Mel Gorman d0164adc89 mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd ... __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2015-11-06 17:50:42 -08:00
..
ABI	There is a nice new document from Neil on how pathname lookups work and	2015-11-05 15:59:24 -08:00
accounting
acpi	mfd: core: redo ACPI matching of the children devices	2015-10-26 15:25:53 +01:00
aoe
arm	arm64 updates for 4.4:	2015-11-04 14:47:13 -08:00
arm64	arm64 updates for 4.4:	2015-11-04 14:47:13 -08:00
auxdisplay
backlight
blackfin	Docs: blackfin: Use new switch macro SAMPLE_IRQ_TIMER instead of IRQ_TIMER5	2015-05-07 09:35:14 -06:00
block	block: add an API for Persistent Reservations	2015-10-21 14:46:56 -06:00
blockdev	zram: update documentation	2015-09-24 15:39:42 -06:00
bus-devices
cdrom
cgroups	There is a nice new document from Neil on how pathname lookups work and	2015-11-05 15:59:24 -08:00
cma	cma: debug: document new debugfs interface	2015-04-14 16:49:00 -07:00
connector
console
cpu-freq	cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event	2015-09-01 15:50:38 +02:00
cpuidle
cris
crypto	KEYS: Merge the type-specific data with the payload data	2015-10-21 15:18:36 +01:00
development-process
device-mapper	- Revert a dm-multipath change that caused a regression for unprivledged	2015-11-04 21:19:53 -08:00
devicetree	- New Device Support	2015-11-06 10:53:48 -08:00
dmaengine	Documentation: dmaengine: Add DMA_CTRL_REUSE documentation	2015-08-17 13:46:22 +05:30
DocBook	There is a nice new document from Neil on how pathname lookups work and	2015-11-05 15:59:24 -08:00
driver-model	driver-core: platform: Provide helpers for multi-driver modules	2015-10-05 05:02:40 +01:00
dvb
early-userspace
EDID
extcon
fault-injection	futex: Fault/error injection capabilities	2015-07-20 11:45:45 +02:00
fb	Documentation/fb: add documentation for sm712fb	2015-08-07 15:05:01 -07:00
features	arm64 updates for 4.4:	2015-11-04 14:47:13 -08:00
filesystems	Merge branch 'akpm' (patches from Andrew)	2015-11-05 23:10:54 -08:00
firmware_class
fmc
fpga	usage documentation for FPGA manager core	2015-10-07 18:07:20 +01:00
frv
gpio	There is a nice new document from Neil on how pathname lookups work and	2015-11-05 15:59:24 -08:00
hid	HID: sensor: Update document for custom sensor	2015-04-10 22:22:56 +02:00
hwmon	hwmon: (lm75) Add support for TMP75C	2015-10-14 07:57:14 -07:00
i2c	i2c: support 10 bit and slave addresses in sysfs 'new_device'	2015-08-24 14:05:15 +02:00
ia64	virtual: Documentation: simplify and generalize paravirt_ops.txt	2015-02-13 17:15:44 +10:30
ide
infiniband	IB/hfi1: add driver files	2015-08-28 22:59:36 -04:00
input	Input: fix typo in MT documentation	2015-09-19 11:39:02 -07:00
ioctl	char/misc drivers for 4.4-rc1	2015-11-04 22:15:15 -08:00
isdn
ja_JP	Doc: ja_JP: Fix typo in HOWTO	2015-06-08 16:43:09 -06:00
kbuild	modsign: Allow password to be specified for signing key	2015-08-07 16:26:14 +01:00
kdump	kernel: add panic_on_warn	2014-12-10 17:41:10 -08:00
ko_KR
laptops	Move freefall program from Documentation/ to tools/	2015-06-08 16:42:07 -06:00
leds	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds	2015-07-01 19:09:11 -07:00
locking	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-11-03 16:10:43 -08:00
m68k
memory-devices
metag
mic	misc: mic: Update MIC host daemon with COSM changes	2015-10-04 12:54:54 +01:00
mips
misc-devices	Doc:misc-devices: Fix typo in Documentation/misc-devices	2015-09-18 10:04:24 -06:00
