On 6/10/2021 4:23 AM, Viresh Kumar wrote: > Hi Qian, > > It would be helpful if you can test this patchset and confirm if the races you > mentioned went away or not and that the FIE code works as we wanted it to. > > I don't have a real setup and so it won't be easy for me to test this out. > > I have already sent a temporary fix for 5.13 and this patchset is targeted for > 5.14 and is based over that. Unfortunately, this series looks like needing more works. [ 487.773586][ T0] CPU17: Booted secondary processor 0x0000000801 [0x503f0002] [ 487.976495][ T670] list_del corruption. next->prev should be ffff009b66e9ec70, but was ffff009b66dfec70 [ 487.987037][ T670] ------------[ cut here ]------------ [ 487.992351][ T670] kernel BUG at lib/list_debug.c:54! [ 487.997810][ T670] Internal error: Oops - BUG: 0 [#1] SMP [ 488.003295][ T670] Modules linked in: cpufreq_userspace xfs loop cppc_cpufreq processor efivarfs ip_tables x_tables ext4 mbcache jbd2 dm_mod igb i2c_algo_bit nvme mlx5_core i2c_core nvme_core firmware_class [ 488.021759][ T670] CPU: 1 PID: 670 Comm: cppc_fie Not tainted 5.13.0-rc5-next-20210611+ #46 [ 488.030190][ T670] Hardware name: MiTAC RAPTOR EV-883832-X3-0001/RAPTOR, BIOS 1.6 06/28/2020 [ 488.038705][ T670] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--) [ 488.045398][ T670] pc : __list_del_entry_valid+0x154/0x158 [ 488.050969][ T670] lr : __list_del_entry_valid+0x154/0x158 [ 488.056534][ T670] sp : ffff8000229afd70 [ 488.060534][ T670] x29: ffff8000229afd70 x28: ffff0008c8f4f340 x27: dfff800000000000 [ 488.068361][ T670] x26: ffff009b66e9ec70 x25: ffff800011c8b4d0 x24: ffff0008d4bfe488 [ 488.076188][ T670] x23: ffff0008c8f4f340 x22: ffff0008c8f4f340 x21: ffff009b6789ec70 [ 488.084015][ T670] x20: ffff0008d4bfe4c8 x19: ffff009b66e9ec70 x18: ffff0008c8f4fd70 [ 488.091842][ T670] x17: 20747562202c3037 x16: 6365396536366239 x15: 0000000000000028 [ 488.099669][ T670] x14: 0000000000000000 x13: 0000000000000001 x12: ffff60136cdd3447 [ 488.107495][ T670] x11: 1fffe0136cdd3446 x10: ffff60136cdd3446 x9 : ffff8000103ee444 [ 488.115322][ T670] x8 : ffff009b66e9a237 x7 : 0000000000000001 x6 : ffff009b66e9a230 [ 488.123149][ T670] x5 : 00009fec9322cbba x4 : ffff60136cdd3447 x3 : 1fffe001191e9e69 [ 488.130975][ T670] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000054 [ 488.138803][ T670] Call trace: [ 488.141935][ T670] __list_del_entry_valid+0x154/0x158 [ 488.147153][ T670] kthread_worker_fn+0x15c/0xda0 [ 488.151939][ T670] kthread+0x3ac/0x460 [ 488.155854][ T670] ret_from_fork+0x10/0x18 [ 488.160120][ T670] Code: 911e8000 aa1303e1 910a0000 941b595b (d4210000) [ 488.166901][ T670] ---[ end trace e637e2d38b2cc087 ]--- [ 488.172206][ T670] Kernel panic - not syncing: Oops - BUG: Fatal exception [ 488.179182][ T670] SMP: stopping secondary CPUs [ 489.209347][ T670] SMP: failed to stop secondary CPUs 0-1,10-11,16-17,31 [ 489.216128][ T][ T670] Memoryn ]--- > > -------------------------8<------------------------- > > The CPPC driver currently stops the frequency invariance related > kthread_work and irq_work from cppc_freq_invariance_exit() which is only > called during driver's removal. > > This is not sufficient as the CPUs can get hot-plugged out while the > driver is in use, the same also happens during system suspend/resume. > > In such a cases we can reach a state where the CPU is removed by the > kernel but its kthread_work or irq_work aren't stopped. > > Fix this by implementing the start_cpu() and stop_cpu() callbacks in the > cpufreq core, which will be called for each CPU's addition/removal. > > A similar call was already available in the cpufreq core, which isn't required > anymore and so its users are migrated to use exit() callback instead. > > This is targeted for v5.14-rc1. > > -- > Viresh > > Viresh Kumar (5): > cpufreq: cppc: Migrate to ->exit() callback instead of ->stop_cpu() > cpufreq: intel_pstate: Migrate to ->exit() callback instead of > ->stop_cpu() > cpufreq: powerenv: Migrate to ->exit() callback instead of > ->stop_cpu() > cpufreq: Add start_cpu() and stop_cpu() callbacks > cpufreq: cppc: Fix suspend/resume specific races with the FIE code > > Documentation/cpu-freq/cpu-drivers.rst | 7 +- > drivers/cpufreq/Kconfig.arm | 1 - > drivers/cpufreq/cppc_cpufreq.c | 163 ++++++++++++++----------- > drivers/cpufreq/cpufreq.c | 11 +- > drivers/cpufreq/intel_pstate.c | 9 +- > drivers/cpufreq/powernv-cpufreq.c | 23 ++-- > include/linux/cpufreq.h | 5 +- > 7 files changed, 119 insertions(+), 100 deletions(-) >
