On Fri, Mar 08, 2024 at 03:01:28PM +0100, Marek Szyprowski wrote:
> This patch landed in today's linux-next as commit 0499a78369ad ("ARM64:
> Dynamically allocate cpumasks and increase supported CPUs to 512").
> Unfortunately it triggers the following warning during boot on most of
> my ARM64-based test boards. Here is an example from Odroid-N2 board:
>
> ------------[ cut here ]------------
> WARNING: CPU: 4 PID: 63 at drivers/opp/core.c:2554
> dev_pm_opp_set_config+0x390/0x710
> Modules linked in: dw_hdmi_i2s_audio meson_gxl smsc onboard_usb_hub(+)
> rtc_pcf8563 panfrost snd_soc_meson_axg_sound_card drm_shmem_helper
> crct10dif_ce dwmac_generic snd_soc_meson_card_utils gpu_sched
> snd_soc_meson_g12a_toacodec snd_soc_meson_g12a_tohdmitx rc_odroid
> snd_soc_meson_codec_glue pwm_meson ao_cec_g12a meson_gxbb_wdt meson_ir
> snd_soc_meson_axg_frddr snd_soc_meson_axg_toddr snd_soc_meson_axg_tdmin
> meson_vdec(C) v4l2_mem2mem videobuf2_dma_contig snd_soc_meson_axg_tdmout
> videobuf2_memops axg_audio videobuf2_v4l2 sclk_div videodev
> reset_meson_audio_arb snd_soc_meson_axg_fifo clk_phase dwmac_meson8b
> stmmac_platform videobuf2_common mdio_mux_meson_g12a meson_drm
> meson_dw_hdmi rtc_meson_vrtc stmmac meson_ddr_pmu_g12 mc dw_hdmi
> drm_display_helper pcs_xpcs snd_soc_meson_t9015 meson_canvas gpio_fan
> display_connector snd_soc_meson_axg_tdm_interface
> snd_soc_simple_amplifier snd_soc_meson_axg_tdm_formatter nvmem_meson_efuse
> hub 1-1:1.0: USB hub found
> CPU: 4 PID: 63 Comm: kworker/u12:5 Tainted: G C 6.8.0-rc3+ #14677
> Hardware name: Hardkernel ODROID-N2 (DT)
> Workqueue: events_unbound deferred_probe_work_func
> pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : dev_pm_opp_set_config+0x390/0x710
> lr : dev_pm_opp_set_config+0x5c/0x710
> ...
> Call trace:
> dev_pm_opp_set_config+0x390/0x710
> dt_cpufreq_probe+0x268/0x480
> platform_probe+0x68/0xd8
> really_probe+0x148/0x2b4
> __driver_probe_device+0x78/0x12c
> driver_probe_device+0xdc/0x164
> __device_attach_driver+0xb8/0x138
> bus_for_each_drv+0x84/0xe0
> __device_attach+0xa8/0x1b0
> device_initial_probe+0x14/0x20
> bus_probe_device+0xb0/0xb4
> deferred_probe_work_func+0x8c/0xc8
> process_one_work+0x1ec/0x53c
> worker_thread+0x298/0x408
> kthread+0x124/0x128
> ret_from_fork+0x10/0x20
> irq event stamp: 317178
> hardirqs last enabled at (317177): [<ffff8000801788d4>]
> ktime_get_coarse_real_ts64+0x10c/0x110
> hardirqs last disabled at (317178): [<ffff800081222030>] el1_dbg+0x24/0x8c
> softirqs last enabled at (315802): [<ffff800080010a60>]
> __do_softirq+0x4a0/0x4e8
> softirqs last disabled at (315793): [<ffff8000800169b0>]
> ____do_softirq+0x10/0x1c
> ---[ end trace 0000000000000000 ]---
> cpu cpu2: error -EBUSY: failed to set regulators
> cpufreq-dt: probe of cpufreq-dt failed with error -16
>
> It looks that cpufreq-dt and/or opp drivers needs some adjustments
> related with this change.
That's strange. Is this with defconfig? I wonder whether NR_CPUS being
larger caused the issue with this specific code. Otherwise
CPUMASK_OFFSTACK may not work that well on arm64.
>
>
> > ---
> >
> >
> > Original post: https://www.spinics.net/lists/linux-mm/msg369701.html
> > V2: https://lkml.org/lkml/2024/2/7/505
> >
> >
> > V1->V2
> >
> > - Keep quotation marks
> > - Remove whiltespace damage
> > - Add tested by
> >
> > V2->V3:
> > - Add test results
> > - Rework descriptions
> >
> >
> > arch/arm64/Kconfig | 16 +++++++++++++++-
> > 1 file changed, 15 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > index aa7c1d435139..4e767dede47d 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -1427,7 +1427,21 @@ config SCHED_SMT
> > config NR_CPUS
> > int "Maximum number of CPUs (2-4096)"
> > range 2 4096
> > - default "256"
> > + default "512"
> > +
> > +#
> > +# Determines the placement of cpumasks.
> > +#
> > +# With CPUMASK_OFFSTACK the cpumasks are dynamically allocated.
> > +# Useful for machines with lots of core because it avoids increasing
> > +# the size of many of the data structures in the kernel.
> > +#
> > +# If this is off then the cpumasks have a static sizes and are
> > +# embedded within data structures.
> > +#
> > + config CPUMASK_OFFSTACK
> > + def_bool y
> > + depends on NR_CPUS > 256
> >
> > config HOTPLUG_CPU
> > bool "Support for hot-pluggable CPUs"
>
> Best regards
> --
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
>
--
Catalin
