In some special cases we must not block, but there's not a spinlock,
preempt-off, irqs-off or similar critical section already that arms the
might_sleep() debug checks. Add a non_block_start/end() pair to annotate
these.
This will be used in the oom paths of mmu-notifiers, where blocking is not
allowed to make sure there's forward progress. Quoting Michal:
"The notifier is called from quite a restricted context - oom_reaper -
which shouldn't depend on any locks or sleepable conditionals. The code
should be swift as well but we mostly do care about it to make a forward
progress. Checking for sleepable context is the best thing we could come
up with that would describe these demands at least partially."
Peter also asked whether we want to catch spinlocks on top, but Michal
said those are less of a problem because spinlocks can't have an indirect
dependency upon the page allocator and hence close the loop with the oom
reaper.
Suggested by Michal Hocko.
Link: https://lore.kernel.org/r/20190826201425.17547-4-daniel.vetter@ffwll.ch
Acked-by: Christian König <christian.koenig@amd.com> (v1)
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Pull in v5.1-rc6 to resolve two conflicts. One is in BFQ, in just a
comment, and is trivial. The other one is a conflict due to a later fix
in the bio multi-page work, and needs a bit more care.
* tag 'v5.1-rc6': (770 commits)
Linux 5.1-rc6
block: make sure that bvec length can't be overflow
block: kill all_q_node in request_queue
x86/cpu/intel: Lower the "ENERGY_PERF_BIAS: Set to normal" message's log priority
coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping
mm/kmemleak.c: fix unused-function warning
init: initialize jump labels before command line option parsing
kernel/watchdog_hld.c: hard lockup message should end with a newline
kcov: improve CONFIG_ARCH_HAS_KCOV help text
mm: fix inactive list balancing between NUMA nodes and cgroups
mm/hotplug: treat CMA pages as unmovable
proc: fixup proc-pid-vm test
proc: fix map_files test on F29
mm/vmstat.c: fix /proc/vmstat format for CONFIG_DEBUG_TLBFLUSH=y CONFIG_SMP=n
mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock
mm: swapoff: shmem_unuse() stop eviction without igrab()
mm: swapoff: take notice of completion sooner
mm: swapoff: remove too limiting SWAP_UNUSE_MAX_TRIES
mm: swapoff: shmem_find_swap_entries() filter out other types
slab: store tagged freelist for off-slab slabmgmt
...
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently support for 64-bit sector_t and blkcnt_t is optional on 32-bit
architectures. These types are required to support block device and/or
file sizes larger than 2 TiB, and have generally defaulted to on for
a long time. Enabling the option only increases the i386 tinyconfig
size by 145 bytes, and many data structures already always use
64-bit values for their in-core and on-disk data structures anyway,
so there should not be a large change in dynamic memory usage either.
Dropping this option removes a somewhat weird non-default config that
has cause various bugs or compiler warnings when actually used.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The single quotation marks around "const" were causing a documentation
markup warning with reST. Instead of fixing that warning, just delete
that comment line and the gcc-3.3 hack of using "const" in the roundup()
macro since gcc-3.3 is no longer supported for kernel builds.
I did around 20 different $arch builds with no problems, but we'll just
have to see if this causes problems for anyone else out there.
Link: http://lkml.kernel.org/r/ec5dcf72-7c3e-3513-af0c-4003ed598854@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce cant_sleep() macro for annotation of functions that
cannot sleep.
Use it in BPF_PROG_RUN to catch execution of BPF programs in
preemptable context.
Suggested-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull staging/IIO updates from Greg KH:
"Here is the big staging and IIO driver update for 4.18-rc1.
It was delayed as I wanted to make sure the final driver deletions did
not cause any major merge issues, and all now looks good.
There are a lot of patches here, just over 1000. The diffstat summary
shows the major changes here:
1007 files changed, 16828 insertions(+), 227770 deletions(-)
Because of this, we might be close to shrinking the overall kernel
source code size for two releases in a row.
There was loads of work in this release cycle, primarily:
- tons of ks7010 driver cleanups
- lots of mt7621 driver fixes and cleanups
- most driver cleanups
- wilc1000 fixes and cleanups
- lots and lots of IIO driver cleanups and new additions
- debugfs cleanups for all staging drivers
- lots of other staging driver cleanups and fixes, the shortlog has
the full details.
but the big user-visable things here are the removal of 3 chunks of
code:
- ncpfs and ipx were removed on schedule, no one has cared about this
code since it moved to staging last year, and if it needs to come
back, it can be reverted.
- lustre file system is removed.
I've ranted at the lustre developers about once a year for the past
5 years, with no real forward progress at all to clean things up
and get the code into the "real" part of the kernel.
