Commit c02c3009 authored by Yang Shi's avatar Yang Shi Committed by Linus Torvalds
Browse files

mm/madvise.c: add description for MADV_WIPEONFORK and MADV_KEEPONFORK 

mm/madvise.c has a brief description about all MADV_ flags.  Add a
description for the newly added MADV_WIPEONFORK and MADV_KEEPONFORK.

Although man page has the similar information, but it'd better to keep
the consistent with other flags.

Link: http://lkml.kernel.org/r/1506117328-88228-1-git-send-email-yang.s@alibaba-inc.com


Signed-off-by: default avatarYang Shi <yang.s@alibaba-inc.com>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cc3fa840

mm/madvise.c

+6 −1
Original line number Diff line number Diff line
@@ -757,6 +757,9 @@ madvise_behavior_valid(int behavior) 
 *  MADV_DONTFORK - omit this area from child's address space when forking:

 *		typically, to avoid COWing pages pinned by get_user_pages().

 *  MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking.

 *  MADV_WIPEONFORK - present the child process with zero-filled memory in this

 *              range after a fork.

 *  MADV_KEEPONFORK - undo the effect of MADV_WIPEONFORK

 *  MADV_HWPOISON - trigger memory error handler as if the given memory range

 *		were corrupted by unrecoverable hardware memory failure.

 *  MADV_SOFT_OFFLINE - try to soft-offline the given range of memory.
@@ -777,7 +780,9 @@ madvise_behavior_valid(int behavior) 
 *  zero    - success

 *  -EINVAL - start + len < 0, start is not page-aligned,

 *		"behavior" is not a valid value, or application

 *		is attempting to release locked or shared pages.

 *		is attempting to release locked or shared pages,

 *		or the specified address range includes file, Huge TLB,

 *		MAP_SHARED or VMPFNMAP range.

 *  -ENOMEM - addresses in the specified range are not currently

 *		mapped, or are outside the AS of the process.

 *  -EIO    - an I/O error occurred while paging in data.

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