Messages in this thread | | | Date | Fri, 23 Jul 2021 00:24:33 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v2 1/2] tracing: Have histogram types be constant when possible |
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On Thu, 22 Jul 2021 10:27:06 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org> > > Instead of kstrdup("const", GFP_KERNEL), have the hist_field type simply > assign the constant hist_field->type = "const"; And when the value passed > to it is a variable, use "kstrdup_const(var, GFP_KERNEL);" which will just > copy the value if the variable is already a constant. This saves on having > to allocate when not needed. > > All frees of the hist_field->type will need to use kfree_const(). >
Thanks! This looks good to me.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
> Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> > --- > kernel/trace/trace_events_hist.c | 32 ++++++++++++++------------------ > 1 file changed, 14 insertions(+), 18 deletions(-) > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c > index 34325f41ebc0..5c9082201bc2 100644 > --- a/kernel/trace/trace_events_hist.c > +++ b/kernel/trace/trace_events_hist.c > @@ -1589,7 +1589,9 @@ static void __destroy_hist_field(struct hist_field *hist_field) > > kfree(hist_field->var.name); > kfree(hist_field->name); > - kfree(hist_field->type); > + > + /* Can likely be a const */ > + kfree_const(hist_field->type); > > kfree(hist_field->system); > kfree(hist_field->event_name); > @@ -1646,9 +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; > } > > @@ -1662,7 +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; > @@ -1671,18 +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; > } > > @@ -1695,7 +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; > > @@ -1708,7 +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; > > @@ -1794,7 +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; > @@ -2163,7 +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; > @@ -2289,7 +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; > @@ -2677,10 +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_const(var->type); > kfree(var->var.name); > - kfree(var->type); > kfree(var); > var = ERR_PTR(-ENOMEM); > } > -- > 2.30.2
-- Masami Hiramatsu <mhiramat@kernel.org>
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