linux/drivers
Michal Hocko 32d6bd9059 tree wide: get rid of __GFP_REPEAT for order-0 allocations part I
This is the third version of the patchset previously sent [1].  I have
basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
rid of superfluous gfp flags" which went through dm tree.  I am sending
it now because it is tree wide and chances for conflicts are reduced
considerably when we want to target rc2.  I plan to send the next step
and rename the flag and move to a better semantic later during this
release cycle so we will have a new semantic ready for 4.8 merge window
hopefully.

Motivation:

While working on something unrelated I've checked the current usage of
__GFP_REPEAT in the tree.  It seems that a majority of the usage is and
always has been bogus because __GFP_REPEAT has always been about costly
high order allocations while we are using it for order-0 or very small
orders very often.  It seems that a big pile of them is just a
copy&paste when a code has been adopted from one arch to another.

I think it makes some sense to get rid of them because they are just
making the semantic more unclear.  Please note that GFP_REPEAT is
documented as

* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt

* _might_ fail.  This depends upon the particular VM implementation.
  while !costly requests have basically nofail semantic.  So one could
  reasonably expect that order-0 request with __GFP_REPEAT will not loop
  for ever.  This is not implemented right now though.

I would like to move on with __GFP_REPEAT and define a better semantic
for it.

  $ git grep __GFP_REPEAT origin/master | wc -l
  111
  $ git grep __GFP_REPEAT | wc -l
  36

So we are down to the third after this patch series.  The remaining
places really seem to be relying on __GFP_REPEAT due to large allocation
requests.  This still needs some double checking which I will do later
after all the simple ones are sorted out.

I am touching a lot of arch specific code here and I hope I got it right
but as a matter of fact I even didn't compile test for some archs as I
do not have cross compiler for them.  Patches should be quite trivial to
review for stupid compile mistakes though.  The tricky parts are usually
hidden by macro definitions and thats where I would appreciate help from
arch maintainers.

[1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org

This patch (of 19):

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.  Yet we
have the full kernel tree with its usage for apparently order-0
allocations.  This is really confusing because __GFP_REPEAT is
explicitly documented to allow allocation failures which is a weaker
semantic than the current order-0 has (basically nofail).

Let's simply drop __GFP_REPEAT from those places.  This would allow to
identify place which really need allocator to retry harder and formulate
a more specific semantic for what the flag is supposed to do actually.

Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: John Crispin <blogic@openwrt.org>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-24 17:23:52 -07:00
..
accessibility
acpi Merge branch 'acpica-fixes' 2016-06-18 01:55:55 +02:00
amba
android
ata remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
atm atm: iphase: off by one in rx_pkt() 2016-05-31 11:52:59 -07:00
auxdisplay
base Driver core fixes for 4.7-rc4 2016-06-18 06:04:01 -10:00
bcma MTD updates for v4.7: 2016-05-24 11:00:20 -07:00
block tree wide: get rid of __GFP_REPEAT for order-0 allocations part I 2016-06-24 17:23:52 -07:00
bluetooth Bluetooth: Add USB ID 13D3:3487 to ath3k 2016-05-13 16:54:59 +02:00
bus Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-05-19 10:02:26 -07:00
cdrom
char ipmi: Remove smi_msg from waiting_rcv_msgs list before handle_one_recv_msg() 2016-06-13 08:56:28 -05:00
clk clk: nxp: Select MFD_SYSCON for creg driver 2016-06-01 15:14:06 -07:00
clocksource Small release overall. 2016-05-19 11:27:09 -07:00
connector
cpufreq cpufreq: intel_pstate: Adjust _PSS[0] freqeuency if needed 2016-06-15 01:56:47 +02:00
cpuidle cpuidle: Fix cpuidle_state_is_coupled() argument in cpuidle_enter() 2016-05-18 02:48:37 +02:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-05-30 15:20:18 -07:00
dax /dev/dax, core: file operations and dax-mmap 2016-05-20 22:02:55 -07:00
dca
devfreq
dio
dma dmaengine: mv_xor: Fix incorrect offset in dma_map_page() 2016-06-07 12:44:23 +05:30
dma-buf dma-buf: use vma_pages() 2016-05-31 22:17:05 +05:30
edac EDAC, sb_edac: Readd accidentally dropped Broadwell-D support 2016-06-03 17:28:21 +02:00
eisa
extcon extcon: palmas: Fix boot up state of VBUS when using GPIO detection 2016-06-15 17:17:22 +09:00
firewire
firmware efi/arm: Fix the format of EFI debug messages 2016-06-03 09:57:36 +02:00
fmc
fpga
gpio gpio: make library immune to error pointers 2016-06-23 00:29:31 +02:00
gpu drm/atomic: Make drm_atomic_legacy_backoff reset crtc->acquire_ctx 2016-06-24 11:10:36 +10:00
hid HID: multitouch: Add MT_QUIRK_NOT_SEEN_MEANS_UP to Surface Pro 3 2016-06-01 16:03:28 +02:00
hsi HSI: omap-ssi: move omap_ssi_port_update_fclk 2016-05-09 22:45:18 +02:00
hv
hwmon hwmon: (dell-smm) Disallow fan_type() calls on broken machines 2016-06-18 13:03:29 -07:00
hwspinlock drivers/hwspinlock: use correct radix tree API 2016-05-20 17:58:30 -07:00
hwtracing coresight: Handle build path error 2016-06-16 00:13:06 -07:00
i2c i2c: mux: reg: Provide of_match_table 2016-06-09 22:38:16 +02:00
ide
idle
iio Staging fixes for 4.7-rc4 2016-06-18 06:05:28 -10:00
infiniband IB/IPoIB: Don't update neigh validity for unresolved entries 2016-06-07 10:49:48 -04:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2016-05-27 19:14:35 -07:00
iommu iommu/vt-d: Enable QI on all IOMMUs before setting root entry 2016-06-17 11:29:48 +02:00
ipack
irqchip irqchip/irq-pic32-evic: Fix bug with external interrupts. 2016-06-02 18:03:50 +01:00
isdn TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
leds leds: handle suspend/resume in heartbeat trigger 2016-06-08 11:47:06 +02:00
lguest
lightnvm lightnvm: reserved space calculation incorrect 2016-05-06 12:51:10 -06:00
macintosh
mailbox mailbox: Fix devm_ioremap_resource error detection code 2016-05-08 22:44:46 +05:30
mcb mcb: Acquire reference to carrier module in core 2016-06-13 18:49:30 -07:00
md Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2016-05-27 14:28:09 -07:00
media Update my main e-mails at the Kernel tree 2016-06-15 15:35:37 -10:00
memory memory: omap-gpmc: Fix omap gpmc EXTRADELAY timing 2016-06-16 11:43:48 +03:00
memstick drivers/memstick/core/mspro_block: use kmemdup 2016-05-23 17:04:14 -07:00
message SCSI misc on 20160517 2016-05-18 16:38:59 -07:00
mfd remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
misc mei: don't use wake_up_interruptible for wr_ctrl 2016-06-10 22:14:24 -07:00
mmc mmc: sunxi: Re-enable eMMC HS-DDR modes on Allwinner A80 2016-06-02 10:40:20 +02:00
mtd ubi: Make recover_peb power cut aware 2016-06-23 00:29:32 +02:00
net vmxnet3: segCnt can be 1 for LRO packets 2016-06-10 00:15:11 -07:00
nfc NFC: pn533: handle interrupted commands in pn533_recv_frame 2016-05-10 00:01:47 +02:00
ntb
nubus
nvdimm DAX error handling for 4.7 2016-05-26 19:34:26 -07:00
nvme NVMe: Only release requested regions 2016-06-09 14:28:28 -06:00
nvmem remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
of drivers/of: Fix depth for sub-tree blob in unflatten_dt_nodes() 2016-06-09 14:36:34 -05:00
oprofile
parisc
parport
pci PCI: Fix unaligned accesses in VC code 2016-06-20 13:24:20 -05:00
pcmcia
perf arm: pmu: Fix non-devicetree probing 2016-06-15 09:51:35 +01:00
phy phy: for 4.7-rc 2016-06-10 23:06:21 -07:00
pinctrl pinctrl: mediatek: fix dual-edge code defect 2016-05-31 10:13:45 +02:00
platform platform/x86: Drop duplicate dependencies on X86 2016-06-08 13:21:37 -07:00
pnp driver core update for 4.7-rc1 2016-05-20 21:26:15 -07:00
power power supply and reset changes for the v4.7 series 2016-05-20 14:06:21 -07:00
powercap Power management material for v4.7-rc1 2016-05-16 19:17:22 -07:00
pps
ps3
ptp ptp: oops in ptp_ioctl() 2016-05-29 22:32:27 -07:00
pwm pwm: atmel-hlcdc: Fix default PWM polarity 2016-06-14 10:51:45 +02:00
rapidio
ras
regulator Merge remote-tracking branches 'regulator/fix/qcom-smd' and 'regulator/fix/tps51632' into regulator-linus 2016-06-13 16:51:57 +01:00
remoteproc remoteproc: Add additional crash reasons 2016-05-12 15:50:19 -07:00
reset
rpmsg rpmsg: add THIS_MODULE to rpmsg_driver in rpmsg core 2016-05-06 11:08:58 -07:00
rtc rtc: tps6586x: rename so module can be autoloaded 2016-05-21 17:07:17 +02:00
s390 DAX error handling for 4.7 2016-05-26 19:34:26 -07:00
sbus openprom: fix warning 2016-05-20 18:33:37 -07:00
scsi Merge remote-tracking branch 'mkp-scsi/4.7/scsi-fixes' into fixes 2016-06-04 09:53:29 -04:00
sfi
sh
sn
soc soc: mtk-pmic-wrap: avoid integer overflow warning 2016-05-19 15:20:24 +02:00
spi sound updates #2 for 4.7-rc1 2016-05-28 12:23:12 -07:00
spmi
ssb
staging Revert "Staging: rtl8188eu: rtw_efuse: Use sizeof type *pointer instead of sizeof type." 2016-06-17 11:21:45 -07:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-05-28 12:04:17 -07:00
tc
thermal Merge branch 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-06-12 06:30:39 -07:00
thunderbolt
tty devpts: Make each mount of devpts an independent filesystem. 2016-06-05 10:36:01 -07:00
uio
usb usbip: rate limit get_frame_number message 2016-06-17 18:00:46 -07:00
uwb
vfio vfio/pci: Allow VPD short read 2016-05-31 21:25:52 -06:00
vhost target: make close_session optional 2016-05-10 01:19:26 -07:00
video OMAPDSS: HDMI5: Change DDC timings 2016-05-31 08:20:43 +03:00
virt
virtio virtio_balloon: fix PFN format for virtio-1 2016-05-22 19:44:13 +03:00
vlynq
vme
w1
watchdog watchdog: ebc-c384_wdt: Allow build for X86_64 2016-06-17 20:21:12 -07:00
xen Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-05-28 12:04:17 -07:00
zorro
Kconfig libnvdimm for 4.7 2016-05-23 11:18:01 -07:00
Makefile /dev/dax, pmem: direct access to persistent memory 2016-05-20 22:02:53 -07:00