On 11/15/2017 11:37 AM, Rafael J. Wysocki wrote: > On Wed, Nov 15, 2017 at 7:14 PM, Sudeep Holla <sudeep.holla@xxxxxxx> wrote: >> >> On 15/11/17 15:33, Timur Tabi wrote: >>> On Wed, Nov 8, 2017 at 8:18 AM, Sudeep Holla <sudeep.holla@xxxxxxx> wrote: >>>> I still prefer this as debugfs and not as sysfs ABI. We already have >>>> issues with multiple interfaces for the same thing. E.g. cpufreq on x86. >>>> I don't want this to end up in the same way after few years. CPUIdle >>>> sysfs should be only sysfs ABI for these, adding an alternative is >>>> inviting troubles for future especially if some user-space starts using >>>> it and we will be stuck with that. Moreover with more h/w controlled >>>> idle we may not provide accurate data sooner. >>>> >>>> Sorry for the noise, I will shup up now ;). Since this may be last >>>> chance to make some noise, I am trying it. I completely understand that >>>> this is just my opinion and am fine if others thinks it's good to make >>>> this sysfs ABI. >>> Unfortunately, I think Prashanth really needs a specific requirement >>> rather than opinions. >> I completely understand that. So for I haven't got a solid reason as >> why debugfs is not sufficient? If it becomes so popular in future, we >> can discuss and then make it sysfs ABI with more thoughts/discussions. > Well, the recent discussions regarding tracepoints indicate that the > ABI rule is not really about where the stuff is located in the > directory structure. :-) > > The main question to me is whether or not the information exposed is > more suitable for debugfs or for sysfs, considering all of the > limitations (like one value per file rule in sysfs etc). > > Of course, debugfs means that the users of, say, Android will not be > able to access this information, but should that really influence > decisions at the technical level? > >>> This patch has been languishing for over a month, and we still have >>> no idea whether it will make 4.15 or if Prashanth is *required* to >>> make any more changes. >>> >> It's sysfs ABI which we need to support for very long time(not in months >> but in years), so waiting/discussing for couple of months is much safer >> than spending more time to keep it the sysfs ABI unbroken. > In either case we need to be sure that the information is exposed the > way everybody (who cares) likes and there won't be future attempts to > tweak it to some needs that were not expressed at the outset. > > IOW, I'd like more people to look at this and let me know what they think. > >> Also I assume(was explicitly mentioned IIRC) that it's purely used >> for debug and tuning purposes and hence I see *no need* to be part of >> *sysfs ABI*. Let me know if the circumstances have changed. > And that is a good argument for putting it into debugs. Thanks Rafael and Sudeep! I will take a look at moving this to debugfs. -- Thanks, Prashanth -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