mmc	mmc: core: Remove MMC_CLKGATE	2015-10-26 16:00:09 +01:00
mn10300
mtd
namespaces
netlabel
networking	There is a nice new document from Neil on how pathname lookups work and	2015-11-05 15:59:24 -08:00
nfc	NFC: Fix typo in nfc-hci.txt	2015-06-08 23:15:45 +02:00
nios2	Documentation: Add documentation for Nios2 architecture	2014-12-08 12:56:06 +08:00
nvdimm	libnvdimm: Non-Volatile Devices	2015-06-26 11:23:38 -04:00
nvmem	Documentation: nvmem: add nvmem api level and how-to doc	2015-08-05 13:43:45 -07:00
parisc
PCI	The documentation tree update for 4.1. Numerous fixes, the overdue removal	2015-04-18 11:10:49 -04:00
pcmcia	pcmcia: Fix typo in locking documentation	2015-08-07 14:34:58 +02:00
phy
platform
power	PCI / PM: Update runtime PM documentation for PCI devices	2015-09-25 02:48:44 +02:00
powerpc	SCSI misc on 20150901	2015-09-02 12:22:54 -07:00
pps	Doc: pps: Fix file name in pps.txt	2015-07-14 12:35:42 -06:00
prctl	Documentation/prctl: don't build tsc tests when cross compiling	2015-06-22 16:05:04 -06:00
pti
ptp	testptp: Silence compiler warnings on ppc64	2015-09-29 21:16:56 -07:00
rapidio
RCU	Merge branches 'doc.2015.10.06a', 'percpu-rwsem.2015.10.06a' and 'torture.2015.10.06a' into HEAD	2015-10-07 16:06:25 -07:00
s390	KVM: s390: remove outdated documentation	2015-07-29 11:02:35 +02:00
scheduler	sched/dl/Documentation: Split Section 3	2015-05-19 08:39:21 +02:00
scsi	Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block	2015-06-25 15:22:36 -07:00
security	KEYS: Merge the type-specific data with the payload data	2015-10-21 15:18:36 +01:00
serial	Documentation: improve line discipline method descriptions	2015-10-05 04:53:26 +01:00
sh
sound	Doc: sound:oss: Fix typo in sound/oss	2015-06-09 17:23:00 +02:00
spi	Documentation/spi/spidev_test.c: fix warning	2015-04-17 09:04:12 -04:00
sysctl	kernel/watchdog.c: perform all-CPU backtrace in case of hard lockup	2015-11-05 19:34:48 -08:00
target	Documentation/target: Fix tcm_mod_builder.py build breakage	2015-07-24 17:48:55 -07:00
thermal	thermal: power_allocator: relax the requirement of two passive trip points	2015-09-14 07:41:45 -07:00
timers	documentation: Update NO_HZ_FULL interaction with POSIX timers	2015-02-26 11:57:29 -08:00
tpm
trace	intel_th: Add driver infrastructure for Intel(R) Trace Hub devices	2015-10-04 20:28:58 +01:00
usb	usb: interface authorization: Documentation part	2015-09-22 12:08:40 -07:00
vDSO	Documentation/vDSO: don't build tests when cross compiling	2015-06-22 16:04:57 -06:00
video4linux	[media] media: videobuf2: Change queue_setup argument	2015-10-20 14:48:39 -02:00
virtual	s390: A bunch of fixes and optimizations for interrupt and time	2015-11-05 16:26:26 -08:00
vm	mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd	2015-11-06 17:50:42 -08:00
w1	w1: masters: omap_hdq: add support for 1-wire mode	2015-10-05 04:47:09 +01:00
watchdog	Documentation/watchdog: add timeout and ping rate control to watchdog-test.c	2015-09-09 21:33:36 +02:00
wimax
x86	Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-09-01 10:07:40 -07:00
xtensa
zh_CN	sysfs.txt: fix pre-kernfs sysfs_dirent reference	2015-09-13 14:38:50 -06:00
00-INDEX	Update of Documentation/dmaengine/00-INDEX	2014-12-29 15:28:24 -07:00
adding-syscalls.txt	Documentation: describe how to add a system call	2015-08-13 17:54:06 -06:00
applying-patches.txt
assoc_array.txt
