Commit 170a5a7e authored by Jiang Liu's avatar Jiang Liu Committed by Linus Torvalds
Browse files

mm: make __free_pages_bootmem() only available at boot time



In order to simpilify management of totalram_pages and
zone->managed_pages, make __free_pages_bootmem() only available at boot
time.  With this change applied, __free_pages_bootmem() will only be
used by bootmem.c and nobootmem.c at boot time, so mark it as __init.
Other callers of __free_pages_bootmem() have been converted to use
free_reserved_page(), which handles totalram_pages and
zone->managed_pages in a safer way.

This patch also fix a bug in free_pagetable() for x86_64, which should
increase zone->managed_pages instead of zone->present_pages when freeing
reserved pages.

And now we have managed_pages_count_lock to protect totalram_pages and
zone->managed_pages, so remove the redundant ppb_lock lock in
put_page_bootmem().  This greatly simplifies the locking rules.
Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c3d5f5f0
......@@ -712,36 +712,22 @@ EXPORT_SYMBOL_GPL(arch_add_memory);
static void __meminit free_pagetable(struct page *page, int order)
{
struct zone *zone;
bool bootmem = false;
unsigned long magic;
unsigned int nr_pages = 1 << order;
/* bootmem page has reserved flag */
if (PageReserved(page)) {
__ClearPageReserved(page);
bootmem = true;
magic = (unsigned long)page->lru.next;
if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
while (nr_pages--)
put_page_bootmem(page++);
} else
__free_pages_bootmem(page, order);
while (nr_pages--)
free_reserved_page(page++);
} else
free_pages((unsigned long)page_address(page), order);
/*
* SECTION_INFO pages and MIX_SECTION_INFO pages
* are all allocated by bootmem.
*/
if (bootmem) {
zone = page_zone(page);
zone_span_writelock(zone);
zone->present_pages += nr_pages;
zone_span_writeunlock(zone);
totalram_pages += nr_pages;
}
}
static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
......
......@@ -101,12 +101,9 @@ void get_page_bootmem(unsigned long info, struct page *page,
atomic_inc(&page->_count);
}
/* reference to __meminit __free_pages_bootmem is valid
* so use __ref to tell modpost not to generate a warning */
void __ref put_page_bootmem(struct page *page)
void put_page_bootmem(struct page *page)
{
unsigned long type;
static DEFINE_MUTEX(ppb_lock);
type = (unsigned long) page->lru.next;
BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
......@@ -116,17 +113,8 @@ void __ref put_page_bootmem(struct page *page)
ClearPagePrivate(page);
set_page_private(page, 0);
INIT_LIST_HEAD(&page->lru);
/*
* Please refer to comment for __free_pages_bootmem()
* for why we serialize here.
*/
mutex_lock(&ppb_lock);
__free_pages_bootmem(page, 0);
mutex_unlock(&ppb_lock);
totalram_pages++;
free_reserved_page(page);
}
}
#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
......
......@@ -745,14 +745,7 @@ static void __free_pages_ok(struct page *page, unsigned int order)
local_irq_restore(flags);
}
/*
* Read access to zone->managed_pages is safe because it's unsigned long,
* but we still need to serialize writers. Currently all callers of
* __free_pages_bootmem() except put_page_bootmem() should only be used
* at boot time. So for shorter boot time, we shift the burden to
* put_page_bootmem() to serialize writers.
*/
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
void __init __free_pages_bootmem(struct page *page, unsigned int order)
{
unsigned int nr_pages = 1 << order;
unsigned int loop;
......
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