Pull MM updates from Andrew Morton:
- Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
switching from a user process to a kernel thread.
- More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
Raghav.
- zsmalloc performance improvements from Sergey Senozhatsky.
- Yue Zhao has found and fixed some data race issues around the
alteration of memcg userspace tunables.
- VFS rationalizations from Christoph Hellwig:
- removal of most of the callers of write_one_page()
- make __filemap_get_folio()'s return value more useful
- Luis Chamberlain has changed tmpfs so it no longer requires swap
backing. Use `mount -o noswap'.
- Qi Zheng has made the slab shrinkers operate locklessly, providing
some scalability benefits.
- Keith Busch has improved dmapool's performance, making part of its
operations O(1) rather than O(n).
- Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
permitting userspace to wr-protect anon memory unpopulated ptes.
- Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
rather than exclusive, and has fixed a bunch of errors which were
caused by its unintuitive meaning.
- Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
which causes minor faults to install a write-protected pte.
- Vlastimil Babka has done some maintenance work on vma_merge():
cleanups to the kernel code and improvements to our userspace test
harness.
- Cleanups to do_fault_around() by Lorenzo Stoakes.
- Mike Rapoport has moved a lot of initialization code out of various
mm/ files and into mm/mm_init.c.
- Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
DRM, but DRM doesn't use it any more.
- Lorenzo has also coverted read_kcore() and vread() to use iterators
and has thereby removed the use of bounce buffers in some cases.
- Lorenzo has also contributed further cleanups of vma_merge().
- Chaitanya Prakash provides some fixes to the mmap selftesting code.
- Matthew Wilcox changes xfs and afs so they no longer take sleeping
locks in ->map_page(), a step towards RCUification of pagefaults.
- Suren Baghdasaryan has improved mmap_lock scalability by switching to
per-VMA locking.
- Frederic Weisbecker has reworked the percpu cache draining so that it
no longer causes latency glitches on cpu isolated workloads.
- Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
logic.
- Liu Shixin has changed zswap's initialization so we no longer waste a
chunk of memory if zswap is not being used.
- Yosry Ahmed has improved the performance of memcg statistics
flushing.
- David Stevens has fixed several issues involving khugepaged,
userfaultfd and shmem.
- Christoph Hellwig has provided some cleanup work to zram's IO-related
code paths.
- David Hildenbrand has fixed up some issues in the selftest code's
testing of our pte state changing.
- Pankaj Raghav has made page_endio() unneeded and has removed it.
- Peter Xu contributed some rationalizations of the userfaultfd
selftests.
- Yosry Ahmed has fixed an issue around memcg's page recalim
accounting.
- Chaitanya Prakash has fixed some arm-related issues in the
selftests/mm code.
- Longlong Xia has improved the way in which KSM handles hwpoisoned
pages.
- Peter Xu fixes a few issues with uffd-wp at fork() time.
- Stefan Roesch has changed KSM so that it may now be used on a
per-process and per-cgroup basis.
* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
shmem: restrict noswap option to initial user namespace
mm/khugepaged: fix conflicting mods to collapse_file()
sparse: remove unnecessary 0 values from rc
mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
maple_tree: fix allocation in mas_sparse_area()
mm: do not increment pgfault stats when page fault handler retries
zsmalloc: allow only one active pool compaction context
selftests/mm: add new selftests for KSM
mm: add new KSM process and sysfs knobs
mm: add new api to enable ksm per process
mm: shrinkers: fix debugfs file permissions
mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
migrate_pages_batch: fix statistics for longterm pin retry
userfaultfd: use helper function range_in_vma()
lib/show_mem.c: use for_each_populated_zone() simplify code
mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
fs/buffer: convert create_page_buffers to folio_create_buffers
fs/buffer: add folio_create_empty_buffers helper
...
%pGp format is used to display 'flags' field of a struct page. However,
some page flags (i.e. PG_buddy, see page-flags.h for more details) are
stored in page_type field. To display human-readable output of page_type,
introduce %pGt format.
