Pull nfsd updates from Bruce Fields:
"Chuck's RDMA update overhauls the "call receive" side of the
RPC-over-RDMA transport to use the new rdma_rw API.
Christoph cleaned the way nfs operations are declared, removing a
bunch of function-pointer casts and declaring the operation vectors as
const.
Christoph's changes touch both client and server, and both client and
server pulls this time around should be based on the same commits from
Christoph"
* tag 'nfsd-4.13' of git://linux-nfs.org/~bfields/linux: (53 commits)
svcrdma: fix an incorrect check on -E2BIG and -EINVAL
nfsd4: factor ctime into change attribute
svcrdma: Remove svc_rdma_chunk_ctxt::cc_dir field
svcrdma: use offset_in_page() macro
svcrdma: Clean up after converting svc_rdma_recvfrom to rdma_rw API
svcrdma: Clean-up svc_rdma_unmap_dma
svcrdma: Remove frmr cache
svcrdma: Remove unused Read completion handlers
svcrdma: Properly compute .len and .buflen for received RPC Calls
svcrdma: Use generic RDMA R/W API in RPC Call path
svcrdma: Add recvfrom helpers to svc_rdma_rw.c
sunrpc: Allocate up to RPCSVC_MAXPAGES per svc_rqst
svcrdma: Don't account for Receive queue "starvation"
svcrdma: Improve Reply chunk sanity checking
svcrdma: Improve Write chunk sanity checking
svcrdma: Improve Read chunk sanity checking
svcrdma: Remove svc_rdma_marshal.c
svcrdma: Avoid Send Queue overflow
svcrdma: Squelch disconnection messages
sunrpc: Disable splice for krb5i
...
Pull ext2, udf, reiserfs fixes from Jan Kara:
"Several ext2, udf, and reiserfs fixes"
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
ext2: Fix memory leak when truncate races ext2_get_blocks
reiserfs: fix race in prealloc discard
reiserfs: don't preallocate blocks for extended attributes
udf: Convert udf_disk_stamp_to_time() to use mktime64()
udf: Use time64_to_tm for timestamp conversion
udf: Fix deadlock between writeback and udf_setsize()
udf: Use i_size_read() in udf_adinicb_writepage()
udf: Fix races with i_size changes during readpage
udf: Remove unused UDF_DEFAULT_BLOCKSIZE
Pull documentation fixes from Jonathan Corbet:
"A set of fixes for various warnings, including the one caused by the
removal of kernel/rcu/srcu.c. Also correct a stray pointer in
memory-barriers.txt"
* tag '4.13-fixes' of git://git.lwn.net/linux:
kokr/memory-barriers.txt: Fix obsolete link to atomic_ops.txt
memory-barriers.txt: Fix broken link to atomic_ops.txt
docs: Turn off section numbering for the input docs
docs: Include uaccess docs from the right file
docs: Do not include from kernel/rcu/srcu.c
Pull more Kbuild updates from Masahiro Yamada:
- Move generic-y of exported headers to uapi/asm/Kbuild for complete
de-coupling of UAPI
- Clean up scripts/Makefile.headersinst
- Fix host programs for 32 bit machine with XFS file system
* tag 'kbuild-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (29 commits)
kbuild: Enable Large File Support for hostprogs
kbuild: remove wrapper files handling from Makefile.headersinst
kbuild: split exported generic header creation into uapi-asm-generic
kbuild: do not include old-kbuild-file from Makefile.headersinst
xtensa: move generic-y of exported headers to uapi/asm/Kbuild
unicore32: move generic-y of exported headers to uapi/asm/Kbuild
tile: move generic-y of exported headers to uapi/asm/Kbuild
sparc: move generic-y of exported headers to uapi/asm/Kbuild
sh: move generic-y of exported headers to uapi/asm/Kbuild
parisc: move generic-y of exported headers to uapi/asm/Kbuild
openrisc: move generic-y of exported headers to uapi/asm/Kbuild
nios2: move generic-y of exported headers to uapi/asm/Kbuild
nios2: remove unneeded arch/nios2/include/(generated/)asm/signal.h
microblaze: move generic-y of exported headers to uapi/asm/Kbuild
metag: move generic-y of exported headers to uapi/asm/Kbuild
m68k: move generic-y of exported headers to uapi/asm/Kbuild
m32r: move generic-y of exported headers to uapi/asm/Kbuild
ia64: remove redundant generic-y += kvm_para.h from asm/Kbuild
hexagon: move generic-y of exported headers to uapi/asm/Kbuild
h8300: move generic-y of exported headers to uapi/asm/Kbuild
...
