Use "pgdat_end_pfn()" instead of "pgdat->node_start_pfn +
pgdat->node_spanned_pages". Simplify the code, no functional change.
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently free_all_bootmem_core ignores that node_min_pfn may be not
multiple of BITS_PER_LONG. Eg commit 6dccdcbe2c ("mm: bootmem: fix
checking the bitmap when finally freeing bootmem") shifts vec by lower
bits of start instead of lower bits of idx. Also
if (IS_ALIGNED(start, BITS_PER_LONG) && vec == ~0UL)
assumes that vec bit 0 corresponds to start pfn, which is only true when
node_min_pfn is a multiple of BITS_PER_LONG. Also loop in the else
clause can double-free pages (e.g. with node_min_pfn == start == 1,
map[0] == ~0 on 32-bit machine page 32 will be double-freed).
This bug causes the following message during xtensa kernel boot:
bootmem::free_all_bootmem_core nid=0 start=1 end=8000
BUG: Bad page state in process swapper pfn:00001
page:d04bd020 count:0 mapcount:-127 mapping: (null) index:0x2
page flags: 0x0()
Call Trace:
bad_page+0x8c/0x9c
free_pages_prepare+0x5e/0x88
free_hot_cold_page+0xc/0xa0
__free_pages+0x24/0x38
__free_pages_bootmem+0x54/0x56
free_all_bootmem_core$part$11+0xeb/0x138
free_all_bootmem+0x46/0x58
mem_init+0x25/0xa4
start_kernel+0x11e/0x25c
should_never_return+0x0/0x3be7
The fix is the following:
- always align vec so that its bit 0 corresponds to start
- provide BITS_PER_LONG bits in vec, if those bits are available in the
map
- don't free pages past next start position in the else clause.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Prasad Koya <prasad.koya@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently a zone's present_pages is calcuated as below, which is
inaccurate and may cause trouble to memory hotplug.
spanned_pages - absent_pages - memmap_pages - dma_reserve.
During fixing bugs caused by inaccurate zone->present_pages, we found
zone->present_pages has been abused. The field zone->present_pages may
have different meanings in different contexts:
1) pages existing in a zone.
2) pages managed by the buddy system.
For more discussions about the issue, please refer to:
http://lkml.org/lkml/2012/11/5/866https://patchwork.kernel.org/patch/1346751/
This patchset tries to introduce a new field named "managed_pages" to
struct zone, which counts "pages managed by the buddy system". And revert
zone->present_pages to count "physical pages existing in a zone", which
also keep in consistence with pgdat->node_present_pages.
We will set an initial value for zone->managed_pages in function
free_area_init_core() and will adjust it later if the initial value is
inaccurate.
For DMA/normal zones, the initial value is set to:
(spanned_pages - absent_pages - memmap_pages - dma_reserve)
Later zone->managed_pages will be adjusted to the accurate value when the
bootmem allocator frees all free pages to the buddy system in function
free_all_bootmem_node() and free_all_bootmem().
The bootmem allocator doesn't touch highmem pages, so highmem zones'
managed_pages is set to the accurate value "spanned_pages - absent_pages"
in function free_area_init_core() and won't be updated anymore.
This patch also adds a new field "managed_pages" to /proc/zoneinfo
and sysrq showmem.
[akpm@linux-foundation.org: small comment tweaks]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Cc: "Rafael J . Wysocki" <rjw@sisk.pl>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is strange that alloc_bootmem() returns a virtual address and
free_bootmem() requires a physical address. Anyway, free_bootmem()'s
first parameter should be physical address.
There are some call sites for free_bootmem() with virtual address. So fix
them.
[akpm@linux-foundation.org: improve free_bootmem() and free_bootmem_pate() documentation]
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert commit 7f1290f2f2 ("mm: fix-up zone present pages")
That patch tried to fix a issue when calculating zone->present_pages,
but it caused a regression on 32bit systems with HIGHMEM. With that
change, reset_zone_present_pages() resets all zone->present_pages to
zero, and fixup_zone_present_pages() is called to recalculate
zone->present_pages when the boot allocator frees core memory pages into
buddy allocator. Because highmem pages are not freed by bootmem
allocator, all highmem zones' present_pages becomes zero.
Various options for improving the situation are being discussed but for
now, let's return to the 3.6 code.
