Messages in this thread | | | Date | Fri, 23 Jul 2021 00:05:55 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v2] tracing: Allow execnames to be passed as args for synthetic events |
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On Thu, 22 Jul 2021 09:46:38 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> On Thu, 22 Jul 2021 22:29:24 +0900 > Masami Hiramatsu <mhiramat@kernel.org> wrote: > > > This looks an interesting improvement. If we can do this, can we also filter > > the event by 'comm' (or execname)? > > We would be able to filter on the synthetic event, just like any other > event with a comm (or other string) But I don't think we can filter > before (that is, in the histogram code). > > > > > > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> > > > --- > > > Changes since v1: > > > - Hit a bug on freeing the histogram, found that I used "char[]" for the > > > type, and it expects to be freed. Freed the old "type" and still use > > > "char[]" but have the normal freeing use kfree_const() on type. > > > > > > BTW, if we can use this technic on the hist_field->type, we can cleanup > > other type = strdup("<any const type>", GFP_KERNEL) with type = "<any const type>" ? > > > > Anyway, that will be done in another patch (I think that should be done first, > > then we can avoid an odd kfree() in update_var_execname().) > > You mean like this? It was done after the patch, but I can move it first.
Yes, this looks good to me.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Thank you,
> > -- Steve > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c > index bb1956efd5ef..6b9e4fb70bc1 100644 > --- a/kernel/trace/trace_events_hist.c > +++ b/kernel/trace/trace_events_hist.c > @@ -1590,7 +1590,7 @@ static void __destroy_hist_field(struct hist_field *hist_field) > kfree(hist_field->var.name); > kfree(hist_field->name); > > - /* execname vars use a constant type */ > + /* Can likely be a const */ > kfree_const(hist_field->type); > > kfree(hist_field->system); > @@ -1648,9 +1648,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > if (flags & HIST_FIELD_FL_HITCOUNT) { > hist_field->fn = hist_field_counter; > hist_field->size = sizeof(u64); > - hist_field->type = kstrdup("u64", GFP_KERNEL); > - if (!hist_field->type) > - goto free; > + hist_field->type = "u64"; > goto out; > } > > @@ -1664,7 +1662,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > hist_field->fn = hist_field_log2; > hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL); > hist_field->size = hist_field->operands[0]->size; > - hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL); > + hist_field->type = kstrdup_const(hist_field->operands[0]->type, GFP_KERNEL); > if (!hist_field->type) > goto free; > goto out; > @@ -1673,18 +1671,14 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > if (flags & HIST_FIELD_FL_TIMESTAMP) { > hist_field->fn = hist_field_timestamp; > hist_field->size = sizeof(u64); > - hist_field->type = kstrdup("u64", GFP_KERNEL); > - if (!hist_field->type) > - goto free; > + hist_field->type = "u64"; > goto out; > } > > if (flags & HIST_FIELD_FL_CPU) { > hist_field->fn = hist_field_cpu; > hist_field->size = sizeof(int); > - hist_field->type = kstrdup("unsigned int", GFP_KERNEL); > - if (!hist_field->type) > - goto free; > + hist_field->type = "unsigned int"; > goto out; > } > > @@ -1697,7 +1691,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > flags |= HIST_FIELD_FL_STRING; > > hist_field->size = MAX_FILTER_STR_VAL; > - hist_field->type = kstrdup(field->type, GFP_KERNEL); > + hist_field->type = kstrdup_const(field->type, GFP_KERNEL); > if (!hist_field->type) > goto free; > > @@ -1710,7 +1704,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > } else { > hist_field->size = field->size; > hist_field->is_signed = field->is_signed; > - hist_field->type = kstrdup(field->type, GFP_KERNEL); > + hist_field->type = kstrdup_const(field->type, GFP_KERNEL); > if (!hist_field->type) > goto free; > > @@ -1796,7 +1790,7 @@ static int init_var_ref(struct hist_field *ref_field, > } > } > > - ref_field->type = kstrdup(var_field->type, GFP_KERNEL); > + ref_field->type = kstrdup_const(var_field->type, GFP_KERNEL); > if (!ref_field->type) { > err = -ENOMEM; > goto free; > @@ -2165,7 +2159,7 @@ static struct hist_field *parse_unary(struct hist_trigger_data *hist_data, > expr->operands[0] = operand1; > expr->operator = FIELD_OP_UNARY_MINUS; > expr->name = expr_str(expr, 0); > - expr->type = kstrdup(operand1->type, GFP_KERNEL); > + expr->type = kstrdup_const(operand1->type, GFP_KERNEL); > if (!expr->type) { > ret = -ENOMEM; > goto free; > @@ -2291,7 +2285,7 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, > expr->operands[1] = operand2; > expr->operator = field_op; > expr->name = expr_str(expr, 0); > - expr->type = kstrdup(operand1->type, GFP_KERNEL); > + expr->type = kstrdup_const(operand1->type, GFP_KERNEL); > if (!expr->type) { > ret = -ENOMEM; > goto free; > @@ -2679,10 +2673,10 @@ static struct hist_field *create_var(struct hist_trigger_data *hist_data, > var->var.hist_data = var->hist_data = hist_data; > var->size = size; > var->var.name = kstrdup(name, GFP_KERNEL); > - var->type = kstrdup(type, GFP_KERNEL); > + var->type = kstrdup_const(type, GFP_KERNEL); > if (!var->var.name || !var->type) { > kfree(var->var.name); > - kfree(var->type); > + kfree_const(var->type); > kfree(var); > var = ERR_PTR(-ENOMEM); > }
-- Masami Hiramatsu <mhiramat@kernel.org>
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