Add 'const' to static array that was missing it in its definition. Also,
'const' is added to ili9320_write_regs(), because it is called by
vgg2432a4 driver.
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add 'const' to static array that was missing it in its definition.
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Eric Miao <eric.y.miao@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add 'const' to static array that was missing it in its definition.
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Acked-by: Marek Vasut <marex@denx.de> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The mutex for accessing lp855x registers is used in case of the user-space
interaction. When the brightness is changed via sysfs, the mutex is
required. But the backlight class device already provides it. Thus, the
lp855x mutex is unnecessary.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> Cc: Thierry Reding <thierry.reding@avionic-design.de> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Bryan Wu <bryan.wu@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kim, Milo [Thu, 29 Nov 2012 03:18:25 +0000 (14:18 +1100)]
drivers/video/backlight/lp855x_bl.c: use generic PWM functions
The LP855x family devices support the PWM input for the backlight control.
Period of the PWM is configurable in the platform side. Platform
specific functions are unnecessary anymore because generic PWM functions
are used inside the driver.
(PWM input mode)
To set the brightness, new lp855x_pwm_ctrl() is used.
If a PWM device is not allocated, devm_pwm_get() is called.
The PWM consumer name is from the chip name such as 'lp8550' and 'lp8556'.
To get the brightness value, no additional handling is required.
Just the value of 'props.brightness' is returned.
If the PWM driver is not ready while initializing the LP855x driver, it's
OK. The PWM device can be retrieved later, when the brightness value is
changed.
Documentation is updated with an example.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> Cc: Thierry Reding <thierry.reding@avionic-design.de> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Bryan Wu <bryan.wu@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jingoo Han [Thu, 29 Nov 2012 03:18:25 +0000 (14:18 +1100)]
backlight: tosa: use devm_gpio_request_one
By using devm_gpio_request_one it is possible to set the direction and
initial value in one shot. Thus, using devm_gpio_request_one can make the
code simpler.
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Dmitry Baryshkov <dbaryshkov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jingoo Han [Thu, 29 Nov 2012 03:18:24 +0000 (14:18 +1100)]
backlight: lms283gf05: use devm_gpio_request_one
By using devm_gpio_request_one it is possible to set the direction
and initial value in one shot. Thus, using devm_gpio_request_one
can make the code simpler.
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Acked-by: Marek Vasut <marex@denx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jingoo Han [Thu, 29 Nov 2012 03:18:22 +0000 (14:18 +1100)]
backlight: locomolcd: fix checkpatch error and warning
This patch fixes the checkpatch error and warning as below:
WARNING: line over 80 characters
WARNING: space prohibited between function name and open parenthesis '('
ERROR: trailing statements should be on next line
Also, long comments are fixed for the preferred style and
unnecessary lines are removed.
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jingoo Han [Thu, 29 Nov 2012 03:18:21 +0000 (14:18 +1100)]
backlight: ili9320: fix checkpatch error and warning
This patch fixes the checkpatch error and warning as below:
WARNING: please, no space before tabs
WARNING: please, no spaces at the start of a line
WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
WARNING: braces {} are not necessary for single statement blocks
ERROR: code indent should use tabs where possible
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jingoo Han [Thu, 29 Nov 2012 03:18:20 +0000 (14:18 +1100)]
backlight: hp680_bl: fix checkpatch error and warning
This patch fixes the checkpatch error and warning as below:
WARNING: please, no space before tabs
WARNING: please, no spaces at the start of a line
ERROR: do not initialise statics to 0 or NULL
ERROR: code indent should use tabs where possible
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jingoo Han [Thu, 29 Nov 2012 03:18:19 +0000 (14:18 +1100)]
backlight: da903x_bl: use dev_get_drvdata() instead of platform_get_drvdata()
dev_get_drvdata() can be used instead of platform_get_drvdata()
to make the code smaller.
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Mike Rapoport <mike@compulab.co.il> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Andrew Cooks [Thu, 29 Nov 2012 03:18:18 +0000 (14:18 +1100)]
printk: boot_delay should only affect output
The boot_delay parameter affects all printk(), even if the log level
prevents visible output from the call. It results in delays greater than
the user intended without purpose.
