perfmon: refactor perf metric support
Refactoring perf metric support to remove branching on bundle type in
the dispatch wrapper. This change includes caching the rdpmc index at
perfmon_start(), so that the mmap_page.index doesn't need to be looked
up each time. It also exclude the effects of mmap_page.index.
This patch prepares the path for bundles that support general, fixed and
metrics counters simulataneously.
Type: refactor
Signed-off-by: Ray Kinsella <mdr@ashroe.eu>
Change-Id: I9c5b4917bd02fea960e546e8558452c4362eabc4
diff --git a/src/plugins/perfmon/dispatch_wrapper.c b/src/plugins/perfmon/dispatch_wrapper.c
index 5e53417..64df7f5 100644
--- a/src/plugins/perfmon/dispatch_wrapper.c
+++ b/src/plugins/perfmon/dispatch_wrapper.c
@@ -25,77 +25,41 @@
#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_mmap_read_pmcs (u64 *counters,
- struct perf_event_mmap_page **mmap_pages,
- u8 n_counters)
+perfmon_read_pmcs (u64 *counters, u32 *indexes, u8 n_counters)
{
switch (n_counters)
{
- default:
case 12:
- counters[11] = perfmon_mmap_read_pmc1 (mmap_pages[11]);
+ counters[11] = _rdpmc (indexes[11] - 1);
case 11:
- counters[10] = perfmon_mmap_read_pmc1 (mmap_pages[10]);
+ counters[10] = _rdpmc (indexes[10] - 1);
case 10:
- counters[9] = perfmon_mmap_read_pmc1 (mmap_pages[9]);
+ counters[9] = _rdpmc (indexes[9] - 1);
case 9:
- counters[8] = perfmon_mmap_read_pmc1 (mmap_pages[8]);
+ counters[8] = _rdpmc (indexes[8] - 1);
case 8:
- counters[7] = perfmon_mmap_read_pmc1 (mmap_pages[7]);
+ counters[7] = _rdpmc (indexes[7] - 1);
case 7:
- counters[6] = perfmon_mmap_read_pmc1 (mmap_pages[6]);
+ counters[6] = _rdpmc (indexes[6] - 1);
case 6:
- counters[5] = perfmon_mmap_read_pmc1 (mmap_pages[5]);
+ counters[5] = _rdpmc (indexes[5] - 1);
case 5:
- counters[4] = perfmon_mmap_read_pmc1 (mmap_pages[4]);
+ counters[4] = _rdpmc (indexes[4] - 1);
case 4:
- counters[3] = perfmon_mmap_read_pmc1 (mmap_pages[3]);
+ counters[3] = _rdpmc (indexes[3] - 1);
case 3:
- counters[2] = perfmon_mmap_read_pmc1 (mmap_pages[2]);
+ counters[2] = _rdpmc (indexes[2] - 1);
case 2:
- counters[1] = perfmon_mmap_read_pmc1 (mmap_pages[1]);
+ counters[1] = _rdpmc (indexes[1] - 1);
case 1:
- counters[0] = perfmon_mmap_read_pmc1 (mmap_pages[0]);
- break;
+ counters[0] = _rdpmc (indexes[0] - 1);
}
}
uword
-perfmon_dispatch_wrapper_mmap (vlib_main_t *vm, vlib_node_runtime_t *node,
- vlib_frame_t *frame)
+perfmon_dispatch_wrapper (vlib_main_t *vm, vlib_node_runtime_t *node,
+ vlib_frame_t *frame)
{
perfmon_main_t *pm = &perfmon_main;
perfmon_thread_runtime_t *rt =
@@ -105,15 +69,17 @@
u8 n_events = rt->n_events;
- u64 before[PERF_MAX_EVENTS];
- u64 after[PERF_MAX_EVENTS];
+ struct
+ {
+ u64 t[2][PERF_MAX_EVENTS];
+ } samples;
uword rv;
clib_prefetch_load (s);
- perfmon_mmap_read_pmcs (&before[0], rt->mmap_pages, n_events);
+ perfmon_read_pmcs (&samples.t[0][0], &rt->indexes[0], n_events);
rv = node->function (vm, node, frame);
- perfmon_mmap_read_pmcs (&after[0], rt->mmap_pages, n_events);
+ perfmon_read_pmcs (&samples.t[1][0], &rt->indexes[0], n_events);
if (rv == 0)
return rv;
@@ -122,110 +88,17 @@
s->n_packets += rv;
for (int i = 0; i < n_events; i++)
- s->value[i] += after[i] - before[i];
