Re: [PATCH] Revert "cpumask: fix checking valid cpu range"

[Guo Ren]

On Tue, Oct 18, 2022 at 3:53 AM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>
> On Mon, 17 Oct 2022 10:56:05 +0800 Guo Ren wrote:
> > Ping Jakub Kicinski <kuba@xxxxxxxxxx>.
> >
> > You seem to miss this Revert fixup on cpumask_check(n + 1).
> >
> > Your patch has merged in v6.1-rc1, but that is not enough.
> > https://lore.kernel.org/netdev/166582921612.1299.769135677399153914.git-patchwork-notify@xxxxxxxxxx/T/#m0111a76380626b2f91e072ecdd5827578d5cbf60
> >
> > Without the patch, there still is a warning.
>
> Sorry, I don't know what you mean. I was only putting a workaround back
> into the core networking code - I'm guessing this patch will silence
> the warning that comes from virtio? I haven't looked into that one.

Without the patch, Linux-v6.1-rc1 would warn when
CONFIG_DEBUG_PER_CPU_MAPS was enabled.

[    2.130438] virtio_blk virtio0: 1/0/0 default/read/poll queues
[    2.137585] virtio_blk virtio0: [vda] 122880 512-byte logical
blocks (62.9 MB/60.0 MiB)
[    2.196181] lkdtm: No crash points registered, enable through debugfs
[    2.246658] ------------[ cut here ]------------
[    2.247468] WARNING: CPU: 3 PID: 1 at include/linux/cpumask.h:110
__netif_set_xps_queue+0x14e/0x792
[    2.248738] Modules linked in:
[    2.249323] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc1 #336
[    2.250038] Hardware name: riscv-virtio,qemu (DT)
[    2.250697] epc : __netif_set_xps_queue+0x14e/0x792
[    2.251538]  ra : __netif_set_xps_queue+0x56c/0x792
[    2.252029] epc : ffffffff806f2972 ra : ffffffff806f2d90 sp :
ff600000023279d0
[    2.252664]  gp : ffffffff81603d88 tp : ff600000023a0000 t0 :
ff60000003068a40
[    2.253270]  t1 : 0000000000000003 t2 : 0000000000000000 s0 :
ff60000002327a90
[    2.253878]  s1 : 0000000000000000 a0 : ff60000003068a00 a1 :
ff60000003068a00
[    2.254491]  a2 : ff600000030687e8 a3 : 0000000000000004 a4 :
0000000000000000
[    2.255521]  a5 : 0000000000000000 a6 : 0000000000000000 a7 :
0000000000000000
[    2.256506]  s2 : 0000000000000000 s3 : 0000000000000000 s4 :
ff60000002327aa0
[    2.257161]  s5 : ffffffff816071c0 s6 : 0000000000000000 s7 :
0000000000000001
[    2.257761]  s8 : 0000000000000000 s9 : 0000000000000004 s10:
ff600000030687c0
[    2.258369]  s11: 0000000000000004 t3 : 0000000000000000 t4 :
0000000000000014
[    2.259368]  t5 : 0000000000000000 t6 : 0000000000000000
[    2.260270] status: 0000000200000120 badaddr: 0000000000000000
cause: 0000000000000003
[    2.261200] [<ffffffff805d941e>] virtnet_set_affinity+0x14a/0x1c0
[    2.261837] [<ffffffff805db734>] virtnet_probe+0x832/0xf1e
[    2.262319] [<ffffffff804ff5d0>] virtio_dev_probe+0x164/0x2de
[    2.263055] [<ffffffff8054d478>] really_probe+0x82/0x224
[    2.263858] [<ffffffff8054d674>] __driver_probe_device+0x5a/0xaa
[    2.264445] [<ffffffff8054d6f0>] driver_probe_device+0x2c/0xb8
[    2.264987] [<ffffffff8054dd1a>] __driver_attach+0x76/0x108
[    2.265495] [<ffffffff8054b436>] bus_for_each_dev+0x52/0x9a
[    2.265996] [<ffffffff8054ce40>] driver_attach+0x1a/0x28
[    2.266475] [<ffffffff8054c94a>] bus_add_driver+0x154/0x1c2
[    2.267383] [<ffffffff8054e546>] driver_register+0x52/0x108
[    2.268198] [<ffffffff804ff0d4>] register_virtio_driver+0x1c/0x2c
[    2.268778] [<ffffffff80a291a0>] virtio_net_driver_init+0x7a/0xb0
[    2.269323] [<ffffffff80002854>] do_one_initcall+0x66/0x2e4
[    2.269834] [<ffffffff80a01226>] kernel_init_freeable+0x28a/0x304
[    2.270372] [<ffffffff808cc8b6>] kernel_init+0x1e/0x110
[    2.271099] [<ffffffff80003d42>] ret_from_exception+0x0/0x10
[    2.272015] ---[ end trace 0000000000000000 ]---

-- 
Best Regards
 Guo Ren