lkml.org 
[lkml]   [2015]   [Feb]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[tip:perf/core] perf/x86/intel: Allocate space for storing LBR stack
    Commit-ID:  e18bf526422769611e7248135e36a4cea0e4e38d
    Gitweb: http://git.kernel.org/tip/e18bf526422769611e7248135e36a4cea0e4e38d
    Author: Yan, Zheng <zheng.z.yan@intel.com>
    AuthorDate: Tue, 4 Nov 2014 21:56:03 -0500
    Committer: Ingo Molnar <mingo@kernel.org>
    CommitDate: Wed, 18 Feb 2015 17:16:08 +0100

    perf/x86/intel: Allocate space for storing LBR stack

    When the LBR call stack is enabled, it is necessary to save/restore
    the LBR stack on context switch. We can use pmu specific data to
    store LBR stack when task is scheduled out. This patch adds code
    that allocates the pmu specific data.

    Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
    Signed-off-by: Kan Liang <kan.liang@intel.com>
    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Reviewed-by: Stephane Eranian <eranian@google.com>
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Vince Weaver <vincent.weaver@maine.edu>
    Cc: jolsa@redhat.com
    Link: http://lkml.kernel.org/r/1415156173-10035-8-git-send-email-kan.liang@intel.com
    Signed-off-by: Ingo Molnar <mingo@kernel.org>
    ---
    arch/x86/kernel/cpu/perf_event.c | 4 ++++
    arch/x86/kernel/cpu/perf_event.h | 7 +++++++
    2 files changed, 11 insertions(+)

    diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
    index 6b1fd26..8ffd71e 100644
    --- a/arch/x86/kernel/cpu/perf_event.c
    +++ b/arch/x86/kernel/cpu/perf_event.c
    @@ -432,6 +432,9 @@ int x86_pmu_hw_config(struct perf_event *event)
    }
    }

    + if (event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK)
    + event->attach_state |= PERF_ATTACH_TASK_DATA;
    +
    /*
    * Generate PMC IRQs:
    * (keep 'enabled' bit clear for now)
    @@ -1950,6 +1953,7 @@ static struct pmu pmu = {

    .event_idx = x86_pmu_event_idx,
    .sched_task = x86_pmu_sched_task,
    + .task_ctx_size = sizeof(struct x86_perf_task_context),
    };

    void arch_perf_update_userpage(struct perf_event *event,
    diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
    index c9a62c5..69c26b3 100644
    --- a/arch/x86/kernel/cpu/perf_event.h
    +++ b/arch/x86/kernel/cpu/perf_event.h
    @@ -516,6 +516,13 @@ struct x86_pmu {
    struct perf_guest_switch_msr *(*guest_get_msrs)(int *nr);
    };

    +struct x86_perf_task_context {
    + u64 lbr_from[MAX_LBR_ENTRIES];
    + u64 lbr_to[MAX_LBR_ENTRIES];
    + int lbr_callstack_users;
    + int lbr_stack_state;
    +};
    +
    enum {
    PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT = PERF_SAMPLE_BRANCH_MAX_SHIFT,
    PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE,

    \
     
     \ /
      Last update: 2015-02-18 18:41    [W:4.197 / U:0.324 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site