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.
I'll stash a patch on top.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