It is important to note the meaning of bits are different in page_type.
if page_type is 0xffffffff, no flags are set. Setting PG_buddy
(0x00000080) flag results in a page_type of 0xffffff7f. Clearing a bit
actually means setting a flag. Bits in page_type are inverted when
displaying type names.
Only values for which page_type_has_type() returns true are considered as
page_type, to avoid confusion with mapcount values. if it returns false,
only raw values are displayed and not page type names.
Link: https://lkml.kernel.org/r/20230130042514.2418-3-42.hyeyoo@gmail.com
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com> [vsprintf part]
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull random number generator updates from Jason Donenfeld:
- Replace prandom_u32_max() and various open-coded variants of it,
there is now a new family of functions that uses fast rejection
sampling to choose properly uniformly random numbers within an
interval:
get_random_u32_below(ceil) - [0, ceil)
get_random_u32_above(floor) - (floor, U32_MAX]
get_random_u32_inclusive(floor, ceil) - [floor, ceil]
Coccinelle was used to convert all current users of
prandom_u32_max(), as well as many open-coded patterns, resulting in
improvements throughout the tree.
I'll have a "late" 6.1-rc1 pull for you that removes the now unused
prandom_u32_max() function, just in case any other trees add a new
use case of it that needs to converted. According to linux-next,
there may be two trivial cases of prandom_u32_max() reintroductions
that are fixable with a 's/.../.../'. So I'll have for you a final
conversion patch doing that alongside the removal patch during the
second week.
This is a treewide change that touches many files throughout.
- More consistent use of get_random_canary().
- Updates to comments, documentation, tests, headers, and
simplification in configuration.
- The arch_get_random*_early() abstraction was only used by arm64 and
wasn't entirely useful, so this has been replaced by code that works
in all relevant contexts.
- The kernel will use and manage random seeds in non-volatile EFI
variables, refreshing a variable with a fresh seed when the RNG is
initialized. The RNG GUID namespace is then hidden from efivarfs to
prevent accidental leakage.
These changes are split into random.c infrastructure code used in the
EFI subsystem, in this pull request, and related support inside of
EFISTUB, in Ard's EFI tree. These are co-dependent for full
functionality, but the order of merging doesn't matter.
- Part of the infrastructure added for the EFI support is also used for
an improvement to the way vsprintf initializes its siphash key,
replacing an sleep loop wart.
- The hardware RNG framework now always calls its correct random.c
input function, add_hwgenerator_randomness(), rather than sometimes
going through helpers better suited for other cases.
- The add_latent_entropy() function has long been called from the fork
handler, but is a no-op when the latent entropy gcc plugin isn't
used, which is fine for the purposes of latent entropy.
But it was missing out on the cycle counter that was also being mixed
in beside the latent entropy variable. So now, if the latent entropy
gcc plugin isn't enabled, add_latent_entropy() will expand to a call
to add_device_randomness(NULL, 0), which adds a cycle counter,
without the absent latent entropy variable.
- The RNG is now reseeded from a delayed worker, rather than on demand
when used. Always running from a worker allows it to make use of the
CPU RNG on platforms like S390x, whose instructions are too slow to
do so from interrupts. It also has the effect of adding in new inputs
more frequently with more regularity, amounting to a long term
transcript of random values. Plus, it helps a bit with the upcoming
vDSO implementation (which isn't yet ready for 6.2).
- The jitter entropy algorithm now tries to execute on many different
CPUs, round-robining, in hopes of hitting even more memory latencies
and other unpredictable effects. It also will mix in a cycle counter
when the entropy timer fires, in addition to being mixed in from the
main loop, to account more explicitly for fluctuations in that timer
firing. And the state it touches is now kept within the same cache
line, so that it's assured that the different execution contexts will
cause latencies.
* tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits)
random: include <linux/once.h> in the right header
random: align entropy_timer_state to cache line
random: mix in cycle counter when jitter timer fires
random: spread out jitter callback to different CPUs
random: remove extraneous period and add a missing one in comments
efi: random: refresh non-volatile random seed when RNG is initialized
vsprintf: initialize siphash key using notifier
random: add back async readiness notifier
random: reseed in delayed work rather than on-demand
random: always mix cycle counter in add_latent_entropy()
hw_random: use add_hwgenerator_randomness() for early entropy
random: modernize documentation comment on get_random_bytes()
random: adjust comment to account for removed function
random: remove early archrandom abstraction
random: use random.trust_{bootloader,cpu} command line option only
stackprotector: actually use get_random_canary()
stackprotector: move get_random_canary() into stackprotector.h
treewide: use get_random_u32_inclusive() when possible
treewide: use get_random_u32_{above,below}() instead of manual loop
treewide: use get_random_u32_below() instead of deprecated function
...
Rather than polling every second, use the new notifier to do this at
exactly the right moment.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Pull printk updates from Petr Mladek:
- Initialize pointer hashing using the system workqueue. It avoids
taking locks in printk()/vsprintf() code path
- Misc code clean up
* tag 'printk-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: Mark __printk percpu data ready __ro_after_init
printk: Remove bogus comment vs. boot consoles
printk: Remove write only variable nr_ext_console_drivers
printk: Declare log_wait properly
printk: Make pr_flush() static
lib/vsprintf: Initialize vsprintf's pointer hash once the random core is ready.
lib/vsprintf: Remove static_branch_likely() from __ptr_to_hashval().
lib/vnsprintf: add const modifier for param 'bitmap'
The printk code invokes vnsprintf in order to compute the complete
string before adding it into its buffer. This happens in an IRQ-off
region which leads to a warning on PREEMPT_RT in the random code if the
format strings contains a %p for pointer printing. This happens because
the random core acquires locks which become sleeping locks on PREEMPT_RT
which must not be acquired with disabled interrupts and or preemption
disabled.
By default the pointers are hashed which requires a random value on the
first invocation (either by printk or another user which comes first.
One could argue that there is no need for printk to disable interrupts
during the vsprintf() invocation which would fix the just mentioned
problem. However printk itself can be invoked in a context with
disabled interrupts which would lead to the very same problem.
Move the initialization of ptr_key into a worker and schedule it from
subsys_initcall(). This happens early but after the workqueue subsystem
is ready. Use get_random_bytes() to retrieve the random value if the RNG
core is ready, otherwise schedule a worker in two seconds and try again.
Another advantage is that it removes a lock from the vsprintf() code path.
It prevents a possible deadlock when printk("%p", ptr) is called under
the lock taken in get_random_bytes().
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
[pmladek@suse.com: Added a note about the it prevented a possible deadlock in printk().]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220927104912.622645-3-bigeasy@linutronix.de
This patch adds a format specifier `%pA` to `vsprintf` which formats
a pointer as `core::fmt::Arguments`. Doing so allows us to directly
format to the internal buffer of `printf`, so we do not have to use
a temporary buffer on the stack to pre-assemble the message on
the Rust side.
This specifier is intended only to be used from Rust and not for C, so
`checkpatch.pl` is intentionally unchanged to catch any misuse.
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
With arch randomness being used by every distro and enabled in
defconfigs, the distinction between rng_has_arch_random() and
rng_is_initialized() is now rather small. In fact, the places where they
differ are now places where paranoid users and system builders really
don't want arch randomness to be used, in which case we should respect
that choice, or places where arch randomness is known to be broken, in
which case that choice is all the more important. So this commit just
removes the function and its one user.