This patch changes the behaviour of boot_delay to only delay output.
Signed-off-by: Andrew Cooks <acooks@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stephen Rothwell [Thu, 29 Nov 2012 03:18:17 +0000 (14:18 +1100)]
Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS
Make it easier for more architectures to select it and thus disable
drivers that use virt_to_bus().
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: H Hartley Sweeten <hartleys@visionengravers.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: James Hogan <james.hogan@imgtec.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Leach [Thu, 29 Nov 2012 03:18:15 +0000 (14:18 +1100)]
include/linux/init.h: use the stringify operator for the __define_initcall macro
Currently the __define_initcall() macro takes three arguments, fn, id and
level. The level argument is exactly the same as the id argument but
wrapped in quotes. To overcome this need to specify three arguments to
the __define_initcall macro, where one argument is the stringification of
another, we can just use the stringification macro instead.
Signed-off-by: Matthew Leach <matthew@mattleach.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wen Congyang [Thu, 29 Nov 2012 03:18:15 +0000 (14:18 +1100)]
Documentation/kernel-parameters.txt: update mem= option's spec according to its implementation
Current mem= implementation seems buggy because the specification and
implementation don't match. The current mem= has been working for many
years and it's not buggy - it works as expected. So we should update the
specification.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Rob Landley <rob@landley.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Xi Wang [Thu, 29 Nov 2012 03:18:14 +0000 (14:18 +1100)]
mm/dmapool.c: fix null dev in dma_pool_create()
A few drivers invoke dma_pool_create() with a null dev. Note that dev is
dereferenced in dev_to_node(dev), causing a null pointer dereference.
A long term solution is to disallow null dev. Once the drivers are fixed,
we can simplify the core code here. For now we add WARN_ON(!dev) to
notify the driver maintainers and avoid the null pointer dereference.
Signed-off-by: Xi Wang <xi.wang@gmail.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Xi Wang [Thu, 29 Nov 2012 03:18:14 +0000 (14:18 +1100)]
drivers/usb/gadget/amd5536udc.c: avoid calling dma_pool_create() with NULL dev
Calling dma_pool_create() with dev==NULL will oops on a NUMA machine.
Rather than changing dma_pool_create() we wish to disallow passing
dev==NULL. This requires fixing up the small number of drivers which are
passing in dev==NULL.
Use &dev->pdev->dev instead of NULL.
Signed-off-by: Xi Wang <xi.wang@gmail.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wanpeng Li [Thu, 29 Nov 2012 03:18:14 +0000 (14:18 +1100)]
mm/memblock: reduce overhead in binary search
When checking that the indicated address belongs to the memory region, the
memory regions are checked one by one through a binary search, which will
be time consuming.
If the indicated address isn't in the memory region, then we needn't do
the time-consuming search. Add a check on the indicated address for that
purpose.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Shaohua Li [Thu, 29 Nov 2012 03:18:13 +0000 (14:18 +1100)]
swap: add a simple detector for inappropriate swapin readahead
The swapin readahead does a blind readahead whether or not the swapin is
sequential. This is ok for harddisk because large reads have relatively
small costs and if the readahead pages are unneeded they can be reclaimed
easily. But for SSD devices large reads are more expensive than small
one. If readahead pages are unneeded, reading them in caused significant
overhead
This patch addes a simple random read detection similar to file mmap
readahead. If a random read is detected, swapin readahead will be
skipped. This improves a lot for a swap workload with random IO in a fast
SSD.
I run anonymous mmap write micro benchmark, which will triger swapin/swapout.
For both harddisk and SSD, the randwrite swap workload run time is reduced
significantly. Sequential write swap workload hasn't chanage.
Interestingly, the randwrite harddisk test is improved too. This might be
because swapin readahead needs to allocate extra memory, which further
tights memory pressure, so more swapout/swapin.
Signed-off-by: Shaohua Li <shli@fusionio.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Michal Hocko [Thu, 29 Nov 2012 03:18:13 +0000 (14:18 +1100)]
drop_caches: add some documentation and info message
I would like to resurrect Dave's patch. The last time it was posted was
here https://lkml.org/lkml/2010/9/16/250 and there didn't seem to be any
strong opposition.
