From: Jiang Liu <jiang.liu@huawei.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mgorman@suse.de>, Tony Luck <tony.luck@intel.com>,
Yinghai Lu <yinghai@kernel.org>
Cc: Xishi Qiu <qiuxishi@huawei.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
David Rientjes <rientjes@google.com>,
Minchan Kim <minchan@kernel.org>,
Keping Chen <chenkeping@huawei.com>,
linux-mm@kvack.org, stable@vger.kernel.org,
linux-kernel@vger.kernel.org, Jiang Liu <liuj97@gmail.com>
Subject: [PATCH] mm: setup pageblock_order before it's used by sparse
Date: Sat, 30 Jun 2012 17:07:54 +0800 [thread overview]
Message-ID: <1341047274-5616-1-git-send-email-jiang.liu@huawei.com> (raw)
From: Xishi Qiu <qiuxishi@huawei.com>
On architectures with CONFIG_HUGETLB_PAGE_SIZE_VARIABLE set, such as Itanium,
pageblock_order is a variable with default value of 0. It's set to the right
value by set_pageblock_order() in function free_area_init_core().
But pageblock_order may be used by sparse_init() before free_area_init_core()
is called along path:
sparse_init()
->sparse_early_usemaps_alloc_node()
->usemap_size()
->SECTION_BLOCKFLAGS_BITS
->((1UL << (PFN_SECTION_SHIFT - pageblock_order)) *
NR_PAGEBLOCK_BITS)
The uninitialized pageblock_size will cause memory wasting because usemap_size()
returns a much bigger value then it's really needed.
For example, on an Itanium platform,
sparse_init() pageblock_order=0 usemap_size=24576
free_area_init_core() before pageblock_order=0, usemap_size=24576
free_area_init_core() after pageblock_order=12, usemap_size=8
That means 24K memory has been wasted for each section, so fix it by calling
set_pageblock_order() from sparse_init().
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
---
mm/internal.h | 2 ++
mm/page_alloc.c | 4 ++--
mm/sparse.c | 3 +++
3 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index 2ba87fb..8052379 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -347,3 +347,5 @@ extern u32 hwpoison_filter_enable;
extern unsigned long vm_mmap_pgoff(struct file *, unsigned long,
unsigned long, unsigned long,
unsigned long, unsigned long);
+
+extern void set_pageblock_order(void);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4403009..f38509b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4301,7 +4301,7 @@ static inline void setup_usemap(struct pglist_data *pgdat,
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
-static inline void __init set_pageblock_order(void)
+void __init set_pageblock_order(void)
{
unsigned int order;
@@ -4329,7 +4329,7 @@ static inline void __init set_pageblock_order(void)
* include/linux/pageblock-flags.h for the values of pageblock_order based on
* the kernel config
*/
-static inline void set_pageblock_order(void)
+void __init set_pageblock_order(void)
{
}
diff --git a/mm/sparse.c b/mm/sparse.c
index fca2ab5..3a3af73 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -485,6 +485,9 @@ void __init sparse_init(void)
struct page **map_map;
#endif
+ /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
+ set_pageblock_order();
+
/*
* map is using big page (aka 2M in x86 64 bit)
* usemap is less one page (aka 24 bytes)
--
1.7.1
--
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next reply other threads:[~2012-06-30 9:10 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-30 9:07 Jiang Liu [this message]
2012-06-30 20:15 ` [PATCH] mm: setup pageblock_order before it's used by sparse Yinghai Lu
2012-07-02 2:01 ` Jiang Liu
2012-07-02 20:43 ` Yinghai Lu
2012-07-03 2:54 ` Jiang Liu
2012-07-03 3:25 ` Yinghai Lu
2012-07-03 3:29 ` Jiang Liu
2012-07-18 7:17 ` Benjamin Herrenschmidt
2012-07-18 7:15 ` Benjamin Herrenschmidt
2012-06-30 20:46 ` Greg KH
2012-07-02 12:41 ` Mel Gorman
2012-07-03 21:07 ` Andrew Morton
2012-07-04 1:40 ` Jiang Liu
2012-07-04 9:20 ` Mel Gorman
2012-07-06 1:00 ` Yinghai Lu
2012-07-06 1:24 ` Benjamin Herrenschmidt
2012-07-17 9:31 ` Jiang Liu
2012-07-18 7:01 ` Benjamin Herrenschmidt
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