lkml.org 
[lkml]   [2010]   [Jan]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[tip:perf/core] perf_event: x86: Optimize constraint weight computation
    Commit-ID:  272d30be622c9c6cbd514b1211ff359292001baa
    Gitweb: http://git.kernel.org/tip/272d30be622c9c6cbd514b1211ff359292001baa
    Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
    AuthorDate: Fri, 22 Jan 2010 16:32:17 +0100
    Committer: Ingo Molnar <mingo@elte.hu>
    CommitDate: Fri, 29 Jan 2010 09:01:41 +0100

    perf_event: x86: Optimize constraint weight computation

    Add a weight member to the constraint structure and avoid recomputing the
    weight at runtime.

    Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Stephane Eranian <eranian@google.com>
    LKML-Reference: <20100122155535.963944926@chello.nl>
    Signed-off-by: Ingo Molnar <mingo@elte.hu>
    ---
    arch/x86/kernel/cpu/perf_event.c | 9 +++++----
    1 files changed, 5 insertions(+), 4 deletions(-)

    diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
    index 092ad56..2c22ce4 100644
    --- a/arch/x86/kernel/cpu/perf_event.c
    +++ b/arch/x86/kernel/cpu/perf_event.c
    @@ -23,6 +23,7 @@
    #include <linux/uaccess.h>
    #include <linux/highmem.h>
    #include <linux/cpu.h>
    +#include <linux/bitops.h>

    #include <asm/apic.h>
    #include <asm/stacktrace.h>
    @@ -76,6 +77,7 @@ struct event_constraint {
    };
    int code;
    int cmask;
    + int weight;
    };

    struct cpu_hw_events {
    @@ -95,6 +97,7 @@ struct cpu_hw_events {
    { .idxmsk64[0] = (n) }, \
    .code = (c), \
    .cmask = (m), \
    + .weight = HWEIGHT64((u64)(n)), \
    }

    #define INTEL_EVENT_CONSTRAINT(c, n) \
    @@ -1242,8 +1245,7 @@ static inline int is_x86_event(struct perf_event *event)

    static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
    {
    - int i, j , w, num;
    - int weight, wmax;
    + int i, j, w, num, wmax;
    struct event_constraint *c, *constraints[X86_PMC_IDX_MAX];
    unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
    struct hw_perf_event *hwc;
    @@ -1320,8 +1322,7 @@ static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
    c = constraints[i];
    hwc = &cpuc->event_list[i]->hw;

    - weight = bitmap_weight(c->idxmsk, X86_PMC_IDX_MAX);
    - if (weight != w)
    + if (c->weight != w)
    continue;

    for_each_bit(j, c->idxmsk, X86_PMC_IDX_MAX) {

    \
     
     \ /
      Last update: 2010-01-29 10:33    [W:0.039 / U:0.200 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site