mm, arch: remove empty_bad_page*

empty_bad_page() and empty_bad_pte_table() seem to be relics from old
days which is not used by any code for a long time.  I have tried to
find when exactly but this is not really all that straightforward due to
many code movements - traces disappear around 2.4 times.

Anyway no code really references neither empty_bad_page nor
empty_bad_pte_table.  We only allocate the storage which is not used by
anybody so remove them.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Ralf Baechle <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: David Howells <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Richard Weinberger <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Michal Hocko 2017-11-15 17:34:22 -08:00 • committed by Linus Torvalds
commit 8745808fda
7 changed files with 2 additions and 54 deletions

View file

@ -42,21 +42,9 @@
#undef DEBUG
/*
* BAD_PAGE is the page that is used for page faults when linux
* is out-of-memory. Older versions of linux just did a
* do_exit(), but using this instead means there is less risk
* for a process dying in kernel mode, possibly leaving a inode
* unused etc..
*
* BAD_PAGETABLE is the accompanying page-table: it is initialized
* to point to BAD_PAGE entries.
*
* ZERO_PAGE is a special page that is used for zero-initialized
* data and COW.
*/
static unsigned long empty_bad_page_table;
static unsigned long empty_bad_page;
unsigned long empty_zero_page;
EXPORT_SYMBOL(empty_zero_page);
@ -72,8 +60,6 @@ void __init paging_init(void)
unsigned long zones_size[MAX_NR_ZONES] = {0, };
/* allocate some pages for kernel housekeeping tasks */
empty_bad_page_table = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
empty_bad_page = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
empty_zero_page = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
memset((void *) empty_zero_page, 0, PAGE_SIZE);