On 09/12/2013 01:37 AM, Stephen Warren wrote: > On 09/11/2013 01:46 PM, Srivatsa S. Bhat wrote: >> On 09/12/2013 12:33 AM, Stephen Warren wrote: >>> On 09/11/2013 12:42 PM, Srivatsa S. Bhat wrote: >>> ... >>>> OK, I took a second look at the code, and I suspect that applying the >>>> second patch might help. So can you try by applying both the patches >>>> please[1][2]? >>>> >>> ... >>>> [1]. http://marc.info/?l=linux-kernel&m=137889516210816&w=2 >>>> [2]. http://marc.info/?l=linux-kernel&m=137889800511940&w=2 >>> >>> Yes, with both of those patches applies, the problem is solved:-) >>> >>> I was going to test the second patch originally, but it sounded like it >>> was more of a cleanup rather than a fix for my issue, so I didn't bother >>> when I found the problem wasn't solved by patch 1. Sorry! >>> >> >> Well, honestly, even I had intended the second patch as a cleanup and >> hadn't asked you to test it ;-) Only when you reported that the first patch >> failed to solve your problem, I realized that the second patch was >> important too! :-) Thanks for testing! >> >>> For the record, I'm testing on a 2-CPU system, so I'm not sure whether >>> your explanation applies; it talks about CPUs 2 and 3 whereas I only >>> have CPUs 0 and 1, but perhaps your explanation applies equally to any >>> pair of CPUs? >>> >> >> Yes, it applies to any pair of CPUs, as long as the CPU first taken down >> is not the policy->cpu. In your case, it applies like this: >> IIUC, CPU0 is the boot cpu, and hence it wont be taken offline using hotplug. >> So only CPU 1 is taken offline during suspend. And if it is not the >> policy->cpu, >> then it hits the very same bug that I described with the analogy of CPUs 2 >> and 3. >> >>> For the record, here's the information you requested in the other email: >>> >>> # cat /sys/devices/system/cpu/cpu*/cpufreq/related_cpus >>> 0 1 >>> 0 1 >> >> Thanks! It would have been more useful to somehow know which was the >> policy->cpu. But looking at the problem, certainly CPU0 was the policy->cpu >> in your case. > > Yes, I believe CPU0 since, > >> # ls -l /sys/devices/system/cpu/cpu1/cpufreq >> lrwxrwxrwx 1 root root 0 Jan 1 00:01 /sys/devices/system/cpu/cpu1/cpufreq >> -> ../cpu0/cpufreq > > and cpu0/cpufreq/ has all the files in it. > > ...
Ah, nice! >> So can you see if patch 1 + this above fix solves your problem as well? >> Then we can retain the original patch 2 as a cleanup, after these 2 patches. >> This organization also makes the code look better and understandable. > > Yes, both patch 1+3 and 1+3+2 work fine. > Cool! Thanks a lot for all your testing efforts Stephen! :-) Regards, Srivatsa S. Bhat -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
