linux-stable.git/include/linux/nodemask.h, branch v4.9.321

nodemask: Fix return values to be unsigned

2022-06-14T14:52:40+00:00

[ Upstream commit 0dfe54071d7c828a02917b595456bfde1afdddc9 ]

The nodemask routines had mixed return values that provided potentially
signed return values that could never happen. This was leading to the
compiler getting confusing about the range of possible return values
(it was thinking things could be negative where they could not be). Fix
all the nodemask routines that should be returning unsigned
(or bool) values. Silences:

 mm/swapfile.c: In function ‘setup_swap_info’:
 mm/swapfile.c:2291:47: error: array subscript -1 is below array bounds of ‘struct plist_node[]’ [-Werror=array-bounds]
  2291 |                                 p->avail_lists[i].prio = 1;
       |                                 ~~~~~~~~~~~~~~^~~
 In file included from mm/swapfile.c:16:
 ./include/linux/swap.h:292:27: note: while referencing ‘avail_lists’
   292 |         struct plist_node avail_lists[]; /*
       |                           ^~~~~~~~~~~

Reported-by: Christophe de Dinechin 
Link: https://lore.kernel.org/lkml/20220414150855.2407137-3-dinechin@redhat.com/
Cc: Alexey Dobriyan 
Cc: Yury Norov 
Cc: Andy Shevchenko 
Cc: Rasmus Villemoes 
Cc: Andrew Morton 
Cc: Zhen Lei 
Signed-off-by: Kees Cook 
Signed-off-by: Yury Norov 
Signed-off-by: Sasha Levin

nodemask.h: fix compilation error with GCC12

2022-06-14T14:52:36+00:00

commit 37462a920392cb86541650a6f4121155f11f1199 upstream.

With gcc version 12.0.1 20220401 (Red Hat 12.0.1-0), building with
defconfig results in the following compilation error:

|   CC      mm/swapfile.o
| mm/swapfile.c: In function `setup_swap_info':
| mm/swapfile.c:2291:47: error: array subscript -1 is below array bounds
|  of `struct plist_node[]' [-Werror=array-bounds]
|  2291 |                                 p->avail_lists[i].prio = 1;
|       |                                 ~~~~~~~~~~~~~~^~~
| In file included from mm/swapfile.c:16:
| ./include/linux/swap.h:292:27: note: while referencing `avail_lists'
|   292 |         struct plist_node avail_lists[]; /*
|       |                           ^~~~~~~~~~~

This is due to the compiler detecting that the mask in
node_states[__state] could theoretically be zero, which would lead to
first_node() returning -1 through find_first_bit.

I believe that the warning/error is legitimate.  I first tried adding a
test to check that the node mask is not emtpy, since a similar test exists
in the case where MAX_NUMNODES == 1.

However, adding the if statement causes other warnings to appear in
for_each_cpu_node_but, because it introduces a dangling else ambiguity.
And unfortunately, GCC is not smart enough to detect that the added test
makes the case where (node) == -1 impossible, so it still complains with
the same message.

This is why I settled on replacing that with a harmless, but relatively
useless (node) >= 0 test.  Based on the warning for the dangling else, I
also decided to fix the case where MAX_NUMNODES == 1 by moving the
condition inside the for loop.  It will still only be tested once.  This
ensures that the meaning of an else following for_each_node_mask or
derivatives would not silently have a different meaning depending on the
configuration.

Link: https://lkml.kernel.org/r/20220414150855.2407137-3-dinechin@redhat.com
Signed-off-by: Christophe de Dinechin 
Signed-off-by: Christophe de Dinechin 
Reviewed-by: Andrew Morton 
Cc: Ben Segall 
Cc: "Michael S. Tsirkin" 
Cc: Steven Rostedt 
Cc: Ingo Molnar 
Cc: Mel Gorman 
Cc: Dietmar Eggemann 
Cc: Vincent Guittot 
Cc: Paolo Bonzini 
Cc: Daniel Bristot de Oliveira 
Cc: Jason Wang 
Cc: Zhen Lei 
Cc: Juri Lelli 
Cc: Peter Zijlstra 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

include/linux/nodemask.h: create next_node_in() helper

2016-05-20T02:12:14+00:00

Lots of code does

	node = next_node(node, XXX);
	if (node == MAX_NUMNODES)
		node = first_node(XXX);

so create next_node_in() to do this and use it in various places.