atomic_ops.txt	locking/atomics, cmpxchg: Privatize the inclusion of asm/cmpxchg.h	2015-09-13 10:35:46 +02:00
bad_memory.txt
basic_profiling.txt
bcache.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt	rmap: drop support of non-linear mappings	2015-02-10 14:30:31 -08:00
Changes	There is a nice new document from Neil on how pathname lookups work and	2015-11-05 15:59:24 -08:00
circular-buffers.txt
clk.txt	clk: change clk_ops' ->determine_rate() prototype	2015-07-27 18:12:01 -07:00
coccinelle.txt
CodeOfConflict	Code of Conflict	2015-02-27 11:44:24 -08:00
CodingStyle	Documentation: CodingStyle: remove broken links in the References section	2015-07-10 13:54:34 -06:00
cpu-hotplug.txt	cpumask: fix cpu-hotplug documentation	2015-03-05 13:37:01 +10:30
cpu-load.txt
cputopology.txt	Documentation: Update cputopology.txt	2015-05-27 15:22:15 +02:00
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt	Doc: Change wikipedia's URL from http to https	2015-06-22 10:14:05 -06:00
dell_rbu.txt
devices.txt
digsig.txt
DMA-API-HOWTO.txt	Documentation: DMA API: Be more explicit that nents is always the same	2015-09-24 15:50:06 -06:00
DMA-API.txt	Documentation: DMA API: Be more explicit that nents is always the same	2015-09-24 15:50:06 -06:00
DMA-attributes.txt
dma-buf-sharing.txt	dma-buf: cleanup dma_buf_export() to make it easily extensible	2015-04-21 14:47:16 +05:30
DMA-ISA-LPC.txt
dontdiff
dynamic-debug-howto.txt
edac.txt	Documentation/EDAC: Add reference documents section for amd64_edac	2015-09-29 13:42:41 +02:00
efi-stub.txt
eisa.txt
email-clients.txt	Documentation/email-clients.txt: remove trailing whitespace	2015-10-11 15:31:57 -06:00
flexible-arrays.txt
futex-requeue-pi.txt	doc: Fix misnamed FUTEX_CMP_REQUEUE_PI op constants	2015-01-19 12:05:32 +01:00
gcov.txt
gdb-kernel-debugging.txt	scripts/gdb: add basic documentation	2015-02-17 14:34:54 -08:00
highuid.txt
HOWTO	docs: update HOWTO for 3.x -> 4.x versioning	2015-08-24 11:28:17 -06:00
hsi.txt
hw_random.txt	hwrng: doc - Fix device node name reference /dev/hw_random => /dev/hwrng	2015-09-21 22:00:41 +08:00
hwspinlock.txt	hwspinlock/core: add device tree support	2015-05-02 09:54:30 +03:00
init.txt
initrd.txt
intel_txt.txt
Intel-IOMMU.txt	x86/vt-d: Fix documentation of DRHD	2015-08-25 10:44:49 +02:00
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt	ipmi:ssif: Ignore spaces when comparing I2C adapter names	2015-05-05 14:24:45 -05:00
IRQ-affinity.txt
IRQ-domain.txt	irqdomain: Documentation updates	2015-10-13 19:01:25 +02:00
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kasan.txt	mm, slub, kasan: enable user tracking by default with KASAN=y	2015-11-05 19:34:48 -08:00
kernel-doc-nano-HOWTO.txt	Documenation: Update location of docproc.c	2015-07-14 12:36:39 -06:00
kernel-docs.txt	kernel-docs.txt: update kernelnewbies reference	2015-10-11 15:36:43 -06:00
kernel-parameters.txt	Merge branch 'akpm' (patches from Andrew)	2015-11-05 23:10:54 -08:00
kernel-per-CPU-kthreads.txt	documentation: Update per-CPU kthreads documentation	2015-02-26 11:57:30 -08:00
kmemcheck.txt	Documentation: update the CONFIG_DEBUG_PAGEALLOC description	2015-03-20 07:41:55 -06:00
kmemleak.txt	Doc: Change wikipedia's URL from http to https	2015-06-22 10:14:05 -06:00
kobject.txt	kobject: grammar fix	2014-12-08 09:07:11 -05:00
kprobes.txt	kprobes: Update Documentation/kprobes.txt	2015-03-20 07:41:55 -06:00
kref.txt
kselftest.txt	Documentation: Update kselftest.txt	2015-09-24 15:51:53 -06:00