Given that the lustre developers continue to work on an external
tree and try to port those changes to the in-kernel tree every once
in a while, this whole thing really really is not working out at
all. So I'm deleting it so that the developers can spend the time
working in their out-of-tree location and get things cleaned up
properly to get merged into the tree correctly at a later date.
Because of these file removals, you will have merge issues on some of
these files (2 in the ipx code, 1 in the ncpfs code, and 1 in the
atomisp driver). Just delete those files, it's a simple merge :)
All of this has been in linux-next for a while with no reported
problems"
* tag 'staging-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1011 commits)
staging: ipx: delete it from the tree
ncpfs: remove uapi .h files
ncpfs: remove Documentation
ncpfs: remove compat functionality
staging: ncpfs: delete it
staging: lustre: delete the filesystem from the tree.
staging: vc04_services: no need to save the log debufs dentries
staging: vc04_services: vchiq_debugfs_log_entry can be a void *
staging: vc04_services: remove struct vchiq_debugfs_info
staging: vc04_services: move client dbg directory into static variable
staging: vc04_services: remove odd vchiq_debugfs_top() wrapper
staging: vc04_services: no need to check debugfs return values
staging: mt7621-gpio: reorder includes alphabetically
staging: mt7621-gpio: change gc_map to don't use pointers
staging: mt7621-gpio: use GPIOF_DIR_OUT and GPIOF_DIR_IN macros instead of custom values
staging: mt7621-gpio: change 'to_mediatek_gpio' to make just a one line return
staging: mt7621-gpio: dt-bindings: update documentation for #interrupt-cells property
staging: mt7621-gpio: update #interrupt-cells for the gpio node
staging: mt7621-gpio: dt-bindings: complete documentation for the gpio
staging: mt7621-dts: add missing properties to gpio node
...
timekeeping suspend/resume calls read_persistent_clock() which takes
rtc_lock. That results in might sleep warnings because at that point
we run with interrupts disabled.
We cannot convert rtc_lock to a raw spinlock as that would trigger
other might sleep warnings.
As a workaround we disable the might sleep warnings by setting
system_state to SYSTEM_SUSPEND before calling sysdev_suspend() and
restoring it to SYSTEM_RUNNING afer sysdev_resume(). There is no lock
contention because hibernate / suspend to RAM is single-CPU at this
point.
In s2idle's case the system_state is set to SYSTEM_SUSPEND before
timekeeping_suspend() which is invoked by the last CPU. In the resume
case it set back to SYSTEM_RUNNING after timekeeping_resume() which is
invoked by the first CPU in the resume case. The other CPUs will block
on tick_freeze_lock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: cover s2idle in tick_freeze() / tick_unfreeze()]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There aren't many users of this so it doesn't cause a problem, but we
obviously want to use "__mptr" here instead of "ptr" to prevent the
parameter from being executed twice.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Luster has a container_of0() function which is similar to
container_of() but passes an IS_ERR_OR_NULL() pointer through
unchanged.
This could be generally useful: bcache at last has a similar function.
Naming is hard, but the precedent set by hlist_entry_safe() suggests
a _safe suffix might be most consistent.
So add container_of_safe() to kernel.h, and replace all occurrences of
container_of0() with one of
- list_first_entry, list_next_entry, when that is a better fit,
- container_of(), when the pointer is used as a validpointer in
surrounding code,
- container_of_safe() when there is no obviously better alternative.
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
seq_put_decimal_ull_w(m, str, val, width) prints a decimal number with a
specified minimal field width.
It is equivalent of seq_printf(m, "%s%*d", str, width, val), but it
works much faster.
== test_smaps.py
num = 0
with open("/proc/1/smaps") as f:
for x in xrange(10000):
data = f.read()
f.seek(0, 0)
==
== Before patch ==
$ time python test_smaps.py
real 0m4.593s
user 0m0.398s
sys 0m4.158s
== After patch ==
$ time python test_smaps.py
real 0m3.828s
user 0m0.413s
sys 0m3.408s
$ perf -g record python test_smaps.py
== Before patch ==
- 79.01% 3.36% python [kernel.kallsyms] [k] show_smap.isra.33
- 75.65% show_smap.isra.33
+ 48.85% seq_printf
+ 15.75% __walk_page_range
+ 9.70% show_map_vma.isra.23
0.61% seq_puts
== After patch ==
- 75.51% 4.62% python [kernel.kallsyms] [k] show_smap.isra.33
- 70.88% show_smap.isra.33
+ 24.82% seq_put_decimal_ull_w
+ 19.78% __walk_page_range
+ 12.74% seq_printf
+ 11.08% show_map_vma.isra.23
+ 1.68% seq_puts
[akpm@linux-foundation.org: fix drivers/of/unittest.c build]
Link: http://lkml.kernel.org/r/20180212074931.7227-1-avagin@openvz.org
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
