On 3/26/18 9:17 AM, Mathieu Desnoyers wrote:
re: 'added complexity'...
- for (iter = begin; iter < end; iter++)
- fct(*iter, priv);
+ return NULL;
+ for (iter = begin; iter < end; iter++) {
+ ret = fct(*iter, priv);
+ if (ret)
+ return ret;
+ }
+ return NULL;
where do you see 'added complexity' ?
Isn't the above diff self-explanatory that for_each_tracepoint_range()
can be used not only to iterate over all tracepoints
(just do 'return NULL') from callback _and_ to find one particular
tracepoint as patch 7 does ?
I am not arguing about your proposed implementation. I am arguing about
the lack of justification behind this change. Why is this change needed ?
What is it allowing you to do that cannot be done using the private data
pointer ?
commit log of patch 6 states:
"for_each_tracepoint_range() api has no users inside the kernel.
Make it more useful with ability to stop for_each() loop depending
via callback return value.
In such form it's used in subsequent patch."
and in patch 7:
+static void *__find_tp(struct tracepoint *tp, void *priv)
+{
+ char *name = priv;
+
+ if (!strcmp(tp->name, name))
+ return tp;
+ return NULL;
+}
...
+ struct tracepoint *tp;
...
+ tp = for_each_kernel_tracepoint(__find_tp, tp_name);
+ if (!tp)
+ return -ENOENT;
still not obvious?