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I think zone->present_pages indicates pages that buddy system can management,
it should be:
zone->present_pages = spanned pages - absent pages - bootmem pages,
but is now:
zone->present_pages = spanned pages - absent pages - memmap pages.
spanned pages: total size, including holes.
absent pages: holes.
bootmem pages: pages used in system boot, managed by bootmem allocator.
memmap pages: pages used by page structs.
This may cause zone->present_pages less than it should be. For example,
numa node 1 has ZONE_NORMAL and ZONE_MOVABLE, it's memmap and other
bootmem will be allocated from ZONE_MOVABLE, so ZONE_NORMAL's
present_pages should be spanned pages - absent pages, but now it also
minus memmap pages(free_area_init_core), which are actually allocated from
ZONE_MOVABLE. When offlining all memory of a zone, this will cause
zone->present_pages less than 0, because present_pages is unsigned long
type, it is actually a very large integer, it indirectly caused
zone->watermark[WMARK_MIN] becomes a large
integer(setup_per_zone_wmarks()), than cause totalreserve_pages become a
large integer(calculate_totalreserve_pages()), and finally cause memory
allocating failure when fork process(__vm_enough_memory()).
[root@localhost ~]# dmesg
-bash: fork: Cannot allocate memory
I think the bug described in
http://marc.info/?l=linux-mm&m=134502182714186&w=2
is also caused by wrong zone present pages.
This patch intends to fix-up zone->present_pages when memory are freed to
buddy system on x86_64 and IA64 platforms.
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Reported-by: Petr Tesarik <ptesarik@suse.cz>
Tested-by: Petr Tesarik <ptesarik@suse.cz>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In reaction to commit 99ab7b1944 ("mm: sparse: fix usemap allocation
above node descriptor section") Johannes said:
| while backporting the below patch, I realised that your fix busted
| f5bf18fa22 again. The problem was not a panicking version on
| allocation failure but when the usemap size was too large such that
| goal + size > limit triggers the BUG_ON in the bootmem allocator. So
| we need a version that passes limit ONLY if the usemap is smaller than
| the section.
after checking the code, the name of ___alloc_bootmem_node_nopanic()
does not reflect the fact.
Make bootmem really not panic.
Hope will kill bootmem sooner.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org> [3.3.x, 3.4.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit f5bf18fa22 ("bootmem/sparsemem: remove limit constraint
in alloc_bootmem_section"), usemap allocations may easily be placed
outside the optimal section that holds the node descriptor, even if
there is space available in that section. This results in unnecessary
hotplug dependencies that need to have the node unplugged before the
section holding the usemap.
The reason is that the bootmem allocator doesn't guarantee a linear
search starting from the passed allocation goal but may start out at a
much higher address absent an upper limit.
Fix this by trying the allocation with the limit at the section end,
then retry without if that fails. This keeps the fix from f5bf18fa22
of not panicking if the allocation does not fit in the section, but
still makes sure to try to stay within the section at first.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org> [3.3.x, 3.4.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The objects of "struct bootmem_data_t" are linked together to form
double-linked list sequentially based on its minimal page frame number.
The current implementation implicitly supports the following cases,
which means the inserting point for current bootmem data depends on how
"list_for_each" works. That makes the code a little hard to read.
Besides, "list_for_each" and "list_entry" can be replaced with
"list_for_each_entry".
- The linked list is empty.
- There has no entry in the linked list, whose minimal page
frame number is bigger than current one.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alloc_bootmem_section() derives allocation area constraints from the
specified sparsemem section. This is a bit specific for a generic memory
allocator like bootmem, though, so move it over to sparsemem.
As __alloc_bootmem_node_nopanic() already retries failed allocations with
relaxed area constraints, the fallback code in sparsemem.c can be removed
and the code becomes a bit more compact overall.
[akpm@linux-foundation.org: fix build]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While the panicking node-specific allocation function tries to satisfy
node+goal, goal, node, anywhere, the non-panicking function still does
node+goal, goal, anywhere.
Make it simpler: define the panicking version in terms of the
non-panicking one, like the node-agnostic interface, so they always behave
the same way apart from how to deal with allocation failure.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matching the desired goal to the right node is one thing, dropping the
goal when it can not be satisfied is another. Split this into separate
functions so that subsequent patches can use the node-finding but drop and
handle the goal fallback on their own terms.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