Pull more tracing updates from Steven Rostedt:
"A few more minor updates:
- Show the tgid mappings for user space trace tools to use
- Fix and optimize the comm and tgid cache recording
- Sanitize derived kprobe names
- Ftrace selftest updates
- trace file header fix
- Update of Documentation/trace/ftrace.txt
- Compiler warning fixes
- Fix possible uninitialized variable"
* tag 'trace-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Fix uninitialized variable in match_records()
ftrace: Remove an unneeded NULL check
ftrace: Hide cached module code for !CONFIG_MODULES
tracing: Do note expose stack_trace_filter without DYNAMIC_FTRACE
tracing: Update Documentation/trace/ftrace.txt
tracing: Fixup trace file header alignment
selftests/ftrace: Add a testcase for kprobe event naming
selftests/ftrace: Add a test to probe module functions
selftests/ftrace: Update multiple kprobes test for powerpc
trace/kprobes: Sanitize derived event names
tracing: Attempt to record other information even if some fail
tracing: Treat recording tgid for idle task as a success
tracing: Treat recording comm for idle task as a success
tracing: Add saved_tgids file to show cached pid to tgid mappings
Merge yet more updates from Andrew Morton:
- various misc things
- kexec updates
- sysctl core updates
- scripts/gdb udpates
- checkpoint-restart updates
- ipc updates
- kernel/watchdog updates
- Kees's "rough equivalent to the glibc _FORTIFY_SOURCE=1 feature"
- "stackprotector: ascii armor the stack canary"
- more MM bits
- checkpatch updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits)
writeback: rework wb_[dec|inc]_stat family of functions
ARM: samsung: usb-ohci: move inline before return type
video: fbdev: omap: move inline before return type
video: fbdev: intelfb: move inline before return type
USB: serial: safe_serial: move __inline__ before return type
drivers: tty: serial: move inline before return type
drivers: s390: move static and inline before return type
x86/efi: move asmlinkage before return type
sh: move inline before return type
MIPS: SMP: move asmlinkage before return type
m68k: coldfire: move inline before return type
ia64: sn: pci: move inline before type
ia64: move inline before return type
FRV: tlbflush: move asmlinkage before return type
CRIS: gpio: move inline before return type
ARM: HP Jornada 7XX: move inline before return type
ARM: KVM: move asmlinkage before type
checkpatch: improve the STORAGE_CLASS test
mm, migration: do not trigger OOM killer when migrating memory
drm/i915: use __GFP_RETRY_MAYFAIL
...
Pull VFIO updates from Alex Williamson:
- Include Intel XXV710 in INTx workaround (Alex Williamson)
- Make use of ERR_CAST() for error return (Dan Carpenter)
- Fix vfio_group release deadlock from iommu notifier (Alex Williamson)
- Unset KVM-VFIO attributes only on group match (Alex Williamson)
- Fix release path group/file matching with KVM-VFIO (Alex Williamson)
- Remove unnecessary lock uses triggering lockdep splat (Alex Williamson)
* tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio:
vfio: Remove unnecessary uses of vfio_container.group_lock
vfio: New external user group/file match
kvm-vfio: Decouple only when we match a group
vfio: Fix group release deadlock
vfio: Use ERR_CAST() instead of open coding it
vfio/pci: Add Intel XXV710 to hidden INTx devices
Pull RTC updates from Alexandre Belloni:
"Here is the pull-request for the RTC subsystem for 4.13.
