Linus Torvalds 596ff4a09b cpumask: re-introduce constant-sized cpumask optimizations ... Commit aa47a7c215 ("lib/cpumask: deprecate nr_cpumask_bits") resulted in the cpumask operations potentially becoming hugely less efficient, because suddenly the cpumask was always considered to be variable-sized. The optimization was then later added back in a limited form by commit 6f9c07be9d ("lib/cpumask: add FORCE_NR_CPUS config option"), but that FORCE_NR_CPUS option is not useful in a generic kernel and more of a special case for embedded situations with fixed hardware. Instead, just re-introduce the optimization, with some changes. Instead of depending on CPUMASK_OFFSTACK being false, and then always using the full constant cpumask width, this introduces three different cpumask "sizes": - the exact size (nr_cpumask_bits) remains identical to nr_cpu_ids. This is used for situations where we should use the exact size. - the "small" size (small_cpumask_bits) is the NR_CPUS constant if it fits in a single word and the bitmap operations thus end up able to trigger the "small_const_nbits()" optimizations. This is used for the operations that have optimized single-word cases that get inlined, notably the bit find and scanning functions. - the "large" size (large_cpumask_bits) is the NR_CPUS constant if it is an sufficiently small constant that makes simple "copy" and "clear" operations more efficient. This is arbitrarily set at four words or less. As a an example of this situation, without this fixed size optimization, cpumask_clear() will generate code like movl nr_cpu_ids(%rip), %edx addq $63, %rdx shrq $3, %rdx andl $-8, %edx callq memset@PLT on x86-64, because it would calculate the "exact" number of longwords that need to be cleared. In contrast, with this patch, using a MAX_CPU of 64 (which is quite a reasonable value to use), the above becomes a single movq $0,cpumask instruction instead, because instead of caring to figure out exactly how many CPU's the system has, it just knows that the cpumask will be a single word and can just clear it all. Note that this does end up tightening the rules a bit from the original version in another way: operations that set bits in the cpumask are now limited to the actual nr_cpu_ids limit, whereas we used to do the nr_cpumask_bits thing almost everywhere in the cpumask code. But if you just clear bits, or scan for bits, we can use the simpler compile-time constants. In the process, remove 'cpumask_complement()' and 'for_each_cpu_not()' which were not useful, and which fundamentally have to be limited to 'nr_cpu_ids'. Better remove them now than have somebody introduce use of them later. Of course, on x86-64 with MAXSMP there is no sane small compile-time constant for the cpumask sizes, and we end up using the actual CPU bits, and will generate the above kind of horrors regardless. Please don't use MAXSMP unless you really expect to have machines with thousands of cores. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2023-03-05 14:30:34 -08:00
..
842
crypto	crypto: lib/blake2s - Split up test function to halve stack usage	2022-12-30 22:56:27 +08:00
dim	dim: initialize all struct fields	2022-05-09 17:20:37 -07:00
fonts	lib/fonts: fix undefined behavior in bit shift for get_default_font	2022-11-18 13:55:09 -08:00
kunit	kunit: Fix 'hooks.o' build by recursing into kunit	2023-02-27 14:49:03 -08:00
livepatch	selftests/livepatch: better synchronize test_klp_callbacks_busy	2022-06-15 10:29:10 +02:00
lz4	lib: make LZ4_decompress_safe_forceExtDict() static	2022-07-17 17:31:39 -07:00
lzo	lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t()	2022-07-29 18:12:34 -07:00
