On 07/08/13 21:47, Vince Weaver wrote: > > Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx> Thanks. Applied! Cheers, Michael > diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 > index 504e801..1fc4e27 100644 > --- a/man2/perf_event_open.2 > +++ b/man2/perf_event_open.2 > @@ -654,8 +654,13 @@ Records additional data, if applicable. > Usually returned by tracepoint events. > .TP > .BR PERF_SAMPLE_BRANCH_STACK " (Since Linux 3.4)" > -Records the branch stack. > -See branch_sample_type. > +This provides a record of recent branches, as provided > +by CPU branch sampling hardware (such as Intel Last Branch Record). > +Not all hardware supports this feature. > + > +See the > +.I branch_sample_type > +field for how to filter which branches are reported. > .TP > .BR PERF_SAMPLE_REGS_USER " (Since Linux 3.7)" > Records the current user-level CPU register state > @@ -960,8 +965,17 @@ is a further extension of the > field. > .TP > .IR "branch_sample_type" " (Since Linux 3.4)" > -This is used with the CPUs hardware branch sampling, if available. > -It can have one of the following values: > +If > +.B PERF_SAMPLE_BRANCH_STACK > +is enabled, then this specifies what branches to include > +in the branch record. > +If the user does not set privilege level explicitly, the kernel > +will use the event's privilege level. > +Event and branch privilege levels do not have to match. > +The value is formed by ORing together zero or more of the following values, > +although > +.B PERF_SAMPLE_BRANCH_ANY > +covers all branch types. > .RS > .TP > .B PERF_SAMPLE_BRANCH_USER > @@ -1545,9 +1559,31 @@ is enabled, then a 64-bit value indicating > the number of records is included, followed by > .I bnr > .I perf_branch_entry > -structures. > -These structures have from, to, and flags values indicating > -the from and to addresses from the branches on the callstack. > +structures which each include the fields: > +.RS > +.TP > +.I from > +indicating the source instruction (may not be a branch) > +.TP > +.I to > +the branch target > +.TP > +.I mispred > +the branch target was mispredicted > +.TP > +.I predicted > +the branch target was predicted. > +.RE > +The entries are from most to least recent, so the first entry > +has the most recent branch. > + > +Support for > +.I mispred > +and > +.I predicted > +is optional; if not supported both > +values will be 0. > + > .TP > .IR abi ", " regs[weight(mask)] > If > -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