Subsystem:
- expose non volatile RAM using nvmem instead of open coding in many
drivers. Unfortunately, this option has to be enabled by default to
not break existing users.
- rtctest can now test for cutoff dates, showing when an RTC will
start failing to properly save time and date.
- new RTC registration functions to remove race conditions in drivers
Newly supported RTCs:
- Broadcom STB wake-timer
- Epson RX8130CE
- Maxim IC DS1308
- STMicroelectronics STM32H7
Drivers:
- ds1307: use regmap, use nvmem, more cleanups
- ds3232: temperature reading support
- gemini: renamed to ftrtc010
- m41t80: use CCF to expose the clock
- rv8803: use nvmem
- s3c: many cleanups
- st-lpc: fix y2106 bug"
* tag 'rtc-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (51 commits)
rtc: Remove wrong deprecation comment
nvmem: include linux/err.h from header
rtc: st-lpc: make it robust against y2038/2106 bug
rtc: rtctest: add check for problematic dates
tools: timer: add rtctest_setdate
rtc: ds1307: remove ds1307_remove
rtc: ds1307: use generic nvmem
rtc: ds1307: switch to rtc_register_device
rtc: rv8803: remove rv8803_remove
rtc: rv8803: use generic nvmem support
rtc: rv8803: switch to rtc_register_device
rtc: add generic nvmem support
rtc: at91rm9200: remove race condition
rtc: introduce new registration method
rtc: class separate id allocation from registration
rtc: class separate device allocation from registration
rtc: stm32: add STM32H7 RTC support
dt-bindings: rtc: stm32: add support for STM32H7
rtc: ds1307: add ds1308 variant
rtc: ds3232: add temperature support
...
Pull MTD updates from Brian Norris:
"General updates:
- Cleanups and additional flash support for "dataflash" driver
- new driver for mchp23k256 SPI SRAM device
- improve handling of MTDs without eraseblocks (i.e., MTD_NO_ERASE)
- refactor and improve "sub-partition" handling with TRX partition
parser; partitions can now be created as sub-partitions of another
partition
SPINOR updates, from Cyrille Pitchen and Marek Vasut:
- introduce support to the SPI 1-2-2 and 1-4-4 protocols.
- introduce support to the Double Data Rate (DDR) mode.
- introduce support to the Octo SPI protocols.
- add support to new memory parts for Spansion, Macronix and Winbond.
- add fixes for the Aspeed, STM32 and Cadence QSPI controler drivers.
- clean up the st_spi_fsm driver.
NAND updates, from Boris Brezillon:
- addition of on-die ECC support to Micron driver
- addition of helpers to help drivers choose most appropriate ECC
settings
- deletion of dead-code (cached programming and ->errstat() hook)
- make sure drivers that do not support the SET/GET FEATURES command
return ENOTSUPP use a dummy ->set/get_features implementation
returning -ENOTSUPP (required for Micron on-die ECC)
- change the semantic of ecc->write_page() for drivers setting the
NAND_ECC_CUSTOM_PAGE_ACCESS flag
- support exiting 'GET STATUS' command in default ->cmdfunc()
implementations
- change the prototype of ->setup_data_interface()
A bunch of driver related changes:
- various cleanup, fixes and improvements of the MTK driver
- OMAP DT bindings fixes
- support for ->setup_data_interface() in the fsmc driver
- support for imx7 in the gpmi driver
- finalization of the denali driver rework (thanks to Masahiro for
the work he's done on this driver)
- fix "bitflips in erased pages" handling in the ifc driver
- addition of PM ops and dynamic timing configuration to the atmel
driver"
* tag 'for-linus-20170713' of git://git.infradead.org/linux-mtd: (118 commits)
Documentation: ABI: mtd: describe "offset" more precisely
mtd: Fix check in mtd_unpoint()
mtd: nand: mtk: release lock on error path
mtd: st_spi_fsm: remove SPINOR_OP_RDSR2 and use SPINOR_OP_RDCR instead
mtd: spi-nor: cqspi: remove duplicate const
