On Wed, 16 Jun 2021 at 08:48, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote: > > Hello, > > Changes since V1: > > - Few of the patches migrating users to ->exit() callback are posted separately. > > - The CPPC patch was completely reverted and so the support for FIE is again > added here from scratch. > > - The start_cpu() and stop_cpu() interface is reworked a little so stop_cpu() is > only ever called for a CPU if start_cpu() was called for it earlier. > > - A new patch to implement RCU locking in arch_topology core to avoid some > races. > > - Some cleanup and very clear/separate paths for FIE in cppc driver now. > > > -------------------------8<------------------------- > > CPPC cpufreq driver is used for ARM servers and this patch series tries to > provide counter-based frequency invariance support for them in the absence for > architecture specific counters (like AMUs). > > This was reverted earlier for the 5.13 kernel after Qian Cai reported kernel > oops during suspend/resume. > > This is based of pm/linux-next + a cleanup patchset: > > https://lore.kernel.org/linux-pm/cover.1623825358.git.viresh.kumar@xxxxxxxxxx/ > > All the patches are pushed here together for people to run. > > https://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm.git/log/?h=cpufreq/cppc > > This is tested on my Hikey platform (without the actual read/write to > performance counters), with this script for over an hour: > > while true; do > for i in `seq 1 7`; > do > echo 0 > /sys/devices/system/cpu/cpu$i/online; > done; > > for i in `seq 1 7`; > do > echo 1 > /sys/devices/system/cpu/cpu$i/online; > done; > done > > > Vincent will be giving this patchset a try on ThunderX2. I tested your branch and got the following while booting: [ 24.454543] zswap: loaded using pool lzo/zbud [ 24.454753] pstore: Using crash dump compression: deflate [ 24.454776] AppArmor: AppArmor sha1 policy hashing enabled [ 24.454784] ima: No TPM chip found, activating TPM-bypass! [ 24.454789] ima: Allocated hash algorithm: sha256 [ 24.454801] ima: No architecture policies found [ 24.455750] pcieport 0000:0f:00.0: Adding to iommu group 0 [ 24.893888] ------------[ cut here ]------------ [ 24.893891] WARNING: CPU: 95 PID: 1442 at drivers/cpufreq/cppc_cpufreq.c:123 cppc_scale_freq_workfn+0xc8/0xf8 [ 24.893901] Modules linked in: [ 24.893906] CPU: 95 PID: 1442 Comm: cppc_fie Not tainted 5.13.0-rc6+ #359 [ 24.893910] Hardware name: To be filled by O.E.M. Saber/Saber, BIOS 0ACKL026 03/19/2019 [ 24.893912] pstate: 20400009 (nzCv daif +PAN -UAO -TCO BTYPE=--) [ 24.893915] pc : cppc_scale_freq_workfn+0xc8/0xf8 [ 24.893918] lr : cppc_scale_freq_workfn+0x5c/0xf8 [ 24.893921] sp : ffff80003727bd90 [ 24.893922] x29: ffff80003727bd90 x28: 0000000000000000 x27: ffff800010ec2000 [ 24.893928] x26: ffff800010ec2000 x25: ffff8000107c3d90 x24: 0000000000000001 [ 24.893932] x23: ffff000816244880 x22: ffff8000113f9000 x21: ffff009f825a0a80 [ 24.893935] x20: ffff009efc394220 x19: ffff800011199000 x18: 000000000000001b [ 24.893939] x17: 0000000000000007 x16: 0000000000000001 x15: 00000000000000bf [ 24.893943] x14: 0000000000000016 x13: 000000000000029b x12: 0000000000000016 [ 24.893946] x11: 0000000000000000 x10: 0000000000000000 x9 : ffff009efc6958c0 [ 24.893950] x8 : ffff009efc394248 x7 : 0000000002bde780 x6 : 00000000ffffffff [ 24.893954] x5 : 00000000916e502a x4 : 00000000d9730e80 x3 : ffffffffffffffff [ 24.893958] x2 : 00000000001e8480 x1 : 00000000002625a0 x0 : 0000000000000401 [ 24.893962] Call trace: [ 24.893964] cppc_scale_freq_workfn+0xc8/0xf8 [ 24.893967] kthread_worker_fn+0x110/0x318 [ 24.893971] kthread+0xf4/0x120 [ 24.893973] ret_from_fork+0x10/0x18 [ 24.893977] ---[ end trace ea6dbaf832bce3e4 ]--- > > Meanwhile it is up for review. Ideally I would like to get this merged for 5.14, > but lets see how it goes. > > Thanks. > > -- > Viresh > > Viresh Kumar (3): > cpufreq: Add start_cpu() and stop_cpu() callbacks > arch_topology: Avoid use-after-free for scale_freq_data > cpufreq: CPPC: Add support for frequency invariance > > Documentation/cpu-freq/cpu-drivers.rst | 7 +- > drivers/base/arch_topology.c | 27 ++- > drivers/cpufreq/Kconfig.arm | 10 ++ > drivers/cpufreq/cppc_cpufreq.c | 232 +++++++++++++++++++++++-- > drivers/cpufreq/cpufreq.c | 19 +- > include/linux/arch_topology.h | 1 + > include/linux/cpufreq.h | 5 +- > kernel/sched/core.c | 1 + > 8 files changed, 272 insertions(+), 30 deletions(-) > > -- > 2.31.1.272.g89b43f80a514 >
