Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932306Ab2BIWYx (ORCPT ); Thu, 9 Feb 2012 17:24:53 -0500 Received: from mail-ww0-f44.google.com ([74.125.82.44]:53325 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932262Ab2BIWXG (ORCPT ); Thu, 9 Feb 2012 17:23:06 -0500 MIME-Version: 1.0 From: Stephane Eranian To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, mingo@elte.hu, acme@redhat.com, robert.richter@amd.com, ming.m.lin@intel.com, andi@firstfloor.org, asharma@fb.com, ravitillo@lbl.gov, vweaver1@eecs.utk.edu, khandual@linux.vnet.ibm.com, dsahern@gmail.com Subject: [PATCH v6 12/18] perf: add support for sampling taken branch to perf record Date: Thu, 9 Feb 2012 23:21:02 +0100 Message-Id: <1328826068-11713-13-git-send-email-eranian@google.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1328826068-11713-1-git-send-email-eranian@google.com> References: <1328826068-11713-1-git-send-email-eranian@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6364 Lines: 196 From: Roberto Agostino Vitillo This patch adds a new option to enable taken branch stack sampling, i.e., leverage the PERF_SAMPLE_BRANCH_STACK feature of perf_events. There is a new option to active this mode: -b. It is possible to pass a set of filters to select the type of branches to sample. The following filters are available: - any : any type of branches - any_call : any function call or system call - any_ret : any function return or system call return - any_ind : any indirect branch - u: only when the branch target is at the user level - k: only when the branch target is in the kernel - hv: only when the branch target is in the hypervisor Filters can be combined by passing a comma separated list to the option: $ perf record -b any_call,u -e cycles:u branchy Signed-off-by: Roberto Agostino Vitillo Signed-off-by: Stephane Eranian --- tools/perf/Documentation/perf-record.txt | 25 ++++++++++ tools/perf/builtin-record.c | 74 ++++++++++++++++++++++++++++++ tools/perf/perf.h | 1 + tools/perf/util/evsel.c | 4 ++ 4 files changed, 104 insertions(+), 0 deletions(-) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index ff9a66e..288d429 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -152,6 +152,31 @@ an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must ha corresponding events, i.e., they always refer to events defined earlier on the command line. +-b:: +--branch-stack:: +Enable taken branch stack sampling. Each sample captures a series of consecutive +taken branches. The number of branches captured with each sample depends on the +underlying hardware, the type of branches of interest, and the executed code. +It is possible to select the types of branches captured by enabling filters. The +following filters are defined: + + - any : any type of branches + - any_call: any function call or system call + - any_ret: any function return or system call return + - any_ind: any indirect branch + - u: only when the branch target is at the user level + - k: only when the branch target is in the kernel + - hv: only when the target is at the hypervisor level + ++ +At least one of any, any_call, any_ret, any_ind must be provided. The privilege levels may +be ommitted, in which case, the privilege levels of the associated event are applied to the +branch filter. Both kernel (k) and hypervisor (hv) privilege levels are subject to +permissions. When sampling on multiple events, branch stack sampling is enabled for all +the sampling events. The sampled branch type is the same for all events. +Note that taken branch sampling may not be available on all processors. +The various filters must be specified as a comma separated list: -b any_ret,u,k + SEE ALSO -------- linkperf:perf-stat[1], linkperf:perf-list[1] diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index f8d9a54..9f07418 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -627,6 +627,77 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv) return err; } +#define BRANCH_OPT(n, m) \ + { .name = n, .mode = (m) } + +#define BRANCH_END { .name = NULL } + +struct branch_mode { + const char *name; + int mode; +}; + +static const struct branch_mode branch_modes[] = { + BRANCH_OPT("u", PERF_SAMPLE_BRANCH_USER), + BRANCH_OPT("k", PERF_SAMPLE_BRANCH_KERNEL), + BRANCH_OPT("hv", PERF_SAMPLE_BRANCH_HV), + BRANCH_OPT("any", PERF_SAMPLE_BRANCH_ANY), + BRANCH_OPT("any_call", PERF_SAMPLE_BRANCH_ANY_CALL), + BRANCH_OPT("any_ret", PERF_SAMPLE_BRANCH_ANY_RETURN), + BRANCH_OPT("ind_call", PERF_SAMPLE_BRANCH_IND_CALL), + BRANCH_END +}; + +static int +parse_branch_stack(const struct option *opt, const char *str, int unset __used) +{ +#define ONLY_PLM \ + (PERF_SAMPLE_BRANCH_USER |\ + PERF_SAMPLE_BRANCH_KERNEL |\ + PERF_SAMPLE_BRANCH_HV) + + uint64_t *mode = (uint64_t *)opt->value; + const struct branch_mode *br; + char *s, *os, *p; + int ret = -1; + + *mode = 0; + + /* because str is read-only */ + s = os = strdup(str); + if (!s) + return -1; + + for (;;) { + p = strchr(s, ','); + if (p) + *p = '\0'; + + for (br = branch_modes; br->name; br++) { + if (!strcasecmp(s, br->name)) + break; + } + if (!br->name) + goto error; + + *mode |= br->mode; + + if (!p) + break; + + s = p + 1; + } + ret = 0; + + if ((*mode & ~ONLY_PLM) == 0) { + error("need at least one branch type with -b\n"); + ret = -1; + } +error: + free(os); + return ret; +} + static const char * const record_usage[] = { "perf record [] []", "perf record [] -- []", @@ -719,6 +790,9 @@ const struct option record_options[] = { "monitor event in cgroup name only", parse_cgroups), OPT_STRING('u', "uid", &record.uid_str, "user", "user to profile"), + OPT_CALLBACK('b', "branch-stack", &record.opts.branch_stack, + "branch mode mask", "branch stack sampling modes", + parse_branch_stack), OPT_END() }; diff --git a/tools/perf/perf.h b/tools/perf/perf.h index 8b4d25d..7f8fbab 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -222,6 +222,7 @@ struct perf_record_opts { unsigned int freq; unsigned int mmap_pages; unsigned int user_freq; + int branch_stack; u64 default_interval; u64 user_interval; const char *cpu_list; diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index f310aa5..9f66df6 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -126,6 +126,10 @@ void perf_evsel__config(struct perf_evsel *evsel, struct perf_record_opts *opts) attr->watermark = 0; attr->wakeup_events = 1; } + if (opts->branch_stack) { + attr->sample_type |= PERF_SAMPLE_BRANCH_STACK; + attr->branch_sample_type = opts->branch_stack; + } attr->mmap = track; attr->comm = track; -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/