mtd: spi-nor: Add support for Spansion S25FL064L
mtd: spi-nor: Add support for mx66u51235f
mtd: nand: mtk: add ->setup_data_interface() hook
mtd: nand: mtk: remove unneeded mtk_ecc_hw_init from mtk_ecc_resume
mtd: nand: mtk: remove unneeded mtk_nfc_hw_init from mtk_nfc_resume
mtd: nand: mtk: disable ecc irq when writing page with hwecc
mtd: nand: mtk: fix incorrect register setting order about ecc irq
mtd: partitions: fixup some allocate_partition() whitespace
mtd: parsers: trx: fix pr_err format for printing offset
MAINTAINERS: Update SPI NOR subsystem git repositories
mtd: extract TRX parser out of bcm47xxpart into a separated module
mtd: partitions: add support for partition parsers
mtd: partitions: add support for subpartitions
mtd: partitions: rename "master" to the "parent" where appropriate
mtd: partitions: remove sysfs files when deleting all master's partitions
...
Pull pwm updates from Thierry Reding:
"This release cycle's changes include mostly updates and cleanups to
existing drivers along with a few cleanups to the core, documentation
and device tree bindings"
* tag 'pwm/for-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
pwm: cros-ec: Fix transposed param settings
pwm: meson: Improve PWM calculation precision
dt-bindings: pwm: meson: Add compatible for gxbb ao PWMs
pwm: meson: Add compatible for the gxbb ao PWMs
pwm: sun4i: Drop legacy callbacks
pwm: sun4i: Switch to atomic PWM
pwm: sun4i: Improve hardware read out
pwm: hibvt: Constify hibvt_pwm_ops
pwm: Silently error out on EPROBE_DEFER
pwm: Standardize document format
pwm: bfin: Remove unneeded error message
dt-bindings: pwm: Update STM32 timers clock names
dt-bindings: pwm: Add R-Car M3-W device tree bindings
pwm: tegra: Set maximum pwm clock source per SoC tapeout
Pull power supply fixes from Reichel:
"I have two more fixes for the power-supply subsystem:
- two fixes for twl4030-charger"
* tag 'for-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply:
power: supply: twl4030-charger: add deferred probing for phy and iio
power: supply: twl4030-charger: move irq allocation to just before irqs are enabled
Pull more drm updates from Dave Airlie:
"i915, amd and some core fixes + mediatek color support.
Some fixes tree came in since the main pull request for rc1, primarily
i915 and drm-misc and one amd fix. The drm core vblank regression fix
is probably the most important thing.
I've also added the mediatek feature pull, it wasn't that big and
didn't look like it would have any impact outside of mediatek, in fact
it looks to just be a single feature, and some cleanups"
* tag 'drm-fixes-for-v4.13-rc1' of git://people.freedesktop.org/~airlied/linux: (31 commits)
drm/i915: Make DP-MST connector info work
drm/i915/gvt: Use fence error from GVT request for workload status
drm/i915/gvt: remove scheduler_mutex in per-engine workload_thread
drm/i915/gvt: Revert "drm/i915/gvt: Fix possible recursive locking issue"
drm/i915/gvt: Audit the command buffer address
drm/i915/gvt: Fix a memory leak in intel_gvt_init_gtt()
drm/rockchip: fix NULL check on devm_kzalloc() return value
drm/i915/fbdev: Check for existence of ifbdev->vma before operations
drm/radeon: Fix eDP for single-display iMac10,1 (v2)
drm/i915: Hold RPM wakelock while initializing OA buffer
drm/i915/cnl: Fix the CURSOR_COEFF_MASK used in DDI Vswing Programming
drm/i915/cfl: Fix Workarounds.
drm/i915: Avoid undefined behaviour of "u32 >> 32"
drm/i915: reintroduce VLV/CHV PFI programming power domain workaround
drm/i915: Fix an error checking test
drm/i915: Disable MSI for all pre-gen5
drm/atomic: Add missing drm_atomic_state_clear to atomic_remove_fb
drm: vblank: Fix vblank timestamp update
drm/i915/gvt: Make function dpy_reg_mmio_readx safe
drm/mediatek: separate color module to fixup error memory reallocation
...
