From 53651b28cfb637ef604abc189d877948d1af39bb Mon Sep 17 00:00:00 2001 From: yuzhoujian Date: Thu, 30 May 2019 14:29:22 +0100 Subject: [PATCH] perf record: Add support to collect callchains from kernel or user space only One can just record callchains in the kernel or user space with this new options. We can use it together with "--all-kernel" options. This two options is used just like print_stack(sys) or print_ustack(usr) for systemtap. Shown below is the usage of this new option combined with "--all-kernel" options: 1. Configure all used events to run in kernel space and just collect kernel callchains. $ perf record -a -g --all-kernel --kernel-callchains 2. Configure all used events to run in kernel space and just collect user callchains. $ perf record -a -g --all-kernel --user-callchains Committer notes: Improved documentation to state that asking for kernel callchains really is asking for excluding user callchains, and vice versa. Further mentioned that using both won't get both, but nothing, as both will be excluded. Signed-off-by: yuzhoujian Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: David Ahern Cc: Milian Wolff Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1559222962-22891-1-git-send-email-ufo19890607@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-record.txt | 11 +++++++++++ tools/perf/builtin-record.c | 4 ++++ tools/perf/perf.h | 2 ++ tools/perf/util/evsel.c | 4 ++++ 4 files changed, 21 insertions(+) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index de26943..15e0fa8 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -490,6 +490,17 @@ Configure all used events to run in kernel space. --all-user:: Configure all used events to run in user space. +--kernel-callchains:: +Collect callchains only from kernel space. I.e. this option sets +perf_event_attr.exclude_callchain_user to 1. + +--user-callchains:: +Collect callchains only from user space. I.e. this option sets +perf_event_attr.exclude_callchain_kernel to 1. + +Don't use both --kernel-callchains and --user-callchains at the same time or no +callchains will be collected. + --timestamp-filename Append timestamp to output file name. diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index e2c3a58..dca5599 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -2191,6 +2191,10 @@ static struct option __record_options[] = { OPT_BOOLEAN_FLAG(0, "all-user", &record.opts.all_user, "Configure all used events to run in user space.", PARSE_OPT_EXCLUSIVE), + OPT_BOOLEAN(0, "kernel-callchains", &record.opts.kernel_callchains, + "collect kernel callchains"), + OPT_BOOLEAN(0, "user-callchains", &record.opts.user_callchains, + "collect user callchains"), OPT_STRING(0, "clang-path", &llvm_param.clang_path, "clang path", "clang binary to use for compiling BPF scriptlets"), OPT_STRING(0, "clang-opt", &llvm_param.clang_opt, "clang options", diff --git a/tools/perf/perf.h b/tools/perf/perf.h index d59dee6..711e009 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -61,6 +61,8 @@ struct record_opts { bool record_switch_events; bool all_kernel; bool all_user; + bool kernel_callchains; + bool user_callchains; bool tail_synthesize; bool overwrite; bool ignore_missing_thread; diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index cc6e7a0..9f3b580 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -680,6 +680,10 @@ static void __perf_evsel__config_callchain(struct perf_evsel *evsel, attr->sample_max_stack = param->max_stack; + if (opts->kernel_callchains) + attr->exclude_callchain_user = 1; + if (opts->user_callchains) + attr->exclude_callchain_kernel = 1; if (param->record_mode == CALLCHAIN_LBR) { if (!opts->branch_stack) { if (attr->exclude_user) { -- 2.7.4