Re: [PATCH 1/2] mm, printk: introduce new format string for flags

Steven Rostedt
2015-12-10T04:03:27Z

On Fri, Dec 04, 2015 at 03:15:45PM +0100, Vlastimil Babka wrote:
> On 12/03/2015 07:38 PM, yalin wang wrote:
> >that’s all, see cpumask_pr_args(masks) macro,
> >it also use macro and %*pb to print cpu mask .
> >i think this method is not very complex to use .
>
> Well, one also has to write the appropriate translation tables.
>
> >search source code ,
> >there is lots of printk to print flag into hex number :
> >$ grep -n -r 'printk.*flag.*%x’ .
> >it will be great if this flag string print is generic.
>
> I think it can always be done later, this is an internal API. For now we
> just have 3 quite generic flags, so let's not over-engineer things right
> now.
>

As long as it is never used in the TP_printk() part of a tracepoint. As soon
as it is, trace-cmd and perf will update parse-events to handle that
parameter, and as soon as that is done, it becomes a userspace ABI.

Just be warned.

-- Steve