math	math64: favor kernel-doc from header files	2022-11-21 14:30:53 -07:00
mpi	lib/mpi: Fix buffer overrun when SG is too long	2023-01-06 17:15:46 +08:00
pldmfw
raid6	for-6.2/block-2022-12-08	2022-12-13 10:43:59 -08:00
reed_solomon	treewide: use get_random_u32_below() instead of deprecated function	2022-11-18 02:15:15 +01:00
test_fortify	fortify: Detect struct member overflows in memset() at compile-time	2022-02-13 16:50:06 -08:00
vdso	lib/vdso: use "grep -E" instead of "egrep"	2022-11-23 19:50:15 +01:00
xz
zlib_deflate	lib/zlib: DFLTCC deflate does not write all available bits for Z_NO_FLUSH	2023-02-27 17:00:14 -08:00
zlib_dfltcc	lib/zlib: remove redundation assignement of avail_in dfltcc_gdht()	2023-02-02 22:50:10 -08:00
zlib_inflate	lib/zlib: Split deflate and inflate states for DFLTCC	2023-02-02 22:50:09 -08:00
zstd	zstd: import usptream v1.5.2	2022-10-24 12:12:32 -07:00
.gitignore	bootconfig: Support embedding a bootconfig file in kernel	2022-04-26 17:58:51 -04:00
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c
asn1_encoder.c
assoc_array.c	assoc_array: Fix BUG_ON during garbage collect	2022-06-01 18:29:06 -07:00
atomic64_test.c
atomic64.c
audit.c
base64.c	lib/base64: RFC4648-compliant base64 encoding	2022-08-02 17:14:47 -06:00
bcd.c
bch.c
bitfield_kunit.c
bitmap.c	lib/bitmap: remove bitmap_ord_to_pos	2022-09-26 12:19:12 -07:00
bitrev.c
bootconfig-data.S	bootconfig: Support embedding a bootconfig file in kernel	2022-04-26 17:58:51 -04:00
bootconfig.c	bootconfig: Support embedding a bootconfig file in kernel	2022-04-26 17:58:51 -04:00
bsearch.c
btree.c	lib/btree: simplify btree_{lookup|update}	2022-06-16 19:58:21 -07:00
bucket_locks.c
bug.c	cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG	2023-01-31 15:01:45 +01:00
build_OID_registry
buildid.c
bust_spinlocks.c	kernel/panic: Drop unblank_screen call	2022-09-01 16:55:35 +02:00
check_signature.c
checksum.c
clz_ctz.c
clz_tab.c
cmdline_kunit.c	treewide: use get_random_{u8,u16}() when possible, part 1	2022-10-11 17:42:58 -06:00
cmdline.c	lib/cmdline: avoid page fault in next_arg	2022-09-11 21:55:06 -07:00
cmpdi2.c
compat_audit.c
cpu_rmap.c
cpumask_kunit.c	cpumask: re-introduce constant-sized cpumask optimizations	2023-03-05 14:30:34 -08:00
cpumask.c	lib/cpumask: update comment for cpumask_local_spread()	2023-02-07 18:20:00 -08:00
crc4.c
crc7.c
crc8.c
crc16.c
crc32.c
crc32defs.h
crc32test.c
crc64-rocksoft.c	crypto: add rocksoft 64b crc guard tag framework	2022-03-07 12:48:35 -07:00
crc64.c	lib: add rocksoft model crc64	2022-03-07 12:48:35 -07:00
crc-ccitt.c
crc-itu-t.c	crc-itu-t: fix typo in CRC ITU-T polynomial comment	2022-06-07 10:27:38 +02:00
crc-t10dif.c
ctype.c
debug_info.c
debug_locks.c
debugobjects.c	Non-MM patches for 6.2-rc1.	2022-12-12 17:28:58 -08:00
dec_and_lock.c	perf: Fix perf_event_pmu_context serialization	2023-01-31 20:37:18 +01:00
decompress_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress_unzstd.c
decompress.c
devmem_is_allowed.c
devres.c	devres: remove devm_ioremap_np	2022-09-01 18:04:43 +02:00
dhry_1.c	lib: add Dhrystone benchmark test	2023-02-02 22:50:01 -08:00
dhry_2.c	lib: add Dhrystone benchmark test	2023-02-02 22:50:01 -08:00
dhry_run.c	lib: add Dhrystone benchmark test	2023-02-02 22:50:01 -08:00
dhry.h	lib: add Dhrystone benchmark test	2023-02-02 22:50:01 -08:00
digsig.c
dump_stack.c	printk: rename cpulock functions	2022-04-22 21:30:57 +02:00
dynamic_debug.c	dyndbg: add drm.debug style (drm/parameters/debug) bitmap support	2022-09-07 17:04:49 +02:00
dynamic_queue_limits.c
earlycpio.c	lib: move from strlcpy with unused retval to strscpy	2022-09-11 21:55:10 -07:00
