The patch titled
Subject: x86: query dynamic DEBUG_PAGEALLOC setting
has been added to the -mm tree. Its filename is
x86-query-dynamic-debug_pagealloc-setting.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/x86-query-dynamic-debug_pagealloc-setting.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/x86-query-dynamic-debug_pagealloc-setting.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Subject: x86: query dynamic DEBUG_PAGEALLOC setting
We can use debug_pagealloc_enabled() to check if we can map the identity
mapping with 2MB pages. We can also add the state into the dump_stack
output.
The patch does not touch the code for the 1GB pages, which ignored
CONFIG_DEBUG_PAGEALLOC. Do we need to fence this as well?
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Laura Abbott <labbott@xxxxxxxxxxxxxxxxx>
Cc: Joonsoo Kim <js1304@xxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/dumpstack.c | 5 ++---
arch/x86/mm/init.c | 7 ++++---
arch/x86/mm/pageattr.c | 14 ++++----------
3 files changed, 10 insertions(+), 16 deletions(-)
diff -puN arch/x86/kernel/dumpstack.c~x86-query-dynamic-debug_pagealloc-setting arch/x86/kernel/dumpstack.c
--- a/arch/x86/kernel/dumpstack.c~x86-query-dynamic-debug_pagealloc-setting
+++ a/arch/x86/kernel/dumpstack.c
@@ -265,9 +265,8 @@ int __die(const char *str, struct pt_reg
#ifdef CONFIG_SMP
printk("SMP ");
#endif
-#ifdef CONFIG_DEBUG_PAGEALLOC
- printk("DEBUG_PAGEALLOC ");
-#endif
+ if (debug_pagealloc_enabled())
+ printk("DEBUG_PAGEALLOC ");
#ifdef CONFIG_KASAN
printk("KASAN");
#endif
diff -puN arch/x86/mm/init.c~x86-query-dynamic-debug_pagealloc-setting arch/x86/mm/init.c
--- a/arch/x86/mm/init.c~x86-query-dynamic-debug_pagealloc-setting
+++ a/arch/x86/mm/init.c
@@ -150,13 +150,14 @@ static int page_size_mask;
static void __init probe_page_size_mask(void)
{
-#if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK)
+#if !defined(CONFIG_KMEMCHECK)
/*
- * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
+ * For CONFIG_KMEMCHECK or pagealloc debugging, identity mapping will
+ * use small pages.
* This will simplify cpa(), which otherwise needs to support splitting
* large pages into small in interrupt context, etc.
*/
- if (cpu_has_pse)
+ if (cpu_has_pse && !debug_pagealloc_enabled())
page_size_mask |= 1 << PG_LEVEL_2M;
#endif
diff -puN arch/x86/mm/pageattr.c~x86-query-dynamic-debug_pagealloc-setting arch/x86/mm/pageattr.c
--- a/arch/x86/mm/pageattr.c~x86-query-dynamic-debug_pagealloc-setting
+++ a/arch/x86/mm/pageattr.c
@@ -106,12 +106,6 @@ static inline unsigned long highmap_end_
#endif
-#ifdef CONFIG_DEBUG_PAGEALLOC
-# define debug_pagealloc 1
-#else
-# define debug_pagealloc 0
-#endif
-
static inline int
within(unsigned long addr, unsigned long start, unsigned long end)
{
@@ -708,10 +702,10 @@ static int split_large_page(struct cpa_d
{
struct page *base;
- if (!debug_pagealloc)
+ if (!debug_pagealloc_enabled())
spin_unlock(&cpa_lock);
base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
- if (!debug_pagealloc)
+ if (!debug_pagealloc_enabled())
spin_lock(&cpa_lock);
if (!base)
return -ENOMEM;
@@ -1331,10 +1325,10 @@ static int __change_page_attr_set_clr(st
if (cpa->flags & (CPA_ARRAY | CPA_PAGES_ARRAY))
cpa->numpages = 1;
- if (!debug_pagealloc)
+ if (!debug_pagealloc_enabled())
spin_lock(&cpa_lock);
ret = __change_page_attr(cpa, checkalias);
- if (!debug_pagealloc)
+ if (!debug_pagealloc_enabled())
spin_unlock(&cpa_lock);
if (ret)
return ret;
_
Patches currently in -mm which might be from borntraeger@xxxxxxxxxx are
mm-debug_pagealloc-ask-users-for-default-setting-of-debug_pagealloc.patch
mm-debug_pagealloc-ask-users-for-default-setting-of-debug_pagealloc-v3.patch
x86-query-dynamic-debug_pagealloc-setting.patch
s390-query-dynamic-debug_pagealloc-setting.patch
x86-also-use-debug_pagealloc_enabled-for-free_init_pages.patch
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