From a5aabdacde9caff54886ae454e0fad2f26929753 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Thu, 8 Mar 2012 23:47:45 +0100 Subject: perf record: Provide default branch stack sampling mode option This patch chanegs the logic of the -b, --branch-stack options of perf record. Based on users' request, the patch provides a default filter mode with the -b (or --branch-any) option. With the option, any type of taken branches is sampled. With -j (or --branch-filter), the user can specify any valid combination of branch types and privilege levels if supported by the underlying hardware. The -b (--branch any) is a shortcut for: --branch-filter any. $ perf record -b foo or: $ perf record --branch-filter any foo For more specific filtering: $ perf record --branch-filter ind_call,u foo Signed-off-by: Stephane Eranian Cc: peterz@infradead.org Cc: acme@redhat.com Cc: asharma@fb.com Cc: ravitillo@lbl.gov Cc: vweaver1@eecs.utk.edu Cc: khandual@linux.vnet.ibm.com Cc: dsahern@gmail.com Link: http://lkml.kernel.org/r/1331246868-19905-2-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar --- tools/perf/Documentation/perf-record.txt | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'tools/perf/Documentation') diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 60bddaf0e5bd..a1386b2fff00 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -153,14 +153,19 @@ corresponding events, i.e., they always refer to events defined earlier on the c line. -b:: ---branch-stack:: +--branch-any:: +Enable taken branch stack sampling. Any type of taken branch may be sampled. +This is a shortcut for --branch-filter any. See --branch-filter for more infos. + +-j:: +--branch-filter:: 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: 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 @@ -169,13 +174,13 @@ following filters are defined: - 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 +The option requires at least one branch type among any, any_call, any_ret, ind_call. +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. +The various filters must be specified as a comma separated list: --branch-filter any_ret,u,k +Note that this feature may not be available on all processors. SEE ALSO -------- -- cgit v1.2.3