ich777/linux_media
1
0
Fork 0
mirror of https://github.com/tbsdtv/linux_media.git synced 2025-07-23 12:43:29 +02:00
Code Issues Packages Projects Releases Wiki Activity

mm, printk: introduce new format %pGt for page_type

Browse Source 
%pGp format is used to display 'flags' field of a struct page.  However,
some page flags (i.e.  PG_buddy, see page-flags.h for more details) are
stored in page_type field.  To display human-readable output of page_type,
introduce %pGt format.

It is important to note the meaning of bits are different in page_type. 
if page_type is 0xffffffff, no flags are set.  Setting PG_buddy
(0x00000080) flag results in a page_type of 0xffffff7f.  Clearing a bit
actually means setting a flag.  Bits in page_type are inverted when
displaying type names.

Only values for which page_type_has_type() returns true are considered as
page_type, to avoid confusion with mapcount values.  if it returns false,
only raw values are displayed and not page type names.

Link: https://lkml.kernel.org/r/20230130042514.2418-3-42.hyeyoo@gmail.com
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>	[vsprintf part]
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Hyeonggon Yoo
2023-01-30 13:25:13 +09:00
committed by Andrew Morton
parent e26fcc02c7
commit 4c85c0be3d
7 changed files with 78 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
lib/vsprintf.c
View File

@@ -2052,6 +2052,25 @@ char *format_page_flags(char *buf, char *end, unsigned long flags)
return buf;
}
static
char *format_page_type(char *buf, char *end, unsigned int page_type)
{
buf = number(buf, end, page_type, default_flag_spec);
if (buf < end)
*buf = '(';
buf++;
if (page_type_has_type(page_type))
buf = format_flags(buf, end, ~page_type, pagetype_names);
if (buf < end)
*buf = ')';
buf++;
return buf;
}
static noinline_for_stack
char *flags_string(char *buf, char *end, void *flags_ptr,
struct printf_spec spec, const char *fmt)
@@ -2065,6 +2084,8 @@ char *flags_string(char *buf, char *end, void *flags_ptr,
switch (fmt[1]) {
case 'p':
return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
case 't':
return format_page_type(buf, end, *(unsigned int *)flags_ptr);
case 'v':
flags = *(unsigned long *)flags_ptr;
names = vmaflag_names;