From 4fe444dafd2243de56091ab5dd7efa0050b0597f Mon Sep 17 00:00:00 2001 From: Julien Desfossez Date: Tue, 5 Jul 2016 11:50:46 -0400 Subject: [PATCH] Enable perf PMU counters by raw ID MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Allow enabling perf PMU counters by raw ID in addition to the generic list already provided. The format for kernel tracing is "perf:cpu:raw:rNNN:" and "perf:thread:raw:rNNN: for user-space. The rNNN format is the same as perf-record(1) where NNN is a hexadecimal event descriptor in the form of umask+eventsel. The field to associate a clearer name to the counter. Example usage on Intel i7-3520M to get the unhalted reference cycles (eventsel: 0x13c) count at privilege level 0 (umask: 0x00): lttng add-context -k -t perf:cpu:raw:r0013c:x86unhalted Result in the trace: sched_switch: { cpu_id = 3 }, { perf_cpu_raw_r0013c_x86unhalted = 27632578 }, [...] Signed-off-by: Julien Desfossez Signed-off-by: Jérémie Galarneau --- doc/man/lttng-add-context.1.txt | 9 +++ src/bin/lttng/commands/add_context.c | 106 ++++++++++++++++++++++++++- 2 files changed, 114 insertions(+), 1 deletion(-) diff --git a/doc/man/lttng-add-context.1.txt b/doc/man/lttng-add-context.1.txt index f995a7fbe..a1e0fe78f 100644 --- a/doc/man/lttng-add-context.1.txt +++ b/doc/man/lttng-add-context.1.txt @@ -45,6 +45,15 @@ per-thread (`perf:thread:` prefix) counters. Currently, per-CPU counters can only be used in the Linux kernel tracing domain, while per-thread counters can only be used in the user space tracing domain. +It is also possible to enable PMU counters by raw ID using the +`perf:cpu:raw:r:` or `perf:thread:raw:r:` format for +the kernel and user-space respectively. `` is a hexadecimal event +descriptor which is the same format as used by perf-record(1): a +concatenation of the `Umask value` and `Event number` provided by the +processor's manufacturer. The possible values for this field are +processor-specific. The `` field is used to associate a clearer +name to the counter. + Application-specific context fields can be added to a channel using the following syntax: diff --git a/src/bin/lttng/commands/add_context.c b/src/bin/lttng/commands/add_context.c index 2f43dc7ff..5fc65bf55 100644 --- a/src/bin/lttng/commands/add_context.c +++ b/src/bin/lttng/commands/add_context.c @@ -87,6 +87,7 @@ enum perf_type { PERF_TYPE_HARDWARE = 0, PERF_TYPE_SOFTWARE = 1, PERF_TYPE_HW_CACHE = 3, + PERF_TYPE_RAW = 4, }; enum perf_count_hard { @@ -687,10 +688,101 @@ end: return type; } +static +int find_ctx_type_perf_raw(const char *ctx, struct ctx_type *type) +{ + int ret; + int field_pos = 0; + char *tmp_list, *cur_list; + + cur_list = tmp_list = strdup(ctx); + if (!tmp_list) { + PERROR("strdup temp list"); + ret = -ENOMEM; + goto end; + } + + /* Looking for "perf:[cpu|thread]:raw::". */ + for (;;) { + char *next; + + next = strtok(cur_list, ":"); + if (!next) { + break; + } + cur_list = NULL; + switch (field_pos) { + case 0: + if (strncmp(next, "perf", 4) != 0) { + ret = -1; + goto end; + } + break; + case 1: + if (strncmp(next, "cpu", 3) == 0) { + type->opt->ctx_type = CONTEXT_PERF_CPU_COUNTER; + } else if (strncmp(next, "thread", 4) == 0) { + type->opt->ctx_type = CONTEXT_PERF_THREAD_COUNTER; + } else { + ret = -1; + goto end; + } + break; + case 2: + if (strncmp(next, "raw", 3) != 0) { + ret = -1; + goto end; + } + break; + case 3: + { + char *endptr; + + if (strlen(next) < 2 || next[0] != 'r') { + ERR("Wrong perf raw mask format: expected rNNN"); + ret = -1; + goto end; + } + errno = 0; + type->opt->u.perf.config = strtoll(next + 1, &endptr, 16); + if (errno != 0 || !endptr || *endptr) { + ERR("Wrong perf raw mask format: expected rNNN"); + ret = -1; + goto end; + } + break; + } + case 4: + /* name */ + break; + case 5: + ERR("Too many ':' in perf raw format"); + ret = -1; + goto end; + }; + field_pos++; + } + + if (field_pos < 5) { + ERR("Invalid perf counter specifier, expected a specifier of " + "the form perf:cpu:raw:rNNN: or " + "perf:thread:raw:rNNN:"); + ret = -1; + goto end; + } + + ret = 0; + goto end; + +end: + free(tmp_list); + return ret; +} + static struct ctx_type *get_context_type(const char *ctx) { - int opt_index; + int opt_index, ret; struct ctx_type *type = NULL; const char app_ctx_prefix[] = "$app."; char *provider_name = NULL, *ctx_name = NULL; @@ -713,6 +805,18 @@ struct ctx_type *get_context_type(const char *ctx) goto found; } + /* Check if ctx is a raw perf context. */ + ret = find_ctx_type_perf_raw(ctx, type); + if (ret == 0) { + type->opt->u.perf.type = PERF_TYPE_RAW; + type->opt->symbol = strdup(ctx); + if (!type->opt->symbol) { + PERROR("Copy perf field name"); + goto not_found; + } + goto found; + } + /* * No match found against static contexts; check if it is an app * context. -- 2.34.1