From: Christian Borntraeger <borntraeger@de.ibm.com>
To: akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
David Rientjes <rientjes@google.com>,
Christian Borntraeger <borntraeger@de.ibm.com>
Subject: [PATCH v4 2/4] x86: query dynamic DEBUG_PAGEALLOC setting
Date: Wed, 3 Feb 2016 09:39:33 +0100 [thread overview]
Message-ID: <1454488775-108777-8-git-send-email-borntraeger@de.ibm.com> (raw)
In-Reply-To: <1454488775-108777-1-git-send-email-borntraeger@de.ibm.com>
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@de.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
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 --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 9c30acf..32e5699 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -265,9 +265,8 @@ int __die(const char *str, struct pt_regs *regs, long err)
#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 --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 493f541..39823fd 100644
--- a/arch/x86/mm/init.c
+++ b/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 --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 2440814..1ef9c2c 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -106,12 +106,6 @@ static inline unsigned long highmap_end_pfn(void)
#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_data *cpa, pte_t *kpte,
{
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(struct cpa_data *cpa, int checkalias)
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;
--
2.3.0
next prev parent reply other threads:[~2016-02-03 8:40 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 8:39 [PATCH v4 0/4 (resend)] Optimize CONFIG_DEBUG_PAGEALLOC (x86 and s390) Christian Borntraeger
2016-02-03 8:39 ` [PATCH v4 1/4] mm: provide debug_pagealloc_enabled() without CONFIG_DEBUG_PAGEALLOC Christian Borntraeger
2016-02-03 8:39 ` [PATCH v4 2/4] x86: query dynamic DEBUG_PAGEALLOC setting Christian Borntraeger
2016-02-03 22:48 ` David Rientjes
2016-02-03 8:39 ` [PATCH v4 3/4] s390: " Christian Borntraeger
2016-02-03 22:48 ` David Rientjes
2016-02-03 8:39 ` [PATCH v4 4/4] x86: also use debug_pagealloc_enabled() for free_init_pages Christian Borntraeger
2016-02-03 10:43 ` Thomas Gleixner
2016-02-03 22:50 ` David Rientjes
2016-02-03 8:39 ` [PATCH v4 0/4 (resend)] Optimize CONFIG_DEBUG_PAGEALLOC (x86 and s390) Christian Borntraeger
2016-02-03 8:39 ` [PATCH v4 1/4] mm: provide debug_pagealloc_enabled() without CONFIG_DEBUG_PAGEALLOC Christian Borntraeger
2016-02-03 8:39 ` Christian Borntraeger [this message]
2016-02-03 8:39 ` [PATCH v4 3/4] s390: query dynamic DEBUG_PAGEALLOC setting Christian Borntraeger
2016-02-03 8:39 ` [PATCH v4 4/4] x86: also use debug_pagealloc_enabled() for free_init_pages Christian Borntraeger
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