diff options
| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2016-03-15 14:55:30 -0700 |
|---|---|---|
| committer | Kyle Yan <kyan@codeaurora.org> | 2016-04-29 14:40:10 -0700 |
| commit | 9194c460b811af1ea987b72926c970a6fb2e1063 (patch) | |
| tree | 2b37e80e517aca49bcef731ec2b4d5448dae9cef /mm/page_alloc.c | |
| parent | 1b1799f4980d4ae699e8e11b3a30db432890987a (diff) | |
mm/debug_pagealloc: ask users for default setting of debug_pagealloc
Since commit 031bc5743f158 ("mm/debug-pagealloc: make debug-pagealloc
boottime configurable") CONFIG_DEBUG_PAGEALLOC is by default not adding
any page debugging.
This resulted in several unnoticed bugs, e.g.
https://lkml.kernel.org/g/<569F5E29.3090107@de.ibm.com>
or
https://lkml.kernel.org/g/<56A20F30.4050705@de.ibm.com>
as this behaviour change was not even documented in Kconfig.
Let's provide a new Kconfig symbol that allows to change the default
back to enabled, e.g. for debug kernels. This also makes the change
obvious to kernel packagers.
Let's also change the Kconfig description for CONFIG_DEBUG_PAGEALLOC, to
indicate that there are two stages of overhead.
CRs-Fixed: 1006743
Change-Id: I52c36765837cc873877b9398371ffd840d485a81
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: ea6eabb05b26bd3d6f60b29b77a03bc61479fc0f
Git-repo: git://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index cadce191d555..01b4412d08f0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -491,7 +491,8 @@ void prep_compound_page(struct page *page, unsigned int order) #ifdef CONFIG_DEBUG_PAGEALLOC unsigned int _debug_guardpage_minorder; -bool _debug_pagealloc_enabled __read_mostly; +bool _debug_pagealloc_enabled __read_mostly + = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT); bool _debug_guardpage_enabled __read_mostly; static int __init early_debug_pagealloc(char *buf) @@ -502,6 +503,9 @@ static int __init early_debug_pagealloc(char *buf) if (strcmp(buf, "on") == 0) _debug_pagealloc_enabled = true; + if (strcmp(buf, "off") == 0) + _debug_pagealloc_enabled = false; + return 0; } early_param("debug_pagealloc", early_debug_pagealloc); |