Re: [PATCH] introduce boot_printk()

Yinghai Lu
2008-09-16T18:10:47Z

On Tue, Sep 16, 2008 at 10:53 AM, H. Peter Anvin <hpa@zytor.com> wrote:
> Yinghai Lu wrote:
>>
>> it seem using pci_printk or acpi_printk.. could be more flexible.
>>
>> otherwise will need to keep update linux/kernel.h to add so call subsys
>> tags...
>>
>> use only need to
>> have DEFINE_LOGLEVEL_SETUP(xxx) in c
>> and have DECLARE_LOGLEVEL(xxx) in .h
>> then just use xxx_printk
>>
>
> Uh? You can add the subsys tags elsewhere if you prefer too.
>
> However, there are a few important differences to keep in mind. Tags get
> logged in the dmesg buffer even if not printed to the kernel, whereas a
> jump-based architecture will not just suppress the output, but even the
> formatting of the output. Either is a good thing for certain things, and a
> bad thing for other things.
>
> I personally think the kind of things discussed belong in the category of
> "always put in the dmesg buffer", and like the idea of subsystem-tagging
> them.
>

you still can use
pci_printk(v, KERN_PCI KERN_DEBUG "...\n");

if vprintk is expanded to handle KERN_PCI and other tags...
or even you could use
pci_printk(v, KERN_ACPI KERN_DEBUG "...\n");

YH