2022-07-14 09:24:07

by Huacai Chen

Subject: [PATCH V2 1/3] MIPS: cpuinfo: Fix a warning for CONFIG_CPUMASK_OFFSTACK

When CONFIG_CPUMASK_OFFSTACK and CONFIG_DEBUG_PER_CPU_MAPS is selected,
cpu_max_bits_warn() generates a runtime warning similar as below while
we show /proc/cpuinfo. Fix this by using nr_cpu_ids (the runtime limit)
instead of NR_CPUS to iterate CPUs.

[ 3.052463] ------------[ cut here ]------------
[ 3.059679] WARNING: CPU: 3 PID: 1 at include/linux/cpumask.h:108 show_cpuinfo+0x5e8/0x5f0
[ 3.070072] Modules linked in: efivarfs autofs4
[ 3.076257] CPU: 0 PID: 1 Comm: systemd Not tainted 5.19-rc5+ #1052
[ 3.084034] Hardware name: Loongson Loongson-3A4000-7A1000-1w-V0.1-CRB/Loongson-LS3A4000-7A1000-1w-EVB-V1.21, BIOS Loongson-UDK2018-V2.0.04082-beta7 04/27
[ 3.099465] Stack : 9000000100157b08 9000000000f18530 9000000000cf846c 9000000100154000
[ 3.109127] 9000000100157a50 0000000000000000 9000000100157a58 9000000000ef7430
[ 3.118774] 90000001001578e8 0000000000000040 0000000000000020 ffffffffffffffff
[ 3.128412] 0000000000aaaaaa 1ab25f00eec96a37 900000010021de80 900000000101c890
[ 3.138056] 0000000000000000 0000000000000000 0000000000000000 0000000000aaaaaa
[ 3.147711] ffff8000339dc220 0000000000000001 0000000006ab4000 0000000000000000
[ 3.157364] 900000000101c998 0000000000000004 9000000000ef7430 0000000000000000
[ 3.167012] 0000000000000009 000000000000006c 0000000000000000 0000000000000000
[ 3.176641] 9000000000d3de08 9000000001639390 90000000002086d8 00007ffff0080286
[ 3.186260] 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c
[ 3.195868] ...
[ 3.199917] Call Trace:
[ 3.203941] [<98000000002086d8>] show_stack+0x38/0x14c
[ 3.210666] [<9800000000cf846c>] dump_stack_lvl+0x60/0x88
[ 3.217625] [<980000000023d268>] __warn+0xd0/0x100
[ 3.223958] [<9800000000cf3c90>] warn_slowpath_fmt+0x7c/0xcc
[ 3.231150] [<9800000000210220>] show_cpuinfo+0x5e8/0x5f0
[ 3.238080] [<98000000004f578c>] seq_read_iter+0x354/0x4b4
[ 3.245098] [<98000000004c2e90>] new_sync_read+0x17c/0x1c4
[ 3.252114] [<98000000004c5174>] vfs_read+0x138/0x1d0
[ 3.258694] [<98000000004c55f8>] ksys_read+0x70/0x100
[ 3.265265] [<9800000000cfde9c>] do_syscall+0x7c/0x94
[ 3.271820] [<9800000000202fe4>] handle_syscall+0xc4/0x160
[ 3.281824] ---[ end trace 8b484262b4b8c24c ]---

Cc: [email protected]
Signed-off-by: Huacai Chen <[email protected]>
---
arch/mips/kernel/proc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kernel/proc.c b/arch/mips/kernel/proc.c
index 4184d641f05e..33a02f3814f5 100644
--- a/arch/mips/kernel/proc.c
+++ b/arch/mips/kernel/proc.c
@@ -172,7 +172,7 @@ static void *c_start(struct seq_file *m, loff_t *pos)
{
unsigned long i = *pos;

- return i < NR_CPUS ? (void *) (i + 1) : NULL;
+ return i < nr_cpu_ids ? (void *) (i + 1) : NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t *pos)
--
2.31.1

2022-07-14 10:03:08

by Thomas Bogendoerfer

Subject: Re: [PATCH V2 1/3] MIPS: cpuinfo: Fix a warning for CONFIG_CPUMASK_OFFSTACK

On Thu, Jul 14, 2022 at 04:41:34PM +0800, Huacai Chen wrote:
> When CONFIG_CPUMASK_OFFSTACK and CONFIG_DEBUG_PER_CPU_MAPS is selected,
> cpu_max_bits_warn() generates a runtime warning similar as below while
> we show /proc/cpuinfo. Fix this by using nr_cpu_ids (the runtime limit)
> instead of NR_CPUS to iterate CPUs.
>
> [ 3.052463] ------------[ cut here ]------------
> [ 3.059679] WARNING: CPU: 3 PID: 1 at include/linux/cpumask.h:108 show_cpuinfo+0x5e8/0x5f0
> [ 3.070072] Modules linked in: efivarfs autofs4
> [ 3.076257] CPU: 0 PID: 1 Comm: systemd Not tainted 5.19-rc5+ #1052
> [ 3.084034] Hardware name: Loongson Loongson-3A4000-7A1000-1w-V0.1-CRB/Loongson-LS3A4000-7A1000-1w-EVB-V1.21, BIOS Loongson-UDK2018-V2.0.04082-beta7 04/27
> [ 3.099465] Stack : 9000000100157b08 9000000000f18530 9000000000cf846c 9000000100154000
> [ 3.109127] 9000000100157a50 0000000000000000 9000000100157a58 9000000000ef7430
> [ 3.118774] 90000001001578e8 0000000000000040 0000000000000020 ffffffffffffffff
> [ 3.128412] 0000000000aaaaaa 1ab25f00eec96a37 900000010021de80 900000000101c890
> [ 3.138056] 0000000000000000 0000000000000000 0000000000000000 0000000000aaaaaa
> [ 3.147711] ffff8000339dc220 0000000000000001 0000000006ab4000 0000000000000000
> [ 3.157364] 900000000101c998 0000000000000004 9000000000ef7430 0000000000000000
> [ 3.167012] 0000000000000009 000000000000006c 0000000000000000 0000000000000000
> [ 3.176641] 9000000000d3de08 9000000001639390 90000000002086d8 00007ffff0080286
> [ 3.186260] 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c
> [ 3.195868] ...
> [ 3.199917] Call Trace:
> [ 3.203941] [<98000000002086d8>] show_stack+0x38/0x14c
> [ 3.210666] [<9800000000cf846c>] dump_stack_lvl+0x60/0x88
> [ 3.217625] [<980000000023d268>] __warn+0xd0/0x100
> [ 3.223958] [<9800000000cf3c90>] warn_slowpath_fmt+0x7c/0xcc
> [ 3.231150] [<9800000000210220>] show_cpuinfo+0x5e8/0x5f0
> [ 3.238080] [<98000000004f578c>] seq_read_iter+0x354/0x4b4
> [ 3.245098] [<98000000004c2e90>] new_sync_read+0x17c/0x1c4
> [ 3.252114] [<98000000004c5174>] vfs_read+0x138/0x1d0
> [ 3.258694] [<98000000004c55f8>] ksys_read+0x70/0x100
> [ 3.265265] [<9800000000cfde9c>] do_syscall+0x7c/0x94
> [ 3.271820] [<9800000000202fe4>] handle_syscall+0xc4/0x160
> [ 3.281824] ---[ end trace 8b484262b4b8c24c ]---
>
> Cc: [email protected]
> Signed-off-by: Huacai Chen <[email protected]>
> ---
> arch/mips/kernel/proc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

applied to mips-next.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]