CCing the sparc maintainer. Also CCing the regression list, as it should be in the loop for regressions: https://docs.kernel.org/admin-guide/reporting-regressions.html The the mail address of the culprit's author bounces. There is another Atish Patra still active; does anyone known if those two are the same person? Anyway, that's it from my side. Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr If I did something stupid, please tell me, as explained on that page. On 20.01.23 04:15, Nick Bowler wrote: > Hi, > > I'm resending this report CC'd to linux-kernel as there was no response > on the sparclinux list. > > I tried 6.2-rc4 and there is no change in behaviour. Reverting the > indicated commit still works to fix the problem. > > On 2022-07-12, Nick Bowler <nbowler@xxxxxxxxxx> wrote: >> When using newer kernels on my Ultra 60 with dual 450MHz UltraSPARC-II >> CPUs, I noticed that only CPU 0 comes up, while older kernels (including >> 4.7) are working fine with both CPUs. >> >> I bisected the failure to this commit: >> >> 9b2f753ec23710aa32c0d837d2499db92fe9115b is the first bad commit >> commit 9b2f753ec23710aa32c0d837d2499db92fe9115b >> Author: Atish Patra <atish.patra@xxxxxxxxxx> >> Date: Thu Sep 15 14:54:40 2016 -0600 >> >> sparc64: Fix cpu_possible_mask if nr_cpus is set >> >> This is a small change that reverts very easily on top of 5.18: there is >> just one trivial conflict. Once reverted, both CPUs work again. >> >> Maybe this is related to the fact that the CPUs on this system are >> numbered CPU0 and CPU2 (there is no CPU1)? >> >> Here is /proc/cpuinfo on a working kernel: >> >> % cat /proc/cpuinfo >> cpu : TI UltraSparc II (BlackBird) >> fpu : UltraSparc II integrated FPU >> pmu : ultra12 >> prom : OBP 3.23.1 1999/07/16 12:08 >> type : sun4u >> ncpus probed : 2 >> ncpus active : 2 >> D$ parity tl1 : 0 >> I$ parity tl1 : 0 >> cpucaps : flush,stbar,swap,muldiv,v9,mul32,div32,v8plus,vis >> Cpu0ClkTck : 000000001ad31b4f >> Cpu2ClkTck : 000000001ad31b4f >> MMU Type : Spitfire >> MMU PGSZs : 8K,64K,512K,4MB >> State: >> CPU0: online >> CPU2: online >> >> And on a broken kernel: >> >> % cat /proc/cpuinfo >> cpu : TI UltraSparc II (BlackBird) >> fpu : UltraSparc II integrated FPU >> pmu : ultra12 >> prom : OBP 3.23.1 1999/07/16 12:08 >> type : sun4u >> ncpus probed : 2 >> ncpus active : 1 >> D$ parity tl1 : 0 >> I$ parity tl1 : 0 >> cpucaps : flush,stbar,swap,muldiv,v9,mul32,div32,v8plus,vis >> Cpu0ClkTck : 000000001ad31861 >> MMU Type : Spitfire >> MMU PGSZs : 8K,64K,512K,4MB >> State: >> CPU0: online >> >> Let me know if you need any more info. >> >> Thanks, >> Nick >