The current check will always be true and will always jump to
err1, this looks dubious to me. I believe && should be used
instead of ||.
Detected by CoverityScan, CID#1450120 ("Logically Dead Code")
Fixes: 107c1d0a99 ("svcrdma: Avoid Send Queue overflow")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
So far Linux supported only two levels of MTD devices so we didn't need
a very precise description for this sysfs file. With commit
97519dc52b ("mtd: partitions: add support for subpartitions") there
is support for a tree structure so we should have more precise
description. Using "parent" and "flash device" makes it more accurate.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Buffer heads referencing indirect blocks may not be released if the file
is truncated at the right time. This happens because ext2_get_branch()
returns NULL when it finds the whole chain of indirect blocks already
set, and when truncate alters the chain this value of NULL is
treated as the address of the last head to be released. Handle this in the
same way as it's done after the got_it label.
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Pull sysctl fix from Eric Biederman:
"A rather embarassing and hard to hit bug was merged into 4.11-rc1.
Andrei Vagin tracked this bug now and after some staring at the code
I came up with a fix"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
proc: Fix proc_sys_prune_dcache to hold a sb reference
Pull networking fixes from David Miller:
1) Fix 64-bit division in mlx5 IPSEC offload support, from Ilan Tayari
and Arnd Bergmann.
2) Fix race in statistics gathering in bnxt_en driver, from Michael
Chan.
3) Can't use a mutex in RCU reader protected section on tap driver, from
Cong WANG.
4) Fix mdb leak in bridging code, from Eduardo Valentin.
5) Fix free of wrong pointer variable in nfp driver, from Dan Carpenter.
6) Buffer overflow in brcmfmac driver, from Arend van SPriel.
7) ioremap_nocache() return value needs to be checked in smsc911x
driver, from Alexey Khoroshilov.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (34 commits)
net: stmmac: revert "support future possible different internal phy mode"
sfc: don't read beyond unicast address list
datagram: fix kernel-doc comments
socket: add documentation for missing elements
smsc911x: Add check for ioremap_nocache() return code
brcmfmac: fix possible buffer overflow in brcmf_cfg80211_mgmt_tx()
net: hns: Bugfix for Tx timeout handling in hns driver
net: ipmr: ipmr_get_table() returns NULL
nfp: freeing the wrong variable
mlxsw: spectrum_switchdev: Check status of memory allocation
mlxsw: spectrum_switchdev: Remove unused variable
mlxsw: spectrum_router: Fix use-after-free in route replace
mlxsw: spectrum_router: Add missing rollback
samples/bpf: fix a build issue
bridge: mdb: fix leak on complete_info ptr on fail path
tap: convert a mutex to a spinlock
cxgb4: fix BUG() on interrupt deallocating path of ULD
qed: Fix printk option passed when printing ipv6 addresses
net: Fix minor code bug in timestamping.txt
net: stmmac: Make 'alloc_dma_[rt]x_desc_resources()' look even closer
...
I made the mistake of upgrading my desktop to the new Fedora 26 that
comes with gcc-7.1.1.
There's nothing wrong per se that I've noticed, but I now have 1500
lines of warnings, mostly from the new format-truncation warning
triggering all over the tree.
We use 'snprintf()' and friends in a lot of places, and often know that
the numbers are fairly small (ie a controller index or similar), but gcc
doesn't know that, and sees an 'int', and thinks that it could be some
huge number. And then complains when our buffers are not able to fit
the name for the ten millionth controller.
