rebase against latest net-next/master after bcm_sf2 CFP series Changes in v4: - rebased against latest net-next/master after Vivien's changes Changes in v3: - removed multiline comments from added structures - simplify error handling in dsa_slave_add_cls_matchall Changes in v2: - fixed filter removal logic to disable the ingress or egress mirroring when there are no longer ports being monitored in ingress or egress - removed a stray list_head in dsa_port structure that is not used Tested using the two iproute2 examples: tc qdisc add dev eth1 handle ffff: ingress tc filter add dev eth1 parent ffff: \ matchall skip_sw \ action mirred egress mirror \ dev eth2 tc qdisc add dev eth1 handle 1: root prio tc filter add dev eth1 parent 1: \ matchall skip_sw \ action mirred egress mirror \ dev eth2 ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools/perf/pmu-events/arch/x86/broadwell')