From: Sergei Trofimovich <slyfox@gentoo.org>
To: Vlastimil Babka <vbabka@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@redhat.com>,
Andrey Konovalov <andreyknvl@gmail.com>
Cc: linux-kernel@vger.kernel.org,
Sergei Trofimovich <slyfox@gentoo.org>,
linux-mm@kvack.org
Subject: [PATCH v2] mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1
Date: Sat, 27 Mar 2021 18:21:44 +0000 [thread overview]
Message-ID: <20210327182144.3213887-1-slyfox@gentoo.org> (raw)
In-Reply-To: <20210327180348.137d8fe2@sf>
On !ARCH_SUPPORTS_DEBUG_PAGEALLOC (like ia64) debug_pagealloc=1
implies page_poison=on:
if (page_poisoning_enabled() ||
(!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
debug_pagealloc_enabled()))
static_branch_enable(&_page_poisoning_enabled);
page_poison=on needs to init_on_free=1.
Before the change id happened too late for the following case:
- have PAGE_POISONING=y
- have page_poison unset
- have !ARCH_SUPPORTS_DEBUG_PAGEALLOC arch (like ia64)
- have init_on_free=1
- have debug_pagealloc=1
That way we get both keys enabled:
- static_branch_enable(&init_on_free);
- static_branch_enable(&_page_poisoning_enabled);
which leads to poisoned pages returned for __GFP_ZERO pages.
After the change we execute only:
- static_branch_enable(&_page_poisoning_enabled);
and ignore init_on_free=1.
CC: Vlastimil Babka <vbabka@suse.cz>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: linux-mm@kvack.org
CC: David Hildenbrand <david@redhat.com>
CC: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lkml.org/lkml/2021/3/26/443
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
---
mm/page_alloc.c | 30 +++++++++++++++++-------------
1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d57d9b4f7089..10a8a1d28c11 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -764,32 +764,36 @@ static inline void clear_page_guard(struct zone *zone, struct page *page,
*/
void init_mem_debugging_and_hardening(void)
{
+ bool page_poison_requested = page_poisoning_enabled();
+
+#ifdef CONFIG_PAGE_POISONING
+ /*
+ * Page poisoning is debug page alloc for some arches. If
+ * either of those options are enabled, enable poisoning.
+ */
+ if (page_poisoning_enabled() ||
+ (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
+ debug_pagealloc_enabled())) {
+ static_branch_enable(&_page_poisoning_enabled);
+ page_poison_requested = true;
+ }
+#endif
+
if (_init_on_alloc_enabled_early) {
- if (page_poisoning_enabled())
+ if (page_poison_requested)
pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
"will take precedence over init_on_alloc\n");
else
static_branch_enable(&init_on_alloc);
}
if (_init_on_free_enabled_early) {
- if (page_poisoning_enabled())
+ if (page_poison_requested)
pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
"will take precedence over init_on_free\n");
else
static_branch_enable(&init_on_free);
}
-#ifdef CONFIG_PAGE_POISONING
- /*
- * Page poisoning is debug page alloc for some arches. If
- * either of those options are enabled, enable poisoning.
- */
- if (page_poisoning_enabled() ||
- (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
- debug_pagealloc_enabled()))
- static_branch_enable(&_page_poisoning_enabled);
-#endif
-
#ifdef CONFIG_DEBUG_PAGEALLOC
if (!debug_pagealloc_enabled())
return;
--
2.31.0
next prev parent reply other threads:[~2021-03-27 18:22 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-26 11:26 [PATCH] mm: page_alloc: ignore init_on_free=1 for page alloc Sergei Trofimovich
2021-03-26 13:48 ` David Hildenbrand
2021-03-26 15:00 ` Andrey Konovalov
2021-03-26 16:42 ` Sergei Trofimovich
2021-03-29 12:10 ` Vlastimil Babka
2021-03-29 22:00 ` Andrey Konovalov
2021-03-29 22:07 ` Vlastimil Babka
2021-03-30 14:48 ` Andrey Konovalov
2021-03-26 14:17 ` Vlastimil Babka
2021-03-26 17:25 ` Sergei Trofimovich
2021-03-27 18:03 ` Sergei Trofimovich
2021-03-27 18:21 ` Sergei Trofimovich [this message]
2021-03-29 9:23 ` [PATCH v2] mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1 David Hildenbrand
2021-03-29 11:59 ` Vlastimil Babka
2021-03-29 22:25 ` [PATCH v3] " Sergei Trofimovich
2021-03-30 8:39 ` David Hildenbrand
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