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. ... > 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. -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
