• Peter Zijlstra's avatar
    perf: Rework the PMU methods · a4eaf7f1
    Peter Zijlstra authored
    Replace pmu::{enable,disable,start,stop,unthrottle} with
    pmu::{add,del,start,stop}, all of which take a flags argument.
    
    The new interface extends the capability to stop a counter while
    keeping it scheduled on the PMU. We replace the throttled state with
    the generic stopped state.
    
    This also allows us to efficiently stop/start counters over certain
    code paths (like IRQ handlers).
    
    It also allows scheduling a counter without it starting, allowing for
    a generic frozen state (useful for rotating stopped counters).
    
    The stopped state is implemented in two different ways, depending on
    how the architecture implemented the throttled state:
    
     1) We disable the counter:
        a) the pmu has per-counter enable bits, we flip that
        b) we program a NOP event, preserving the counter state
    
     2) We store the counter state and ignore all read/overflow events
    Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: paulus <paulus@samba.org>
    Cc: stephane eranian <eranian@googlemail.com>
    Cc: Robert Richter <robert.richter@amd.com>
    Cc: Will Deacon <will.deacon@arm.com>
    Cc: Paul Mundt <lethal@linux-sh.org>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: Cyrill Gorcunov <gorcunov@gmail.com>
    Cc: Lin Ming <ming.m.lin@intel.com>
    Cc: Yanmin <yanmin_zhang@linux.intel.com>
    Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
    Cc: David Miller <davem@davemloft.net>
    Cc: Michael Cree <mcree@orcon.net.nz>
    LKML-Reference: <new-submission>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    a4eaf7f1
ftrace_event.h 7.51 KB