Kosaki was worried about possible excessive logging when somebody drops
caches too often (but then he claimed he didn't have a strong opinion on
that) but I would say opposite. If somebody does that then I would really
like to know that from the log when supporting a system because it almost
for sure means that there is something fishy going on. It is also worth
mentioning that only root can write drop caches so this is not an flooding
attack vector.
I am bringing that up again because this can be really helpful when
chasing strange performance issues which (surprise surprise) turn out to
be related to artificially dropped caches done because the admin thinks
this would help...
I have just refreshed the original patch on top of the current mm tree
but I could live with KERN_INFO as well if people think that KERN_NOTICE
is too hysterical.
: From: Dave Hansen <dave@linux.vnet.ibm.com>
: Date: Fri, 12 Oct 2012 14:30:54 +0200
:
: There is plenty of anecdotal evidence and a load of blog posts
: suggesting that using "drop_caches" periodically keeps your system
: running in "tip top shape". Perhaps adding some kernel
: documentation will increase the amount of accurate data on its use.
:
: If we are not shrinking caches effectively, then we have real bugs.
: Using drop_caches will simply mask the bugs and make them harder
: to find, but certainly does not fix them, nor is it an appropriate
: "workaround" to limit the size of the caches.
:
: It's a great debugging tool, and is really handy for doing things
: like repeatable benchmark runs. So, add a bit more documentation
: about it, and add a little KERN_NOTICE. It should help developers
: who are chasing down reclaim-related bugs.
[mhocko@suse.cz: refreshed to current -mm tree] Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jiang Liu [Thu, 29 Nov 2012 03:18:12 +0000 (14:18 +1100)]
mm: provide more accurate estimation of pages occupied by memmap
If SPARSEMEM is enabled, it won't build page structures for non-existing
pages (holes) within a zone, so provide a more accurate estimation of
pages occupied by memmap if there are bigger holes within the zone.
And pages for highmem zones' memmap will be allocated from lowmem, so
charge nr_kernel_pages for that.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Maciej Rutecki <maciej.rutecki@gmail.com> Cc: 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: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Robert Jarzmik [Thu, 29 Nov 2012 03:18:11 +0000 (14:18 +1100)]
mm: trace filemap add and del
Use the events API to trace filemap loading and unloading of file pieces
into the page cache.
This patch aims at tracing the eviction reload cycle of executable and
shared libraries pages in a memory constrained environment.
The typical usage is to spot a specific device and inode (for example
/lib/libc.so) to see the eviction cycles, and find out if frequently used
code is rather spread across many pages (bad) or coallesced (good).
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Cc: Dave Chinner <david@fromorbit.com> Cc: Hugh Dickins <hughd@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/2012/11/5/866
https://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:
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.
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> Cc: 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>
David Rientjes [Thu, 29 Nov 2012 03:18:10 +0000 (14:18 +1100)]
mm, oom: remove statically defined arch functions of same name
out_of_memory() is a globally defined function to call the oom killer.
x86, sh, and powerpc all use a function of the same name within file scope
in their respective fault.c unnecessarily. Inline the functions into the
pagefault handlers to clean the code up.
Signed-off-by: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Thu, 29 Nov 2012 03:18:09 +0000 (14:18 +1100)]
mm, oom: remove redundant sleep in pagefault oom handler
out_of_memory() will already cause current to schedule if it has not been
killed, so doing it again in pagefault_out_of_memory() is redundant.
Remove it.
Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Thu, 29 Nov 2012 03:18:09 +0000 (14:18 +1100)]
mm, oom: cleanup pagefault oom handler
To lock the entire system from parallel oom killing, it's possible to pass
in a zonelist with all zones rather than using for_each_populated_zone()
for the iteration. This obsoletes try_set_system_oom() and
clear_system_oom() so that they can be removed.