-
- return rv;
-}
-
-static_always_inline void
-perfmon_metric_read_pmcs (u64 *counters, int *pmc_index, u8 n_counters)
-{
- switch (n_counters)
{
- default:
- case 12:
- counters[11] = _rdpmc (pmc_index[11]);
- case 11:
- counters[10] = _rdpmc (pmc_index[10]);
- case 10:
- counters[9] = _rdpmc (pmc_index[9]);
- case 9:
- counters[8] = _rdpmc (pmc_index[8]);
- case 8:
- counters[7] = _rdpmc (pmc_index[7]);
- 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;
+ 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];
+ }
}
-}
-
-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)
-{
- 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);
-
- u8 n_events = rt->n_events;
-
- u64 before[PERF_MAX_EVENTS];
- int pmc_index[PERF_MAX_EVENTS];
- uword rv;
-
- clib_prefetch_load (s);
-
- switch (n_events)
- {
- default:
- case 12:
- pmc_index[11] = perfmon_metric_index (rt->bundle, 11);
- case 11:
- pmc_index[10] = perfmon_metric_index (rt->bundle, 10);
- case 10:
- pmc_index[9] = perfmon_metric_index (rt->bundle, 9);
- case 9:
- pmc_index[8] = perfmon_metric_index (rt->bundle, 8);
- case 8:
- pmc_index[7] = perfmon_metric_index (rt->bundle, 7);
- case 7:
- pmc_index[6] = perfmon_metric_index (rt->bundle, 6);
- case 6:
- pmc_index[5] = perfmon_metric_index (rt->bundle, 5);
- case 5:
- pmc_index[4] = perfmon_metric_index (rt->bundle, 4);
- case 4:
- pmc_index[3] = perfmon_metric_index (rt->bundle, 3);
- case 3:
- pmc_index[2] = perfmon_metric_index (rt->bundle, 2);
- case 2:
- pmc_index[1] = perfmon_metric_index (rt->bundle, 1);
- case 1:
- pmc_index[0] = perfmon_metric_index (rt->bundle, 0);
- break;
- }
-
- 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_metric_read_pmcs (&s->t[1].value[0], pmc_index, n_events);
-
- if (rv == 0)
- return rv;
-
- s->n_calls += 1;
- s->n_packets += rv;
return rv;
}
diff --git a/src/plugins/perfmon/intel/bundle/topdown_metrics.c b/src/plugins/perfmon/intel/bundle/topdown_metrics.c
index af1c108..a28c4e7 100644
--- a/src/plugins/perfmon/intel/bundle/topdown_metrics.c
+++ b/src/plugins/perfmon/intel/bundle/topdown_metrics.c
@@ -122,16 +122,13 @@
.name = "topdown-level1",
.description = "Top-down Microarchitecture Analysis Level 1",
.source = "intel-core",
- .offset_type = PERFMON_OFFSET_TYPE_METRICS,
.events[0] = INTEL_CORE_E_TOPDOWN_SLOTS,
.events[1] = INTEL_CORE_E_TOPDOWN_L1_RETIRING_METRIC,
.events[2] = INTEL_CORE_E_TOPDOWN_L1_BAD_SPEC_METRIC,
.events[3] = INTEL_CORE_E_TOPDOWN_L1_FE_BOUND_METRIC,
.events[4] = INTEL_CORE_E_TOPDOWN_L1_BE_BOUND_METRIC,
.n_events = 5,
- .metrics[0] = RDPMC_SLOTS | FIXED_COUNTER_SLOTS,
- .metrics[1] = RDPMC_METRICS | METRIC_COUNTER_TOPDOWN_L1_L2,
- .n_metrics = 2,
+ .preserve_samples = 0x1F,
.cpu_supports = topdown_lvl1_cpu_supports,
.n_cpu_supports = ARRAY_LEN (topdown_lvl1_cpu_supports),
.format_fn = format_topdown_lvl1,
@@ -251,7 +248,6 @@
.name = "topdown-level2",
.description = "Top-down Microarchitecture Analysis Level 2",
.source = "intel-core",
- .offset_type = PERFMON_OFFSET_TYPE_METRICS,
.events[0] = INTEL_CORE_E_TOPDOWN_SLOTS,
.events[1] = INTEL_CORE_E_TOPDOWN_L1_RETIRING_METRIC,
.events[2] = INTEL_CORE_E_TOPDOWN_L1_BAD_SPEC_METRIC,