[mhocko@suse.com: use next_node_in() helper]
Acked-by: Vlastimil Babka 
Acked-by: Michal Hocko 
Signed-off-by: Michal Hocko 
Cc: Xishi Qiu 
Cc: Joonsoo Kim 
Cc: David Rientjes 
Cc: Naoya Horiguchi 
Cc: Laura Abbott 
Cc: Hui Zhu 
Cc: Wang Xiaoqiang 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

bitmap, cpumask, nodemask: remove dedicated formatting functions

2015-02-14T05:21:39+00:00

Now that all bitmap formatting usages have been converted to
'%*pb[l]', the separate formatting functions are unnecessary.  The
following functions are removed.

* bitmap_scn[list]printf()
* cpumask_scnprintf(), cpulist_scnprintf()
* [__]nodemask_scnprintf(), [__]nodelist_scnprintf()
* seq_bitmap[_list](), seq_cpumask[_list](), seq_nodemask[_list]()
* seq_buf_bitmask()

Signed-off-by: Tejun Heo 
Cc: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cpumask, nodemask: implement cpumask/nodemask_pr_args()

2015-02-14T05:21:36+00:00

printf family of functions can now format bitmaps using '%*pb[l]' and
all cpumask and nodemask formatting will be converted to use it.  To
ease printing these masks with '%*pb[l]' which require two params -
the number of bits and the actual bitmap, this patch implement
cpumask_pr_args() and nodemask_pr_args() which can be used to provide
arguments for '%*pb[l]'

Signed-off-by: Tejun Heo 
Cc: Rusty Russell 
Cc: "David S. Miller" 
Cc: "James E.J. Bottomley" 
Cc: "John W. Linville" 
Cc: "Paul E. McKenney" 
Cc: Benjamin Herrenschmidt 
Cc: Chris Metcalf 
Cc: Chris Zankel 
Cc: Christoph Lameter 
Cc: Dmitry Torokhov 
Cc: Fenghua Yu 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: Li Zefan 
Cc: Max Filippov 
Cc: Mike Travis 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: Russell King 
Cc: Steffen Klassert 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

linux/nodemask.h: update bitmap wrappers to take unsigned int

2015-02-13T02:54:14+00:00

Since the various bitmap_* functions now take an unsigned int as nbits
parameter, it makes sense to also update the various wrappers.

Signed-off-by: Rasmus Villemoes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, oom: ensure memoryless node zonelist always includes zones

2014-08-07T01:01:21+00:00

With memoryless node support being worked on, it's possible that for
optimizations that a node may not have a non-NULL zonelist.  When
CONFIG_NUMA is enabled and node 0 is memoryless, this means the zonelist
for first_online_node may become NULL.

The oom killer requires a zonelist that includes all memory zones for
the sysrq trigger and pagefault out of memory handler.

Ensure that a non-NULL zonelist is always passed to the oom killer.

[akpm@linux-foundation.org: fix non-numa build]
Signed-off-by: David Rientjes 
Cc: "Kirill A. Shutemov" 
Cc: Johannes Weiner 
Cc: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

numa: Mark __node_set() as __always_inline

2013-07-25T19:54:01+00:00

It is posible for some compilers to decide that __node_set() does
not need to be made turned into an inline function.  When the
compiler does this on an __init function calling it on
__initdata we get a section mismatch warning now.  Use
__always_inline to ensure that we will be inlined.

