diff options
| -rw-r--r-- | src/plugins/perfmon/dispatch_wrapper.c | 121 |
1 files changed, 76 insertions, 45 deletions
diff --git a/src/plugins/perfmon/dispatch_wrapper.c b/src/plugins/perfmon/dispatch_wrapper.c index fe0a449df99..f5972f667a2 100644 --- a/src/plugins/perfmon/dispatch_wrapper.c +++ b/src/plugins/perfmon/dispatch_wrapper.c @@ -25,42 +25,64 @@ #include <perfmon/perfmon.h> +static_always_inline u64 +perfmon_mmap_read_pmc1 (const struct perf_event_mmap_page *mmap_page) +{ + u64 count; + u32 seq; + + /* See documentation in /usr/include/linux/perf_event.h, for more details + * but the 2 main important things are: + * 1) if seq != mmap_page->lock, it means the kernel is currently updating + * the user page and we need to read it again + * 2) if idx == 0, it means the perf event is currently turned off and we + * just need to read the kernel-updated 'offset', otherwise we must also + * add the current hw value (hence rdmpc) */ + do + { + u32 idx; + + seq = mmap_page->lock; + CLIB_COMPILER_BARRIER (); + + idx = mmap_page->index; + count = mmap_page->offset; + if (idx) + count += _rdpmc (idx - 1); + + CLIB_COMPILER_BARRIER (); + } + while (mmap_page->lock != seq); + + return count; +} + static_always_inline void -perfmon_read_pmcs (u64 *counters, int *pmc_index, u8 n_counters) +perfmon_mmap_read_pmcs (u64 *counters, + struct perf_event_mmap_page **mmap_pages, + u8 n_counters) { switch (n_counters) { default: case 7: - counters[6] = _rdpmc (pmc_index[6]); + counters[6] = perfmon_mmap_read_pmc1 (mmap_pages[6]); case 6: - counters[5] = _rdpmc (pmc_index[5]); + counters[5] = perfmon_mmap_read_pmc1 (mmap_pages[5]); case 5: - counters[4] = _rdpmc (pmc_index[4]); + counters[4] = perfmon_mmap_read_pmc1 (mmap_pages[4]); case 4: - counters[3] = _rdpmc (pmc_index[3]); + counters[3] = perfmon_mmap_read_pmc1 (mmap_pages[3]); case 3: - counters[2] = _rdpmc (pmc_index[2]); + counters[2] = perfmon_mmap_read_pmc1 (mmap_pages[2]); case 2: - counters[1] = _rdpmc (pmc_index[1]); + counters[1] = perfmon_mmap_read_pmc1 (mmap_pages[1]); case 1: - counters[0] = _rdpmc (pmc_index[0]); + counters[0] = perfmon_mmap_read_pmc1 (mmap_pages[0]); break; } } -static_always_inline int -perfmon_calc_mmap_offset (perfmon_thread_runtime_t *tr, u8 i) -{ - return (int) (tr->mmap_pages[i]->index + tr->mmap_pages[i]->offset); -} - -static_always_inline int -perfmon_metric_index (perfmon_bundle_t *b, u8 i) -{ - return (int) (b->metrics[i]); -} - uword perfmon_dispatch_wrapper_mmap (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame) @@ -75,34 +97,13 @@ perfmon_dispatch_wrapper_mmap (vlib_main_t *vm, vlib_node_runtime_t *node, u64 before[PERF_MAX_EVENTS]; u64 after[PERF_MAX_EVENTS]; - int pmc_index[PERF_MAX_EVENTS]; uword rv; clib_prefetch_load (s); - switch (n_events) - { - default: - case 7: - pmc_index[6] = perfmon_calc_mmap_offset (rt, 6); - case 6: - pmc_index[5] = perfmon_calc_mmap_offset (rt, 5); - case 5: - pmc_index[4] = perfmon_calc_mmap_offset (rt, 4); - case 4: - pmc_index[3] = perfmon_calc_mmap_offset (rt, 3); - case 3: - pmc_index[2] = perfmon_calc_mmap_offset (rt, 2); - case 2: - pmc_index[1] = perfmon_calc_mmap_offset (rt, 1); - case 1: - pmc_index[0] = perfmon_calc_mmap_offset (rt, 0); - break; - } - - perfmon_read_pmcs (&before[0], pmc_index, n_events); + perfmon_mmap_read_pmcs (&before[0], rt->mmap_pages, n_events); rv = node->function (vm, node, frame); - perfmon_read_pmcs (&after[0], pmc_index, n_events); + perfmon_mmap_read_pmcs (&after[0], rt->mmap_pages, n_events); if (rv == 0) return rv; @@ -116,6 +117,36 @@ perfmon_dispatch_wrapper_mmap (vlib_main_t *vm, vlib_node_runtime_t *node, return rv; } +static_always_inline void +perfmon_metric_read_pmcs (u64 *counters, int *pmc_index, u8 n_counters) +{ + switch (n_counters) + { + default: + case 7: + counters[6] = _rdpmc (pmc_index[6]); + case 6: + counters[5] = _rdpmc (pmc_index[5]); + case 5: + counters[4] = _rdpmc (pmc_index[4]); + case 4: + counters[3] = _rdpmc (pmc_index[3]); + case 3: + counters[2] = _rdpmc (pmc_index[2]); + case 2: + counters[1] = _rdpmc (pmc_index[1]); + case 1: + counters[0] = _rdpmc (pmc_index[0]); + break; + } +} + +static_always_inline int +perfmon_metric_index (perfmon_bundle_t *b, u8 i) +{ + return (int) (b->metrics[i]); +} + uword perfmon_dispatch_wrapper_metrics (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame) @@ -154,11 +185,11 @@ perfmon_dispatch_wrapper_metrics (vlib_main_t *vm, vlib_node_runtime_t *node, break; } - perfmon_read_pmcs (&before[0], pmc_index, n_events); + perfmon_metric_read_pmcs (&before[0], pmc_index, n_events); rv = node->function (vm, node, frame); clib_memcpy_fast (&s->t[0].value[0], &before, sizeof (before)); - perfmon_read_pmcs (&s->t[1].value[0], pmc_index, n_events); + perfmon_metric_read_pmcs (&s->t[1].value[0], pmc_index, n_events); if (rv == 0) return rv; |