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Diffstat (limited to 'src/plugins/perfmon/intel/dispatch_wrapper.c')
| -rw-r--r-- | src/plugins/perfmon/intel/dispatch_wrapper.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/src/plugins/perfmon/intel/dispatch_wrapper.c b/src/plugins/perfmon/intel/dispatch_wrapper.c new file mode 100644 index 00000000000..d424b54b85f --- /dev/null +++ b/src/plugins/perfmon/intel/dispatch_wrapper.c @@ -0,0 +1,160 @@ +/* + * Copyright (c) 2020 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "vppinfra/string.h" +#include <vnet/vnet.h> + +#include <vlibapi/api.h> +#include <vlibmemory/api.h> +#include <vnet/plugin/plugin.h> +#include <vpp/app/version.h> +#include <linux/limits.h> +#include <sys/ioctl.h> + +#include <perfmon/perfmon.h> + +vlib_node_function_t *perfmon_dispatch_wrappers[PERF_MAX_EVENTS + 1]; + +static_always_inline void +perfmon_read_pmcs (u64 *counters, u32 *indexes, u8 n_counters) +{ + for (int i = 0; i < n_counters; i++) + counters[i] = _rdpmc (indexes[i] - 1); +} + +static_always_inline uword +perfmon_dispatch_wrapper_inline (vlib_main_t *vm, vlib_node_runtime_t *node, + vlib_frame_t *frame, u8 n_events) +{ + perfmon_main_t *pm = &perfmon_main; + perfmon_thread_runtime_t *rt = + vec_elt_at_index (pm->thread_runtimes, vm->thread_index); + perfmon_node_stats_t *s = + vec_elt_at_index (rt->node_stats, node->node_index); + + struct + { + u64 t[2][PERF_MAX_EVENTS]; + } samples; + uword rv; + + clib_prefetch_load (s); + + perfmon_read_pmcs (&samples.t[0][0], &rt->indexes[0], n_events); + rv = node->function (vm, node, frame); + perfmon_read_pmcs (&samples.t[1][0], &rt->indexes[0], n_events); + + if (rv == 0) + return rv; + + s->n_calls += 1; + s->n_packets += rv; + + for (int i = 0; i < n_events; i++) + { + if (!(rt->preserve_samples & 1 << i)) + { + s->value[i] += samples.t[1][i] - samples.t[0][i]; + } + else + { + s->t[0].value[i] = samples.t[0][i]; + s->t[1].value[i] = samples.t[1][i]; + } + } + + return rv; +} + +static_always_inline u32 +perfmon_mmap_read_index (const struct perf_event_mmap_page *mmap_page) +{ + u32 idx; + 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 + { + seq = mmap_page->lock; + CLIB_COMPILER_BARRIER (); + + idx = mmap_page->index; + + CLIB_COMPILER_BARRIER (); + } + while (mmap_page->lock != seq); + + return idx; +} + +static_always_inline clib_error_t * +read_mmap_indexes (perfmon_bundle_t *b) +{ + perfmon_main_t *pm = &perfmon_main; + for (int i = 0; i < vec_len (pm->thread_runtimes); i++) + { + perfmon_thread_runtime_t *tr; + tr = vec_elt_at_index (pm->thread_runtimes, i); + + for (int j = 0; j < b->n_events; j++) + { + tr->indexes[j] = perfmon_mmap_read_index (tr->mmap_pages[j]); + + /* if a zero index is returned generate error */ + if (!tr->indexes[j]) + { + return clib_error_return (0, "invalid rdpmc index"); + } + } + } + return 0; +} + +clib_error_t * +intel_config_dispatch_wrapper (perfmon_bundle_t *b, + vlib_node_function_t **dispatch_wrapper) +{ + clib_error_t *err = 0; + if ((err = read_mmap_indexes (b)) != 0) + return err; + + (*dispatch_wrapper) = perfmon_dispatch_wrappers[b->n_events]; + return 0; +} + +#define foreach_n_events \ + _ (1) _ (2) _ (3) _ (4) _ (5) _ (6) _ (7) _ (8) _ (9) _ (10) _ (11) _ (12) + +#define _(x) \ + static uword perfmon_dispatch_wrapper##x ( \ + vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame) \ + { \ + return perfmon_dispatch_wrapper_inline (vm, node, frame, x); \ + } + +foreach_n_events +#undef _ + + vlib_node_function_t *perfmon_dispatch_wrappers[PERF_MAX_EVENTS + 1] = { +#define _(x) [x] = &perfmon_dispatch_wrapper##x, + foreach_n_events +#undef _ + }; |