These warnings aren't necessarily bad per se, and we probably want to
look through them subsystem by subsystem, but at least during the merge
window they just mean that I can't even see if somebody is introducing
any *real* problems when I pull.
So warnings disabled for now.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drm/i915 fixes for v4.13-rc1
* tag 'drm-intel-next-fixes-2017-07-11' of git://anongit.freedesktop.org/git/drm-intel:
drm/i915: Make DP-MST connector info work
drm/i915/gvt: Use fence error from GVT request for workload status
drm/i915/gvt: remove scheduler_mutex in per-engine workload_thread
drm/i915/gvt: Revert "drm/i915/gvt: Fix possible recursive locking issue"
drm/i915/gvt: Audit the command buffer address
drm/i915/gvt: Fix a memory leak in intel_gvt_init_gtt()
drm/i915/fbdev: Check for existence of ifbdev->vma before operations
drm/i915: Hold RPM wakelock while initializing OA buffer
drm/i915/cnl: Fix the CURSOR_COEFF_MASK used in DDI Vswing Programming
drm/i915/cfl: Fix Workarounds.
drm/i915: Avoid undefined behaviour of "u32 >> 32"
drm/i915: reintroduce VLV/CHV PFI programming power domain workaround
drm/i915: Fix an error checking test
drm/i915: Disable MSI for all pre-gen5
drm/i915/gvt: Make function dpy_reg_mmio_readx safe
drm/i915/gvt: Don't read ADPA_CRT_HOTPLUG_MONITOR from host
drm/i915/gvt: Set initial PORT_CLK_SEL vreg for BDW
drm/i915/gvt: Fix inconsistent locks holding sequence
drm/i915/gvt: Fix possible recursive locking issue
This include new color format support and some fixups.
* 'mediatek-drm-next-4.13' of https://github.com/ckhu-mediatek/linux.git-tags:
drm/mediatek: separate color module to fixup error memory reallocation
drm/mediatek: check for memory allocation failure
drm/mediatek: re-phrase DRM_INFO error message
drm/mediatek: use platform_register_drivers
drm/mediatek: Support UYVY and YUYV format for overlay
Pull modules updates from Jessica Yu:
"Summary of modules changes for the 4.13 merge window:
- Minor code cleanups
- Avoid accessing mod struct prior to checking module struct version,
from Kees
- Fix racy atomic inc/dec logic of kmod_concurrent_max in kmod, from
Luis"
* tag 'modules-for-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: make the modinfo name const
kmod: reduce atomic operations on kmod_concurrent and simplify
module: use list_for_each_entry_rcu() on find_module_all()
kernel/module.c: suppress warning about unused nowarn variable
module: Add module name to modinfo
module: Pass struct load_info into symbol checks
Currently the writeback statistics code uses a percpu counters to hold
various statistics. Furthermore we have 2 families of functions - those
which disable local irq and those which doesn't and whose names begin
with double underscore. However, they both end up calling
__add_wb_stats which in turn calls percpu_counter_add_batch which is
already irq-safe.
Exploiting this fact allows to eliminated the __wb_* functions since
they don't add any further protection than we already have.
Furthermore, refactor the wb_* function to call __add_wb_stat directly
without the irq-disabling dance. This will likely result in better
runtime of code which deals with modifying the stat counters.
While at it also document why percpu_counter_add_batch is in fact
preempt and irq-safe since at least 3 people got confused.
Link: http://lkml.kernel.org/r/1498029937-27293-1-git-send-email-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to
the page allocator. This has been true but only for allocations
requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always
ignored for smaller sizes. This is a bit unfortunate because there is
no way to express the same semantic for those requests and they are
considered too important to fail so they might end up looping in the
page allocator for ever, similarly to GFP_NOFAIL requests.