@@ -262,9 +258,7 @@
.events[7] = INTEL_CORE_E_TOPDOWN_L2_FETCHLAT_METRIC,
.events[8] = INTEL_CORE_E_TOPDOWN_L2_MEMBOUND_METRIC,
.n_events = 9,
- .metrics[0] = RDPMC_SLOTS | FIXED_COUNTER_SLOTS,
- .metrics[1] = RDPMC_METRICS | METRIC_COUNTER_TOPDOWN_L1_L2,
- .n_metrics = 2,
+ .preserve_samples = 0x1FF,
.cpu_supports = topdown_lvl2_cpu_supports,
.n_cpu_supports = ARRAY_LEN (topdown_lvl2_cpu_supports),
.format_fn = format_topdown_lvl2,
diff --git a/src/plugins/perfmon/perfmon.c b/src/plugins/perfmon/perfmon.c
index 799659d..0917892 100644
--- a/src/plugins/perfmon/perfmon.c
+++ b/src/plugins/perfmon/perfmon.c
@@ -196,6 +196,7 @@
rt->bundle = b;
rt->n_events = b->n_events;
rt->n_nodes = n_nodes;
+ rt->preserve_samples = b->preserve_samples;
vec_validate_aligned (rt->node_stats, n_nodes - 1,
CLIB_CACHE_LINE_BYTES);
}
@@ -212,6 +213,33 @@
return err;
}
+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;
+}
+
clib_error_t *
perfmon_start (vlib_main_t *vm, perfmon_bundle_t *b)
{
@@ -238,20 +266,28 @@
}
if (b->active_type == PERFMON_BUNDLE_TYPE_NODE)
{
+ 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);
- vlib_node_function_t *funcs[PERFMON_OFFSET_TYPE_MAX];
-#define _(type, pfunc) funcs[type] = pfunc;
+ for (int j = 0; j < b->n_events; j++)
+ {
+ tr->indexes[j] = perfmon_mmap_read_index (tr->mmap_pages[j]);
- foreach_permon_offset_type
-#undef _
-
- ASSERT (funcs[b->offset_type]);
+ /* if a zero index is returned generate error */
+ if (!tr->indexes[j])
+ {
+ perfmon_reset (vm);
+ return clib_error_return (0, "invalid rdpmc index");
+ }
+ }
+ }
for (int i = 0; i < vlib_get_n_threads (); i++)
vlib_node_set_dispatch_wrapper (vlib_get_main_by_index (i),
- funcs[b->offset_type]);
+ perfmon_dispatch_wrapper);
}
-
pm->sample_time = vlib_time_now (vm);
pm->is_running = 1;
diff --git a/src/plugins/perfmon/perfmon.h b/src/plugins/perfmon/perfmon.h
index 0b46e52..5003e59 100644
--- a/src/plugins/perfmon/perfmon.h
+++ b/src/plugins/perfmon/perfmon.h
@@ -49,13 +49,6 @@
} perfmon_bundle_type_flag_t;
-typedef enum
-{
- PERFMON_OFFSET_TYPE_MMAP,
- PERFMON_OFFSET_TYPE_METRICS,
- PERFMON_OFFSET_TYPE_MAX,
-} perfmon_offset_type_t;
-
typedef struct
{
u32 type_from_instance : 1;
@@ -85,12 +78,7 @@
} perfmon_instance_type_t;
struct perfmon_source;
-vlib_node_function_t perfmon_dispatch_wrapper_mmap;
-vlib_node_function_t perfmon_dispatch_wrapper_metrics;
-
-#define foreach_permon_offset_type \
- _ (PERFMON_OFFSET_TYPE_MMAP, perfmon_dispatch_wrapper_mmap) \
- _ (PERFMON_OFFSET_TYPE_METRICS, perfmon_dispatch_wrapper_metrics)
+vlib_node_function_t perfmon_dispatch_wrapper;
typedef clib_error_t *(perfmon_source_init_fn_t) (vlib_main_t *vm,
struct perfmon_source *);
@@ -131,12 +119,10 @@
};
perfmon_bundle_type_t active_type;
- perfmon_offset_type_t offset_type;
u32 events[PERF_MAX_EVENTS];
u32 n_events;
- u32 metrics[PERF_MAX_EVENTS];
- u32 n_metrics;
+ u16 preserve_samples;
perfmon_cpu_supports_t *cpu_supports;
u32 n_cpu_supports;
@@ -180,6 +166,8 @@
u16 n_nodes;
perfmon_node_stats_t *node_stats;
perfmon_bundle_t *bundle;
+ u32 indexes[PERF_MAX_EVENTS];
+ u16 preserve_samples;
struct perf_event_mmap_page *mmap_pages[PERF_MAX_EVENTS];
} perfmon_thread_runtime_t;