ldm.txt
local_ops.txt	percpu: update local_ops.txt to reflect this_cpu operations	2014-12-13 12:42:53 -08:00
lockup-watchdogs.txt	kernel/watchdog.c: add sysctl knob hardlockup_panic	2015-11-05 19:34:48 -08:00
logo.gif
logo.txt
lzo.txt
magic-number.txt	Documentation/magic-number: Remove SCC_MAGIC	2015-05-13 15:39:04 -04:00
mailbox.txt	Documentation: minor typo fix in mailbox.txt	2015-08-13 18:03:18 -06:00
Makefile	Documentation: Remove ZBOOT MMC/SDHI utility and docs	2015-02-24 06:45:25 +09:00
ManagementStyle
md-cluster.txt	md-cluster: fix deadlock issue on message lock	2015-08-31 19:41:41 +02:00
md.txt	doc:md: fix typo in md.txt.	2015-06-23 06:49:44 -06:00
media-framework.txt
memory-barriers.txt	atomic: remove all traces of READ_ONCE_CTRL() and atomic*_read_ctrl()	2015-11-03 17:22:17 -08:00
memory-hotplug.txt	mem-hotplug: fix typo in Documentation/memory-hotplug.txt	2015-03-20 07:41:55 -06:00
men-chameleon-bus.txt	Documentation: Minor changes to men-chameleon-bus.txt	2015-07-24 15:15:17 +02:00
module-signing.txt	Move certificate handling to its own directory	2015-08-14 16:06:13 +01:00
mono.txt
nommu-mmap.txt	fs: introduce f_op->mmap_capabilities for nommu mmap support	2015-01-20 14:02:58 -07:00
ntb.txt	NTB: Rename Intel code names to platform names	2015-07-04 14:09:25 -04:00
numastat.txt
oops-tracing.txt	livepatch: kernel: add TAINT_LIVEPATCH	2014-12-22 15:40:48 +01:00
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt	phy: core: Add devm_of_phy_get_by_index to phy-core	2015-05-11 21:42:23 +05:30
pi-futex.txt
pinctrl.txt	pinctrl: move strict option to pinmux_ops	2015-05-06 14:45:19 +02:00
pnp.txt
preempt-locking.txt	x86/fpu: Rename math_state_restore() to fpu__restore()	2015-05-19 15:47:18 +02:00
printk-formats.txt	The documentation tree update for 4.1. Numerous fixes, the overdue removal	2015-04-18 11:10:49 -04:00
pwm.txt
ramoops.txt	pstore-ram: Allow optional mapping with pgprot_noncached	2014-12-11 13:38:31 -08:00
rbtree.txt	documentation: fix small typo in rbtree.txt	2015-09-13 14:38:50 -06:00
remoteproc.txt	remoteproc: introduce rproc_get_by_phandle API	2015-06-16 21:12:52 +03:00
rfkill.txt	rfkill: document rfkill module parameters	2015-01-09 23:22:12 +01:00
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt	Documentation, split up rtc.txt into documentation and test file	2015-03-24 22:01:58 -06:00
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
SM501.txt
smsc_ece1099.txt
sparse.txt
stable_api_nonsense.txt
stable_kernel_rules.txt	stable: Update documentation to clarify preferred procedure	2015-05-22 09:38:56 -06:00
static-keys.txt	locking/static_keys: Fix up the static keys documentation	2015-09-15 07:12:06 +02:00
SubmitChecklist
SubmittingDrivers
SubmittingPatches	SubmittingPatches: make Subject examples match the de facto standard	2015-09-24 15:57:42 -06:00
svga.txt
sysfs-rules.txt
sysrq.txt	mm, oom: do not panic for oom kills triggered from sysrq	2015-09-08 15:35:28 -07:00
this_cpu_ops.txt
unaligned-memory-access.txt
unicode.txt
unshare.txt
vfio.txt	vfio: powerpc/spapr: Support Dynamic DMA windows	2015-06-11 15:16:55 +10:00
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
vme_api.txt	Documentation: mention vme_master_mmap() in VME API	2015-06-12 17:26:56 -07:00
volatile-considered-harmful.txt
workqueue.txt	workqueue: fix trivial typo in Documentation/workqueue.txt	2015-05-05 09:50:38 -04:00
xillybus.txt
xz.txt
zorro.txt