Now that the whole tree has been cleaned up and accidental or misled
usage of __GFP_REPEAT flag has been removed for !costly requests we can
give the original flag a better name and more importantly a more useful
semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user
that the allocator would try really hard but there is no promise of a
success. This will work independent of the order and overrides the
default allocator behavior. Page allocator users have several levels of
guarantee vs. cost options (take GFP_KERNEL as an example)
- GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_
attempt to free memory at all. The most light weight mode which even
doesn't kick the background reclaim. Should be used carefully because
it might deplete the memory and the next user might hit the more
aggressive reclaim
- GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic
allocation without any attempt to free memory from the current
context but can wake kswapd to reclaim memory if the zone is below
the low watermark. Can be used from either atomic contexts or when
the request is a performance optimization and there is another
fallback for a slow path.
- (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) -
non sleeping allocation with an expensive fallback so it can access
some portion of memory reserves. Usually used from interrupt/bh
context with an expensive slow path fallback.
- GFP_KERNEL - both background and direct reclaim are allowed and the
_default_ page allocator behavior is used. That means that !costly
allocation requests are basically nofail but there is no guarantee of
that behavior so failures have to be checked properly by callers
(e.g. OOM killer victim is allowed to fail currently).
- GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior
and all allocation requests fail early rather than cause disruptive
reclaim (one round of reclaim in this implementation). The OOM killer
is not invoked.
- GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator
behavior and all allocation requests try really hard. The request
will fail if the reclaim cannot make any progress. The OOM killer
won't be triggered.
- GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior
and all allocation requests will loop endlessly until they succeed.
This might be really dangerous especially for larger orders.
Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL
because they already had their semantic. No new users are added.
__alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if
there is no progress and we have already passed the OOM point.
This means that all the reclaim opportunities have been exhausted except
the most disruptive one (the OOM killer) and a user defined fallback
behavior is more sensible than keep retrying in the page allocator.
[akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c]
[mhocko@suse.com: semantic fix]
Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz
[mhocko@kernel.org: address other thing spotted by Vlastimil]
Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: give __GFP_REPEAT a better semantic".
The main motivation for the change is that the current implementation of
__GFP_REPEAT is not very much useful.
The documentation says:
* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
* _might_ fail. This depends upon the particular VM implementation.
It just fails to mention that this is true only for large (costly) high
order which has been the case since the flag was introduced. A similar
semantic would be really helpful for smal orders as well, though,
because we have places where a failure with a specific fallback error
handling is preferred to a potential endless loop inside the page
allocator.
The earlier cleanup dropped __GFP_REPEAT usage for low (!costly) order
users so only those which might use larger orders have stayed. One new
user added in the meantime is addressed in patch 1.
Let's rename the flag to something more verbose and use it for existing
users. Semantic for those will not change. Then implement low
(!costly) orders failure path which is hit after the page allocator is
about to invoke the oom killer. With that we have a good counterpart
for __GFP_NORETRY and finally can tell try as hard as possible without
the OOM killer.
Xfs code already has an existing annotation for allocations which are
allowed to fail and we can trivially map them to the new gfp flag
because it will provide the semantic KM_MAYFAIL wants. Christoph didn't
consider the new flag really necessary but didn't respond to the OOM
killer aspect of the change so I have kept the patch. If this is still
seen as not really needed I can drop the patch.
kvmalloc will allow also !costly high order allocations to retry hard
before falling back to the vmalloc.
drm/i915 asked for the new semantic explicitly.
Memory migration code, especially for the memory hotplug, should back
off rather than invoking the OOM killer as well.
This patch (of 6):
Commit 3377e227af ("MIPS: Add 48-bit VA space (and 4-level page
tables) for 4K pages.") has added a new __GFP_REPEAT user but using this
flag doesn't really make any sense for order-0 request which is the case
here because PUD_ORDER is 0. __GFP_REPEAT has historically effect only
on allocation requests with order > PAGE_ALLOC_COSTLY_ORDER.
This doesn't introduce any functional change. This is a preparatory
patch for later work which renames the flag and redefines its semantic.
Link: http://lkml.kernel.org/r/20170623085345.11304-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
