From c7ea8487b97b4552a9fcf214a45e104c5f771c85 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Sat, 13 Jun 2015 11:27:07 +0200 Subject: [PATCH] Implement cpu_id context for filtering Signed-off-by: Mathieu Desnoyers --- include/lttng/ust-abi.h | 1 + include/lttng/ust-events.h | 1 + liblttng-ust/Makefile.am | 1 + liblttng-ust/lttng-context-cpu-id.c | 93 +++++++++++++++++++++++++++++ liblttng-ust/lttng-context.c | 4 ++ liblttng-ust/lttng-events.c | 2 + 6 files changed, 102 insertions(+) create mode 100644 liblttng-ust/lttng-context-cpu-id.c diff --git a/include/lttng/ust-abi.h b/include/lttng/ust-abi.h index d9be9939..232a9b90 100644 --- a/include/lttng/ust-abi.h +++ b/include/lttng/ust-abi.h @@ -139,6 +139,7 @@ enum lttng_ust_context_type { LTTNG_UST_CONTEXT_PROCNAME = 3, LTTNG_UST_CONTEXT_IP = 4, LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER = 5, + LTTNG_UST_CONTEXT_CPU_ID = 6, }; struct lttng_ust_perf_counter_ctx { diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h index 3d7a2747..b34c9d1b 100644 --- a/include/lttng/ust-events.h +++ b/include/lttng/ust-events.h @@ -599,6 +599,7 @@ int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx); int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx); int lttng_add_procname_to_ctx(struct lttng_ctx **ctx); int lttng_add_ip_to_ctx(struct lttng_ctx **ctx); +int lttng_add_cpu_id_to_ctx(struct lttng_ctx **ctx); void lttng_context_vtid_reset(void); void lttng_context_vpid_reset(void); diff --git a/liblttng-ust/Makefile.am b/liblttng-ust/Makefile.am index 442b0540..199fa03d 100644 --- a/liblttng-ust/Makefile.am +++ b/liblttng-ust/Makefile.am @@ -26,6 +26,7 @@ liblttng_ust_runtime_la_SOURCES = \ lttng-context-pthread-id.c \ lttng-context-procname.c \ lttng-context-ip.c \ + lttng-context-cpu-id.c \ lttng-context.c \ lttng-events.c \ lttng-filter.c \ diff --git a/liblttng-ust/lttng-context-cpu-id.c b/liblttng-ust/lttng-context-cpu-id.c new file mode 100644 index 00000000..fb6e407c --- /dev/null +++ b/liblttng-ust/lttng-context-cpu-id.c @@ -0,0 +1,93 @@ +/* + * lttng-context-cpu-id.c + * + * LTTng UST CPU id context. + * + * Note: threads can be migrated at any point while executing the + * tracepoint probe. This means the CPU id field (and filter) is only + * statistical. For instance, even though a user might select a + * cpu_id==1 filter, there may be few events recorded into the channel + * appearing from other CPUs, due to migration. + * + * Copyright (C) 2009-2015 Mathieu Desnoyers + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; only + * version 2.1 of the License. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include "../libringbuffer/getcpu.h" + +static +size_t cpu_id_get_size(size_t offset) +{ + size_t size = 0; + + size += lib_ring_buffer_align(offset, lttng_alignof(int)); + size += sizeof(int); + return size; +} + +static +void cpu_id_record(struct lttng_ctx_field *field, + struct lttng_ust_lib_ring_buffer_ctx *ctx, + struct lttng_channel *chan) +{ + int cpu; + + cpu = lttng_ust_get_cpu(); + lib_ring_buffer_align_ctx(ctx, lttng_alignof(cpu)); + chan->ops->event_write(ctx, &cpu, sizeof(cpu)); +} + +static +void cpu_id_get_value(struct lttng_ctx_field *field, + union lttng_ctx_value *value) +{ + int cpu; + + cpu = lttng_ust_get_cpu(); + value->s64 = cpu; +} + +int lttng_add_cpu_id_to_ctx(struct lttng_ctx **ctx) +{ + struct lttng_ctx_field *field; + + field = lttng_append_context(ctx); + if (!field) + return -ENOMEM; + if (lttng_find_context(*ctx, "cpu_id")) { + lttng_remove_context_field(ctx, field); + return -EEXIST; + } + field->event_field.name = "cpu_id"; + field->event_field.type.atype = atype_integer; + field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT; + field->event_field.type.u.basic.integer.alignment = lttng_alignof(int) * CHAR_BIT; + field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(int); + field->event_field.type.u.basic.integer.reverse_byte_order = 0; + field->event_field.type.u.basic.integer.base = 10; + field->event_field.type.u.basic.integer.encoding = lttng_encode_none; + field->get_size = cpu_id_get_size; + field->record = cpu_id_record; + field->get_value = cpu_id_get_value; + lttng_context_update(*ctx); + return 0; +} diff --git a/liblttng-ust/lttng-context.c b/liblttng-ust/lttng-context.c index 6cab7dc1..199ec5d5 100644 --- a/liblttng-ust/lttng-context.c +++ b/liblttng-ust/lttng-context.c @@ -236,6 +236,10 @@ void lttng_context_init(void) if (ret) { WARN("Cannot add context lttng_add_procname_to_ctx"); } + ret = lttng_add_cpu_id_to_ctx(<tng_static_ctx); + if (ret) { + WARN("Cannot add context lttng_add_cpu_id_to_ctx"); + } } void lttng_context_exit(void) diff --git a/liblttng-ust/lttng-events.c b/liblttng-ust/lttng-events.c index 897b7f25..25b49625 100644 --- a/liblttng-ust/lttng-events.c +++ b/liblttng-ust/lttng-events.c @@ -817,6 +817,8 @@ int lttng_attach_context(struct lttng_ust_context *context_param, return lttng_add_procname_to_ctx(ctx); case LTTNG_UST_CONTEXT_IP: return lttng_add_ip_to_ctx(ctx); + case LTTNG_UST_CONTEXT_CPU_ID: + return lttng_add_cpu_id_to_ctx(ctx); default: return -EINVAL; } -- 2.34.1