Reviewed-by: Petr Mladek <pmladek@suse.com> # for vsprintf.c
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
The register_random_ready_notifier() notifier is somewhat complicated,
and was already recently rewritten to use notifier blocks. It is only
used now by one consumer in the kernel, vsprintf.c, for which the async
mechanism is really overly complex for what it actually needs. This
commit removes register_random_ready_notifier() and unregister_random_
ready_notifier(), because it just adds complication with little utility,
and changes vsprintf.c to just check on `!rng_is_initialized() &&
!rng_has_arch_random()`, which will eventually be true. Performance-
wise, that code was already using a static branch, so there's basically
no overhead at all to this change.
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Petr Mladek <pmladek@suse.com> # for vsprintf.c
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
The RNG incorporates RDRAND into its state at boot and every time it
reseeds, so there's no reason for callers to use it directly. The
hashing that the RNG does on it is preferable to using the bytes raw.
The only current use case of get_random_bytes_arch() is vsprintf's
siphash key for pointer hashing, which uses it to initialize the pointer
secret earlier than usual if RDRAND is available. In order to replace
this narrow use case, just expose whether RDRAND is mixed into the RNG,
with a new function called rng_has_arch_random(). With that taken care
of, there are no users of get_random_bytes_arch() left, so it can be
removed.
Later, if trust_cpu gets turned on by default (as most distros are
doing), this one use of rng_has_arch_random() can probably go away as
well.
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Petr Mladek <pmladek@suse.com> # for vsprintf.c
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Patch series "mm/page_owner: Extend page_owner to show memcg information", v4.
While debugging the constant increase in percpu memory consumption on a
system that spawned large number of containers, it was found that a lot
of offline mem_cgroup structures remained in place without being freed.
Further investigation indicated that those mem_cgroup structures were
pinned by some pages.
In order to find out what those pages are, the existing page_owner
debugging tool is extended to show memory cgroup information and whether
those memcgs are offline or not. With the enhanced page_owner tool, the
following is a typical page that pinned the mem_cgroup structure in my
test case:
Page allocated via order 0, mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 162970 (podman), ts 1097761405537 ns, free_ts 1097760838089 ns
PFN 1925700 type Movable Block 3761 type Movable Flags 0x17ffffc00c001c(uptodate|dirty|lru|reclaim|swapbacked|node=0|zone=2|lastcpupid=0x1fffff)
prep_new_page+0xac/0xe0
get_page_from_freelist+0x1327/0x14d0
__alloc_pages+0x191/0x340
alloc_pages_vma+0x84/0x250
shmem_alloc_page+0x3f/0x90
shmem_alloc_and_acct_page+0x76/0x1c0
shmem_getpage_gfp+0x281/0x940
shmem_write_begin+0x36/0xe0
generic_perform_write+0xed/0x1d0
__generic_file_write_iter+0xdc/0x1b0
generic_file_write_iter+0x5d/0xb0
new_sync_write+0x11f/0x1b0
vfs_write+0x1ba/0x2a0
ksys_write+0x59/0xd0
do_syscall_64+0x37/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Charged to offline memcg libpod-conmon-15e4f9c758422306b73b2dd99f9d50a5ea53cbb16b4a13a2c2308a4253cc0ec8.
So the page was not freed because it was part of a shmem segment. That
is useful information that can help users to diagnose similar problems.
With cgroup v1, /proc/cgroups can be read to find out the total number
of memory cgroups (online + offline). With cgroup v2, the cgroup.stat
of the root cgroup can be read to find the number of dying cgroups (most
likely pinned by dying memcgs).
The page_owner feature is not supposed to be enabled for production
system due to its memory overhead. However, if it is suspected that
dying memcgs are increasing over time, a test environment with
page_owner enabled can then be set up with appropriate workload for
further analysis on what may be causing the increasing number of dying
memcgs.
This patch (of 4):
For *scnprintf(), vsnprintf() is always called even if the input size is
0. That is a waste of time, so just return 0 in this case.
Note that vsnprintf() will never return -1 to indicate an error. So
skipping the call to vsnprintf() when size is 0 will have no functional
impact at all.
