lkml.org 
[lkml]   [2016]   [Aug]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    SubjectRe: [PATCH v3 2/3] tracing: Add trace_irqsoff tracepoints
    From
    Date
    On 08/30/2016 04:20 PM, Daniel Wagner wrote:
    > Just setting the size of the type is not enough. The hist_field_*
    > getter function want to know the offset too:

    With this hack here it should work. The COMM generic field is handled via
    the tracing_map_ops. We could do it also there but than we need to
    a condition in the trace_map_ops if it is COMM or CPU.
    This shortcut here avoids it:

    diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
    index 03c0a48..ab8958f 100644
    --- a/kernel/trace/trace_events.c
    +++ b/kernel/trace/trace_events.c
    @@ -152,7 +152,8 @@ EXPORT_SYMBOL_GPL(trace_define_field);

    #define __generic_field(type, item, filter_type) \
    ret = __trace_define_field(&ftrace_generic_fields, #type, \
    - #item, 0, 0, is_signed_type(type), \
    + #item, 0, sizeof(type), \
    + is_signed_type(type), \
    filter_type); \
    if (ret) \
    return ret;
    diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
    index f3a960e..77073b7 100644
    --- a/kernel/trace/trace_events_hist.c
    +++ b/kernel/trace/trace_events_hist.c
    @@ -75,6 +75,11 @@ static u64 hist_field_log2(struct hist_field *hist_field, void *event)
    return (u64) ilog2(roundup_pow_of_two(val));
    }

    +static u64 hist_field_cpu(struct hist_field *hist_field, void *event)
    +{
    + return (u64) smp_processor_id();
    +}
    +
    #define DEFINE_HIST_FIELD_FN(type) \
    static u64 hist_field_##type(struct hist_field *hist_field, void *event)\
    { \
    @@ -119,6 +124,7 @@ enum hist_field_flags {
    HIST_FIELD_FL_SYSCALL = 128,
    HIST_FIELD_FL_STACKTRACE = 256,
    HIST_FIELD_FL_LOG2 = 512,
    + HIST_FIELD_FL_CPU = 1024,
    };

    struct hist_trigger_attrs {
    @@ -371,6 +377,11 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field,
    goto out;
    }

    + if (flags & HIST_FIELD_FL_CPU) {
    + hist_field->fn = hist_field_cpu;
    + goto out;
    + }
    +
    if (WARN_ON_ONCE(!field))
    goto out;

    @@ -556,6 +567,11 @@ static int create_key_field(struct hist_trigger_data *hist_data,
    key_size = MAX_FILTER_STR_VAL;
    else
    key_size = field->size;
    +
    + // strcmp(field_name, "cpu") would also work to figure
    + // out if this is a one of the generic fields.
    + if (field->filter_type == FILTER_CPU)
    + flags |= HIST_FIELD_FL_CPU;
    }

    hist_data->fields[key_idx] = create_hist_field(field, flags);
    \
     
     \ /
      Last update: 2016-09-17 09:58    [W:4.995 / U:0.012 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site