Reported-by: Paul Bolle 
Cc: Jianpeng Ma 
Cc: Rusty Russell 
Cc: Lai Jiangshan 
Cc: Yasuaki Ishimatsu 
Cc: Wen Congyang 
Cc: Jiang Liu 
Cc: KOSAKI Motohiro 
Cc: Minchan Kim 
Cc: Mel Gorman 
Cc: David Rientjes 
Cc: Yinghai Lu 
Cc: Greg KH 
Signed-off-by: Tom Rini 
Link: http://lkml.kernel.org/r/1374776770-32361-1-git-send-email-trini@ti.com
Signed-off-by: Ingo Molnar

numa: add CONFIG_MOVABLE_NODE for movable-dedicated node

2012-12-13T01:38:34+00:00

We need a node which only contains movable memory.  This feature is very
important for node hotplug.  If a node has normal/highmem, the memory may
be used by the kernel and can't be offlined.  If the node only contains
movable memory, we can offline the memory and the node.

All are prepared, we can actually introduce N_MEMORY.
add CONFIG_MOVABLE_NODE make we can use it for movable-dedicated node

[akpm@linux-foundation.org: fix Kconfig text]
Signed-off-by: Lai Jiangshan 
Tested-by: Yasuaki Ishimatsu 
Signed-off-by: Wen Congyang 
Cc: Jiang Liu 
Cc: KOSAKI Motohiro 
Cc: Minchan Kim 
Cc: Mel Gorman 
Cc: David Rientjes 
Cc: Yinghai Lu 
Cc: Rusty Russell 
Cc: Greg KH 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: node_states: introduce N_MEMORY

2012-12-13T01:38:32+00:00

We have N_NORMAL_MEMORY for standing for the nodes that have normal memory
with zone_type <= ZONE_NORMAL.

And we have N_HIGH_MEMORY for standing for the nodes that have normal or
high memory.

But we don't have any word to stand for the nodes that have *any* memory.

And we have N_CPU but without N_MEMORY.

Current code reuse the N_HIGH_MEMORY for this purpose because any node
which has memory must have high memory or normal memory currently.

A)	But this reusing is bad for *readability*. Because the name
	N_HIGH_MEMORY just stands for high or normal:

A.example 1)
	mem_cgroup_nr_lru_pages():
		for_each_node_state(nid, N_HIGH_MEMORY)

	The user will be confused(why this function just counts for high or
	normal memory node? does it counts for ZONE_MOVABLE's lru pages?)
	until someone else tell them N_HIGH_MEMORY is reused to stand for
	nodes that have any memory.

A.cont) If we introduce N_MEMORY, we can reduce this confusing
	AND make the code more clearly:

A.example 2) mm/page_cgroup.c use N_HIGH_MEMORY twice:

	One is in page_cgroup_init(void):
		for_each_node_state(nid, N_HIGH_MEMORY) {

	It means if the node have memory, we will allocate page_cgroup map for
	the node. We should use N_MEMORY instead here to gaim more clearly.

	The second using is in alloc_page_cgroup():
		if (node_state(nid, N_HIGH_MEMORY))
			addr = vzalloc_node(size, nid);

	It means if the node has high or normal memory that can be allocated
	from kernel. We should keep N_HIGH_MEMORY here, and it will be better
	if the "any memory" semantic of N_HIGH_MEMORY is removed.

B)	This reusing is out-dated if we introduce MOVABLE-dedicated node.
	The MOVABLE-dedicated node should not appear in
	node_stats[N_HIGH_MEMORY] nor node_stats[N_NORMAL_MEMORY],
	because MOVABLE-dedicated node has no high or normal memory.

	In x86_64, N_HIGH_MEMORY=N_NORMAL_MEMORY, if a MOVABLE-dedicated node
	is in node_stats[N_HIGH_MEMORY], it is also means it is in
	node_stats[N_NORMAL_MEMORY], it causes SLUB wrong.

	The slub uses
		for_each_node_state(nid, N_NORMAL_MEMORY)
	and creates kmem_cache_node for MOVABLE-dedicated node and cause problem.

In one word, we need a N_MEMORY.  We just intrude it as an alias to
N_HIGH_MEMORY and fix all im-proper usages of N_HIGH_MEMORY in late
patches.

Signed-off-by: Lai Jiangshan 
Acked-by: Christoph Lameter 
Acked-by: Hillf Danton 
Signed-off-by: Wen Congyang 
Cc: Lin Feng 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds