On 09/23/2016 06:24 PM, Santosh Shilimkar wrote: > On 9/23/2016 7:26 AM, Tony Lindgren wrote: >> * Peter Ujfalusi <peter.ujfalusi@xxxxxx> [160923 00:21]: >>> On 09/22/16 21:07, Tony Lindgren wrote: > > [...] > >>> On which linux-next version you are seeing this? >> >> This was with next-20160922. But testing it again this is just another >> regression caused by "softirq: fix tasklet_kill() and its users", so adding >> Santosh to Cc. >> >> So no need to revert $subject patch. >> > So your driver also looks like fiddling with tasklet core structures if > you got impacted because of the core change. How is that? None of the drivers in the twl6040 stack uses tasklets explicitly. The core uses regmap_irq and the drivers use threaded irq when they need interrupt handling, but no tasklet, no fiddling with internals. -- Péter > After the merge window > am going to take stab at bad users of tasklet but below is > quick snap shot conversation I had with Thomas and Andrew... > > ------------------------------------------------------------------ > B1;2802;0cOn Wed, 21 Sep 2016, Santosh Shilimkar wrote: >> I requested you to include this patch but now am not sure anymore. >> Looks like there are almost 30 more users which are directly >> tweaking 'tasklet_struct' fields and calling other APIs. Hunting them >> and fixing them probably would be an exercise and also those changes >> needs those changed drivers to be tested. >> >> What do you suggest ? At least this patch needs to be dropped as of now >> till we can have complete coverage for those bad users. > > Yes, it needs to be dropped. Stephen, can you please revert it from next? > > How to fix this: The only way is to review all tasklet usage sites for > creative abuse and then fix them one by one. This needs to be done anyway > because those are ticking timebombs even without changes in the core > code. I looked at one of the offenders and it's broken today, it's just > protected by the extremly low probablity to hit the wreckage case. > > What you can do to coerce the developers/maintainers of offending code into > looking at the mess they created/merged is to implement accessors for the > tasklet struct fields and replace the open coded fiddling with them. > > Once that is done, rename the struct fields to something which is absurd > enough to type. But don't worry, you will find people doing that. I > catched a few brainwrecks who actually used: > > irqdesc->core_internal_state__do_not_mess_with_it > > in their code. > > Now after having everything converted to accessors, you can add sanity > checks into the accessors and emit WARN_ONCE() when they are used in the > wrong context. That'll make them look and explain why they think that > fiddling in the internals is a good idea. > > Thanks, > > tglx > ------------------------------------------------------------------ > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