Signed-off-by: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lai Jiangshan [Thu, 29 Nov 2012 03:18:08 +0000 (14:18 +1100)]
numa: add CONFIG_MOVABLE_NODE for movable-dedicated node
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
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Tested-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Thu, 29 Nov 2012 03:18:08 +0000 (14:18 +1100)]
mm, memcg: avoid unnecessary function call when memcg is disabled
While profiling numa/core v16 with cgroup_disable=memory on the command
line, I noticed mem_cgroup_count_vm_event() still showed up as high as
0.60% in perftop.
This occurs because the function is called extremely often even when memcg
is disabled.
To fix this, inline the check for mem_cgroup_disabled() so we avoid the
unnecessary function call if memcg is disabled.
Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Glauber Costa <glommer@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Joonsoo Kim [Thu, 29 Nov 2012 03:18:07 +0000 (14:18 +1100)]
mm: WARN_ON_ONCE if f_op->mmap() change vma's start address
During reviewing the source code, I found a comment which mention that
after f_op->mmap(), vma's start address can be changed. I didn't verify
that it is really possible, because there are so many f_op->mmap()
implementation. But if there are some mmap() which change vma's start
address, it is possible error situation, because we already prepare prev
vma, rb_link and rb_parent and these are related to original address.
So add WARN_ON_ONCE for finding that this situtation really happens.
Signed-off-by: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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 <laijs@cn.fujitsu.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Lin Feng <linfeng@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Marek Szyprowski [Thu, 29 Nov 2012 03:18:02 +0000 (14:18 +1100)]
mm: use migrate_prep() instead of migrate_prep_local()
__alloc_contig_migrate_range() should use all possible ways to get all the
pages migrated from the given memory range, so pruning per-cpu lru lists
for all CPUs is required, regadless the cost of such operation. Otherwise
some pages which got stuck at per-cpu lru list might get missed by
migration procedure causing the contiguous allocation to fail.
Reported-by: SeongHwan Yoon <sunghwan.yun@samsung.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
thp, vmstat: implement HZP_ALLOC and HZP_ALLOC_FAILED events
hzp_alloc is incremented every time a huge zero page is successfully
allocated. It includes allocations which where dropped due
race with other allocation. Note, it doesn't count every map
of the huge zero page, only its allocation.
hzp_alloc_failed is incremented if kernel fails to allocate huge zero
page and falls back to using small pages.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
thp, vmstat: implement HZP_ALLOC and HZP_ALLOC_FAILED events
hzp_alloc is incremented every time a huge zero page is successfully
allocated. It includes allocations which where dropped due
race with other allocation. Note, it doesn't count every map
of the huge zero page, only its allocation.
hzp_alloc_failed is incremented if kernel fails to allocate huge zero
page and falls back to using small pages.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
H. Peter Anvin doesn't like huge zero page which sticks in memory forever
after the first allocation. Here's implementation of lockless refcounting
for huge zero page.
We have two basic primitives: {get,put}_huge_zero_page(). They
manipulate reference counter.
If counter is 0, get_huge_zero_page() allocates a new huge page and takes
two references: one for caller and one for shrinker. We free the page
only in shrinker callback if counter is 1 (only shrinker has the
reference).
put_huge_zero_page() only decrements counter. Counter is never zero in
put_huge_zero_page() since shrinker holds on reference.
Freeing huge zero page in shrinker callback helps to avoid frequent
allocate-free.
Refcounting has cost. On 4 socket machine I observe ~1% slowdown on
parallel (40 processes) read page faulting comparing to lazy huge page
allocation. I think it's pretty reasonable for synthetic benchmark.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
On write access to huge zero page we alloc a new huge page and clear it.
If ENOMEM, graceful fallback: we create a new pmd table and set pte
around fault address to newly allocated normal (4k) page. All other ptes
in the pmd set to normal zero page.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
On write access to huge zero page we alloc a new huge page and clear it.
If ENOMEM, graceful fallback: we create a new pmd table and set pte around
fault address to newly allocated normal (4k) page. All other ptes in the
pmd set to normal zero page.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Thu, 29 Nov 2012 03:17:35 +0000 (14:17 +1100)]
thp: copy_huge_pmd(): copy huge zero page v6 fix
Fix comment
Signed-off-by: David Rientjes <rientjes@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / karo-tx-linux.git / log