mm: enable page poisoning early at boot
On SPARSEMEM systems page poisoning is enabled after buddy is up, because
of the dependency on page extension init. This causes the pages released
by free_all_bootmem not to be poisoned. This either delays or misses the
identification of some issues because the pages have to undergo another
cycle of alloc-free-alloc for any corruption to be detected.
Enable page poisoning early by getting rid of the PAGE_EXT_DEBUG_POISON
flag. Since all the free pages will now be poisoned, the flag need not be
verified before checking the poison during an alloc.
Link: http://lkml.kernel.org/r/1490358246-11001-1-git-send-email-vinmenon@codeaurora.org
Acked-by: Laura Abbott <labbott@redhat.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[vinmenon@codeaurora.org: resolve trivial merge conflicts.
Remove the redundant free pages RO feature from the
page_poison.c file which is the reason for conflicts +
squash the addendum commit 40961ef8d65f51093bc94de110b97b590b6b9275
('mm-enable-page-poisoning-early-at-boot-v2')]
Git-commit: c5b7cd344fd6341e6db79e55c0f1f4d1d9c67a7e
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
Change-Id: I1bb1f99d3a2e1135131911905e0916c837ba9d8a
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f7a35fd..71450de 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1706,10 +1706,10 @@
return 1;
}
-static inline bool free_pages_prezeroed(bool poisoned)
+static inline bool free_pages_prezeroed(void)
{
return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
- page_poisoning_enabled() && poisoned;
+ page_poisoning_enabled();
}
#ifdef CONFIG_DEBUG_VM
@@ -1763,17 +1763,10 @@
unsigned int alloc_flags)
{
int i;
- bool poisoned = true;
-
- for (i = 0; i < (1 << order); i++) {
- struct page *p = page + i;
- if (poisoned)
- poisoned &= page_is_poisoned(p);
- }
post_alloc_hook(page, order, gfp_flags);
- if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
+ if (!free_pages_prezeroed() && (gfp_flags & __GFP_ZERO))
for (i = 0; i < (1 << order); i++)
clear_highpage(page + i);