linux-kernel - smpboot: CPU numbers printed as warning

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Message-ID: <e964b2ae-7a15-a510-e76a-56d704949d62@molgen.mpg.de>
Date:   Mon, 15 Feb 2021 20:22:34 +0100
From:   Paul Menzel <pmenzel@...gen.mpg.de>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        x86@...nel.org
Cc:     LKML <linux-kernel@...r.kernel.org>, it+linux-x86@...gen.mpg.de,
        Petr Mladek <pmladek@...e.com>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>
Subject: smpboot: CPU numbers printed as warning

Dear Linux folks,


Using Linux 5.10.13 (and before), looking at the Linux kernel warnings, 
the CPU numbers show up. For example with 12 cpus/threads:

```
$ sudo dmesg --level=warn
[    0.216103]   #2
[    0.220105]   #3
[    0.224103]   #4
[    0.228104]   #5
[    0.232110]   #6
[    0.236101]   #7
[    0.240102]   #8
[    0.244102]   #9
[    0.248100]  #10
[    0.252098]  #11
```

If I am not mistaken, this is from `announce_cpu()` in 
`arch/x86/kernel/smpboot.c`, and the `pr_cont()` in their “forgets” the 
log level it belongs to, maybe because of SMP and other messages are 
printed in between.

```
         if (system_state < SYSTEM_RUNNING) {
                 if (node != current_node) {
                         if (current_node > (-1))
                                 pr_cont("\n");
                         current_node = node;

                         printk(KERN_INFO ".... node %*s#%d, CPUs:  ",
                                node_width - num_digits(node), " ", node);
                 }

                 /* Add padding for the BSP */
                 if (cpu == 1)
                         pr_cont("%*s", width + 1, " ");

                 pr_cont("%*s#%d", width - num_digits(cpu), " ", cpu);

         } else
                 pr_info("Booting Node %d Processor %d APIC 0x%x\n",
                         node, cpu, apicid);
```

Would using `pr_info()` instead be an acceptable fix?


Kind regards,

Paul