errname.c	printf: fix errname.c list	2023-02-15 15:44:43 +01:00
error-inject.c	error-injection: remove EI_ETYPE_NONE	2023-02-02 22:50:00 -08:00
errseq.c
extable.c
fault-inject-usercopy.c
fault-inject.c	fault-injection: make stacktrace filter works as expected	2022-12-15 16:40:44 -08:00
fdt_addresses.c
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit_benchmark.c	treewide: use get_random_u32_below() instead of deprecated function	2022-11-18 02:15:15 +01:00
find_bit.c	lib/find: introduce find_nth_and_andnot_bit	2023-02-07 18:20:00 -08:00
flex_proportions.c	flex_proportions: Disable preemption entering the write section.	2022-09-19 14:35:08 +02:00
fortify_kunit.c	kunit/fortify: Validate __alloc_size attribute results	2022-11-22 21:08:28 -08:00
gen_crc32table.c
gen_crc64table.c	lib: add rocksoft model crc64	2022-03-07 12:48:35 -07:00
genalloc.c	lib/genalloc: use try_cmpxchg in {set,clear}_bits_ll	2023-02-02 22:50:05 -08:00
generic-radix-tree.c
glob.c	lib: remove back_str initialization	2022-04-29 14:38:01 -07:00
globtest.c
group_cpus.c	genirq/affinity: Only build SMP-only helper functions on SMP kernels	2023-01-18 12:16:47 +01:00
hashtable_test.c	lib/hashtable_test.c: add test for the hashtable structure	2023-02-08 14:28:17 -07:00
hexdump.c	hex2bin: fix access beyond string end	2022-04-27 10:57:33 -07:00
hweight.c
idr.c	ida: don't use BUG_ON() for debugging	2022-07-10 13:55:49 -07:00
inflate.c
interval_tree_test.c
interval_tree.c	interval-tree: Add a utility to iterate over spans in an interval tree	2022-11-29 16:34:15 -04:00
iomap_copy.c
iomap.c	kmsan: add iomap support	2022-10-03 14:03:21 -07:00
iommu-helper.c
iov_iter.c	46 fs/cifs (smb3 client) changesets, 37 in fs/cifs and 9 for related helper functions and cleanup outside from Dave Howells and Willy	2023-02-22 17:12:44 -08:00
irq_poll.c	lib/irq_poll: Prevent softirq pending leak in irq_poll_cpu_dead()	2022-04-13 21:32:21 +02:00
irq_regs.c
is_signed_type_kunit.c	lib: assume char is unsigned	2022-11-19 00:56:15 +01:00
is_single_threaded.c
kasprintf.c
Kconfig	iommufd for 6.2	2022-12-14 09:15:43 -08:00
Kconfig.debug	There is no particular theme here - mainly quick hits all over the tree.	2023-02-23 17:55:40 -08:00
Kconfig.kasan	kasan: treat meminstrinsic as builtins in uninstrumented files	2023-03-02 21:54:22 -08:00
Kconfig.kcsan	Kernel concurrency sanitizer (KCSAN) updates for v6.3	2023-02-25 13:02:20 -08:00
Kconfig.kfence	kfence: allow use of a deferrable timer	2022-03-22 15:57:11 -07:00
Kconfig.kgdb	parisc: Convert PDC console to an early console	2022-10-11 12:01:24 +02:00
Kconfig.kmsan	kmsan: make sure PREEMPT_RT is off	2022-11-08 15:57:24 -08:00
Kconfig.ubsan	ubsan: disable UBSAN_DIV_ZERO for clang	2022-07-14 15:45:26 -07:00
kfifo.c
klist.c
kobject_uevent.c
kobject.c	kobject: make dynamic_kobj_ktype and kset_ktype const	2023-02-08 13:34:20 +01:00
kstrtox.c	lib/kstrtox.c: add "false"/"true" support to kstrtobool()	2022-05-13 07:20:13 -07:00
kstrtox.h
libcrc32c.c
linear_ranges.c
list_debug.c	lib/list_debug.c: Detect uninitialized lists	2022-06-16 19:58:20 -07:00
list_sort.c
list-test.c	list: test: Test the hlist structure	2022-04-05 13:32:27 -06:00
llist.c	llist: avoid extra memory read in llist_add_batch	2022-11-18 13:55:06 -08:00
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-rtmutex.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c
lockref.c	lockref: stop doing cpu_relax in the cmpxchg loop	2023-01-13 14:35:38 -06:00
logic_iomem.c	lib/logic_iomem: correct fallback config references	2022-03-11 10:42:56 +01:00
logic_pio.c
