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Message-ID: <c038e06504733e8dc6830f082c8522c60895fd8e.camel@perches.com>
Subject: Re: [RFC v2 3/3] mm, printk: introduce new format %pGt for page_type
From:   Joe Perches <joe@perches.com>
To:     Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
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Date:   Sun, 06 Nov 2022 10:04:25 -0800
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On Sun, 2022-11-06 at 23:03 +0900, Hyeonggon Yoo wrote:
> dump_page() uses %pGp format to print 'flags' field of struct page.
> As some page flags (e.g. PG_buddy, see page-flags.h for more details)
> are set in page_type field, introduce %pGt format which provides
> human readable output of page_type. And use it in dump_page().
[]
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
[]
> @@ -2056,6 +2056,28 @@ char *format_page_flags(char *buf, char *end, unsigned long flags)
>  	return buf;
>  }
>  
> +static

noinline_for_stack ?

> +char *format_page_type(char *buf, char *end, unsigned int page_type)
> +{
> +	if (!(page_type & PAGE_TYPE_BASE))
> +		return string(buf, end, "no type for user-mapped page", default_str_spec);

Might be better with something like '%pGt: no type..."