On Wed, Jul 26, 2023 at 08:16:16PM +0800, Ze Gao wrote: > Internal representations of task state are likely to be changed or > ordered, and reporting them to userspace without exporting them as > part of API is not a good choice, which can easily break a userspace > observability tool as kernel evolves. For example, perf suffers from > this and still reports wrong states by this patch. > > OTOH, some masqueraded state like TASK_REPORT_IDLE and TASK_REPORT_MAX > are also reported inadvertently, which confuses things even more. > > So add a new variable in company with the old raw value to report task > state in symbolic char, which is self-explaining and no further > translation is needed, and also report priorities in 'short' to save > some buffer space. Of course this does not break any userspace tool. > > Note for PREEMPT_ACTIVE, we introduce 'p' to report it and use the old > conventions for the rest. So I really dont much like this. This looses the ability to see the actual wait state flags, there could be multiple. Eg, things like TASK_FREEZEABLE gets lost completely. And this is on top of my reluctance to touch any of this at all, for fear of further regressions.
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