On 20/05/2020 10:51, Marc Zyngier wrote:
Hi John,
On 2020-05-20 09:43, John Garry wrote:
On 19/05/2020 23:09, Qian Cai wrote:
Reverted the linux-next commit f068a62c548c ("irqchip/gic-v3-its:
Balance initial LPI affinity across CPUs") fixed these warnings during
boot,
Thanks for the notice. So we need the following set to see this:
CONFIG_CPUMASK_OFFSTACK=y
CONFIG_DEBUG_ATOMIC_SLEEP=y
CONFIG_DEBUG_PER_CPU_MAPS=y
Ah, thanks for pointing this out.
its_select_cpu at drivers/irqchip/irq-gic-v3-its.c:1572
[ 332.819381][ T3359] BUG: sleeping function called from invalid
context at mm/slab.h:568
[ 332.827405][ T3359] in_atomic(): 1, irqs_disabled(): 128,
non_block: 0, pid: 3359, name: irqbalance
[ 332.836455][ T3359] INFO: lockdep is turned off.
[ 332.841076][ T3359] irq event stamp: 0
[ 332.844836][ T3359] hardirqs last enabled at (0):
[<0000000000000000>] 0x0
[ 332.851828][ T3359] hardirqs last disabled at (0):
[<ffff9000101ea65c>] copy_process+0x98c/0x1f34
[ 332.860710][ T3359] softirqs last enabled at (0):
[<ffff9000101ea690>] copy_process+0x9c0/0x1f34
[ 332.869586][ T3359] softirqs last disabled at (0):
[<0000000000000000>] 0x0
[ 332.876560][ T3359] CPU: 155 PID: 3359 Comm: irqbalance Tainted: G
W L 5.7.0-rc6-next-20200519 #1
[ 332.886563][ T3359] Hardware name: HPE Apollo 70
/C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019
[ 332.897000][ T3359] Call trace:
[ 332.900151][ T3359] dump_backtrace+0x0/0x22c
[ 332.904514][ T3359] show_stack+0x28/0x34
[ 332.908543][ T3359] dump_stack+0x104/0x194
[ 332.912738][ T3359] ___might_sleep+0x314/0x328
[ 332.917274][ T3359] __might_sleep+0x7c/0xe0
[ 332.921563][ T3359] slab_pre_alloc_hook+0x44/0x8c
[ 332.926360][ T3359] __kmalloc_node+0xb0/0x618
[ 332.930811][ T3359] alloc_cpumask_var_node+0x48/0x94
We could use GFP_ATOMIC flag at the callsite here, but maybe there is
a better solution.
I don't see one, and I doubt it is worth the hassle to have anything
but GFP_ATOMIC. The default arm64 config is to have on-stack cpumasks,
and only DEBUG_PER_CPU_MAPS allows this to be changed.
JFYI, I was able to recreate on my D05:
[11.951739] CPU: 21 PID: 1 Comm: swapper/0 Tainted: G
W5.7.0-rc6-next-20200519-dirty #16
[11.961262] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05
IT21 Nemo 2.0 RC0 04/18/2018
[11.970435] Call trace:
[11.972890] dump_backtrace+0x0/0x1b0
[11.976561] show_stack+0x14/0x1c
[11.979884] dump_stack+0xc0/0xf0
[11.983207] ___might_sleep+0x10c/0x12c
[11.987052] __might_sleep+0x4c/0x80
[11.990637] __kmalloc_node+0x1ac/0x2dc
[11.994483] alloc_cpumask_var_node+0x28/0x60
[11.998852] alloc_cpumask_var+0x10/0x18
[12.002787] its_select_cpu+0x2c/0x19c
[12.006546] its_irq_domain_activate+0x38/0xf0
[12.011004] __irq_domain_activate_irq+0x6c/0xac
[12.011108] sd 0:0:7:0: [sdh] Attached SCSI disk
[12.015636] __irq_domain_activate_irq+0x34/0xac
[12.015638] __irq_domain_activate_irq+0x34/0xac
[12.015640] irq_domain_activate_irq+0x3c/0x4c
[12.015643] irq_activate+0x20/0x30
[12.037482] __setup_irq+0x538/0x6ec
[12.041065] request_threaded_irq+0xdc/0x18c
[12.045350] usb_add_hcd+0x4b0/0x6c0
[12.048934] ehci_platform_probe+0x1f4/0x438
[12.053218] platform_drv_probe+0x4c/0xa0
[12.057239] really_probe+0xf4/0x35c
[12.060823] driver_probe_device+0x54/0xb0
[12.064931] device_driver_attach+0x68/0x70
[12.069126] __driver_attach+0x9c/0xf8
[12.072884] bus_for_each_dev+0x50/0xa0
[12.076730] driver_attach+0x20/0x28
[12.080313] bus_add_driver+0x148/0x1fc
[12.084159] driver_register+0x6c/0x124
[12.088005] __platform_driver_register+0x48/0x50
[12.092727] ehci_platform_init+0x54/0x64
[12.096747] do_one_initcall+0x50/0x194
[12.100593] kernel_init_freeable+0x1e4/0x250
[12.104964] kernel_init+0x10/0x108
[12.108460] ret_from_fork+0x10/0x18
[12.112077] ehci-platform PNP0D20:00: irq 361, io mem 0xa7020000
And setting GFP_ATOMIC removes that BUG.
Cheers,
John