lru_cache.c	lru_cache: remove unused lc_private, lc_set, lc_index_of	2022-11-22 19:38:39 -07:00
lshrdi3.c
Makefile	kunit: Fix 'hooks.o' build by recursing into kunit	2023-02-27 14:49:03 -08:00
maple_tree.c	maple_tree: reduce stack usage with gcc-9 and earlier	2023-02-16 20:43:55 -08:00
memcat_p.c
memcpy_kunit.c	kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST	2023-01-25 12:24:40 -08:00
memory-notifier-error-inject.c
memregion.c
memweight.c
muldi3.c
net_utils.c	mac_pton: Don't access memory over expected length	2022-11-09 19:28:02 -08:00
netdev-notifier-error-inject.c
nlattr.c	netlink: prevent potential spectre v1 gadgets	2023-01-20 17:52:32 -08:00
nmi_backtrace.c	x86/nmi: Print reasons why backtrace NMIs are ignored	2023-01-19 15:55:12 -08:00
notifier-error-inject.c	lib/notifier-error-inject: fix error when writing -errno to debugfs file	2022-11-30 16:13:16 -08:00
notifier-error-inject.h
objagg.c
of-reconfig-notifier-error-inject.c
oid_registry.c	lib/oid_registry.c: remove redundant assignment to variable num	2022-11-18 13:55:06 -08:00
once.c	once: rename _SLOW to _SLEEPABLE	2022-10-03 17:34:32 -07:00
overflow_kunit.c	overflow: Introduce overflows_type() and castable_to_type()	2022-11-02 12:39:27 -07:00
packing.c	lib: packing: replace bit_reverse() with bitrev8()	2022-12-12 15:06:30 -08:00
parman.c
parser.c	lib: parser: update documentation for match_NUMBER functions	2023-03-02 21:54:22 -08:00
pci_iomap.c
percpu_counter.c	lib/percpu_counter: percpu_counter_add_batch() overflow/underflow	2023-02-02 22:50:01 -08:00
percpu_test.c
percpu-refcount.c	percpu-refcount: Use call_rcu_hurry() for atomic switch	2022-11-30 13:16:40 -08:00
plist.c
pm-notifier-error-inject.c
polynomial.c	lib: add generic polynomial calculation	2022-05-22 11:32:30 -07:00
radix-tree.c	lib/radix-tree.c: fix uninitialized variable compilation warning	2022-11-30 16:13:17 -08:00
random32.c	treewide: use get_random_bytes() when possible	2022-10-11 17:42:58 -06:00
ratelimit.c	ratelimit: Fix data-races in ___ratelimit().	2022-08-24 13:46:57 +01:00
rbtree_test.c
rbtree.c
ref_tracker.c	ref_tracker: remove filter_irq_stacks() call	2022-02-06 11:05:28 +00:00
refcount.c
rhashtable.c	rhashtable: Allow rhashtable to be used from irq-safe contexts	2022-12-09 10:42:56 +00:00
sbitmap.c	sbitmap: correct wake_batch recalculation to avoid potential IO hung	2023-01-29 20:03:01 -07:00
scatterlist.c	lib/scatterlist: Fix to calculate the last_pg properly	2023-01-16 12:08:31 -04:00
seq_buf.c
sg_pool.c	lib/sg_pool: change module_init(sg_pool_init) to subsys_initcall	2022-09-23 16:46:19 +02:00
sg_split.c
show_mem.c	mm: reduce noise in show_mem for lowmem allocations	2022-09-26 19:46:29 -07:00
siphash_kunit.c	siphash: Convert selftest to KUnit	2022-11-01 10:04:52 -07:00
siphash.c	SPDX changes for 5.19-rc1	2022-06-03 10:34:34 -07:00
slub_kunit.c	linux-kselftest-kunit-next-6.2-rc1	2022-12-12 16:42:57 -08:00
smp_processor_id.c	lib/smp_processor_id: fix imbalanced instrumentation_end() call	2022-07-17 17:31:41 -07:00
sort.c	lib/sort: Add priv pointer to swap function	2022-03-17 20:17:18 -07:00
stackdepot.c	lib/stackdepot: move documentation comments to stackdepot.h	2023-02-16 20:43:52 -08:00
stackinit_kunit.c	kernel/range: Uplevel the cxl subsystem's range_contains() helper	2023-02-10 17:32:37 -08:00
stmp_device.c
string_helpers.c	lib/string_helpers: Introduce parse_int_array_user()	2022-09-05 14:51:46 +01:00
string.c	lib/string: Use strchr() in strpbrk()	2023-01-27 11:42:57 -08:00
strncpy_from_user.c	lib/strn*,objtool: Enforce user_access_begin() rules	2022-04-19 21:58:47 +02:00
strnlen_user.c	lib/strn*,objtool: Enforce user_access_begin() rules	2022-04-19 21:58:47 +02:00