Link: https://lkml.kernel.org/r/20220202203036.744010-1-longman@redhat.com
Link: https://lkml.kernel.org/r/20220202203036.744010-2-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull printk updates from Petr Mladek:
- Make %pK behave the same as %p for kptr_restrict == 0 also with
no_hash_pointers parameter
- Ignore the default console in the device tree also when console=null
or console="" is used on the command line
- Document console=null and console="" behavior
- Prevent a deadlock and a livelock caused by console_lock in panic()
- Make console_lock available for panicking CPU
- Fast query for the next to-be-used sequence number
- Use the expected return values in printk.devkmsg __setup handler
- Use the correct atomic operations in wake_up_klogd() irq_work handler
- Avoid possible unaligned access when handling %4cc printing format
* tag 'printk-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: fix return value of printk.devkmsg __setup handler
vsprintf: Fix %pK with kptr_restrict == 0
printk: make suppress_panic_printk static
printk: Set console_set_on_cmdline=1 when __add_preferred_console() is called with user_specified == true
Docs: printk: add 'console=null|""' to admin/kernel-parameters
printk: use atomic updates for klogd work
printk: Drop console_sem during panic
printk: Avoid livelock with heavy printk during panic
printk: disable optimistic spin during panic
printk: Add panic_in_progress helper
vsprintf: Move space out of string literals in fourcc_string()
vsprintf: Fix potential unaligned access
printk: ringbuffer: Improve prb_next_seq() performance
We previously rolled our own randomness readiness notifier, which only
has two users in the whole kernel. Replace this with a more standard
atomic notifier block that serves the same purpose with less code. Also
unexport the symbols, because no modules use it, only unconditional
builtins. The only drawback is that it's possible for a notification
handler returning the "stop" code to prevent further processing, but
given that there are only two users, and that we're unexporting this
anyway, that doesn't seem like a significant drawback for the
simplification we receive here.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Although kptr_restrict is set to 0 and the kernel is booted with
no_hash_pointers parameter, the content of /proc/vmallocinfo is
lacking the real addresses.
/ # cat /proc/vmallocinfo
0x(ptrval)-0x(ptrval) 8192 load_module+0xc0c/0x2c0c pages=1 vmalloc
0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc
0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc
0x(ptrval)-0x(ptrval) 8192 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap
0x(ptrval)-0x(ptrval) 12288 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap
...
According to the documentation for /proc/sys/kernel/, %pK is
equivalent to %p when kptr_restrict is set to 0.
Fixes: 5ead723a20 ("lib/vsprintf: no_hash_pointers prints all addresses as unhashed")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/107476128e59bff11a309b5bf7579a1753a41aca.1645087605.git.christophe.leroy@csgroup.eu
Pull bitmap updates from Yury Norov:
- introduce for_each_set_bitrange()
- use find_first_*_bit() instead of find_next_*_bit() where possible
- unify for_each_bit() macros
* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
vsprintf: rework bitmap_list_string
lib: bitmap: add performance test for bitmap_print_to_pagebuf
bitmap: unify find_bit operations
mm/percpu: micro-optimize pcpu_is_populated()
Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
find: micro-optimize for_each_{set,clear}_bit()
include/linux: move for_each_bit() macros from bitops.h to find.h
cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
tools: sync tools/bitmap with mother linux
all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
cpumask: use find_first_and_bit()
lib: add find_first_and_bit()
arch: remove GENERIC_FIND_FIRST_BIT entirely
include: move find.h from asm_generic to linux
bitops: move find_bit_*_le functions from le.h to find.h
bitops: protect find_first_{,zero}_bit properly
bitmap_list_string() is very ineffective when printing bitmaps with long
ranges of set bits because it calls find_next_bit for each bit in the
bitmap. We can do better by detecting ranges of set bits.
In my environment, before/after is 943008/31008 ns.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