strscpy_kunit.c	fortify: Short-circuit known-safe calls to strscpy()	2022-11-01 10:04:52 -07:00
syscall.c
test_bitmap.c	lib/bitmap: add tests for for_each() loops	2022-10-01 10:22:58 -07:00
test_bitops.c
test_bits.c
test_blackhole_dev.c
test_bpf.c	net: remove skb->vlan_present	2022-11-11 18:18:05 -08:00
test_debug_virtual.c
test_dynamic_debug.c	dyndbg: test DECLARE_DYNDBG_CLASSMAP, sysfs nodes	2022-09-07 17:04:49 +02:00
test_firmware.c	test_firmware: Use kstrtobool() instead of strtobool()	2023-01-20 14:09:47 +01:00
test_fprobe.c	treewide: use get_random_u32_{above,below}() instead of manual loop	2022-11-18 02:15:22 +01:00
test_fpu.c
test_free_pages.c	lib/test_free_pages.c: pass a pointer to virt_to_page()	2022-07-17 17:14:36 -07:00
test_hash.c
test_hexdump.c	treewide: use get_random_u32_inclusive() when possible	2022-11-18 02:18:02 +01:00
test_hmm_uapi.h	hmm-tests: add test for migrate_device_range()	2022-10-12 18:51:50 -07:00
test_hmm.c	hmm-tests: add test for migrate_device_range()	2022-10-12 18:51:50 -07:00
test_ida.c
test_kmod.c	test_kmod: stop kernel-doc warnings	2023-01-25 14:07:21 -08:00
test_kprobes.c	test_kprobes: Add recursed kprobe test case	2023-02-21 08:52:42 +09:00
test_linear_ranges.c	lib/test_linear_ranges: Use LINEAR_RANGE()	2022-11-16 13:32:32 +00:00
test_list_sort.c	treewide: use get_random_u32_below() instead of deprecated function	2022-11-18 02:15:15 +01:00
test_lockup.c	lib/test_lockup: fix kernel pointer check for separate address spaces	2022-02-25 09:36:06 +01:00
test_maple_tree.c	test_maple_tree: test modifications while iterating	2023-02-09 16:51:31 -08:00
test_memcat_p.c
test_meminit.c	lib/test_meminit: add checks for the allocation functions	2022-10-12 18:51:49 -07:00
test_min_heap.c	treewide: use get_random_u32() when possible	2022-10-11 17:42:58 -06:00
test_module.c
test_objagg.c	treewide: use get_random_bytes() when possible	2022-10-11 17:42:58 -06:00
test_parman.c
test_printf.c	mm: discard __GFP_ATOMIC	2023-02-02 22:33:13 -08:00
test_ref_tracker.c
test_rhashtable.c	Networking changes for 6.2.	2022-12-13 15:47:48 -08:00
test_scanf.c
test_sort.c
test_static_key_base.c
test_static_keys.c
test_string.c	lib/test_string.c: add strspn and strcspn tests	2022-04-29 14:38:00 -07:00
test_sysctl.c	testing: use the copyleft-next-0.3.1 SPDX tag	2022-11-08 15:44:02 +01:00
test_ubsan.c
test_user_copy.c
test_uuid.c
test_vmalloc.c	lib/test_vmalloc.c: add parameter use_huge for fix_size_alloc_test	2023-01-18 17:12:41 -08:00
test_xarray.c	XArray: Fix xas_create_range() when multi-order entry present	2022-03-28 19:25:11 -04:00
test-kstrtox.c
test-string_helpers.c	treewide: use get_random_u32_below() instead of deprecated function	2022-11-18 02:15:15 +01:00
textsearch.c
timerqueue.c
trace_readwrite.c	asm-generic/io: Add _RET_IP_ to MMIO trace for more accurate debug info	2022-11-21 22:02:10 +01:00
ts_bm.c	lib/ts_bm.c: remove redundant store to variable consumed after addition	2022-07-17 17:31:39 -07:00
ts_fsm.c
ts_kmp.c
ubsan.c	hardening updates for v6.3-rc1	2023-02-21 11:07:23 -08:00
ubsan.h	arm64: Support Clang UBSAN trap codes for better reporting	2023-02-08 15:26:58 -08:00
ucmpdi2.c
ucs2_string.c
usercopy.c	uaccess: Add speculation barrier to copy_from_user()	2023-02-21 14:45:22 -08:00
uuid.c	treewide: use get_random_bytes() when possible	2022-10-11 17:42:58 -06:00
vsprintf.c	Random number generator updates for Linux 6.2-rc1.	2022-12-12 16:22:22 -08:00
win_minmax.c	lib/win_minmax: use /* notation for regular comments	2023-01-11 16:14:21 -08:00
xarray.c	mm/huge_memory: Fix xarray node memory leak	2022-06-09 16:24:25 -04:00
xxhash.c