linux/lib
Linus Torvalds 5d272dd1b3 cpumask: limit FORCE_NR_CPUS to just the UP case
Hardcoding the number of CPUs at compile time does improve code
generation, but if you get it wrong the result will be confusion.

We already limited this earlier to only "experts" (see commit
fe5759d5bf "cpumask: limit visibility of FORCE_NR_CPUS"), but with
distro kernel configs often having EXPERT enabled, that turns out to not
be much of a limit.

To quote the philosophers at Disney: "Everyone can be an expert. And
when everyone's an expert, no one will be".

There's a runtime warning if you then set nr_cpus to anything but the
forced number, but apparently that can be ignored too [1] and by then
it's pretty much too late anyway.

If we had some real way to limit this to "embedded only", maybe it would
be worth it, but let's see if anybody even notices that the option is
gone.  We need to simplify kernel configuration anyway.

Link: https://lore.kernel.org/all/20240618105036.208a8860@rorschach.local.home/ [1]
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Paul McKenney <paulmck@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-06-18 09:00:04 -07:00
..
842
crypto crypto: lib - implement library version of AES in CFB mode 2024-05-09 22:30:51 +03:00
dim lib: Allow for the DIM library to be modular 2024-05-07 16:42:45 -07:00
fonts fbdev fixes and cleanups for 6.9-rc1: 2024-03-22 10:09:08 -07:00
kunit kunit: bail out early in __kunit_test_suites_init() if there are no suites to test 2024-05-06 14:22:02 -06:00
lz4
lzo
math bitmap: introduce generic optimized bitmap_size() 2024-04-01 10:49:28 +01:00
pldmfw
raid6 lib/raid6: use CC_FLAGS_FPU for NEON CFLAGS 2024-05-19 14:36:18 -07:00
reed_solomon
test_fortify string: Remove strlcpy() 2024-01-19 11:59:11 -08:00
vdso vdso: Fix powerpc build U64_MAX undeclared error 2024-04-09 12:35:19 +02:00
xz arch: Remove Itanium (IA-64) architecture 2023-09-11 08:13:17 +00:00
zlib_deflate
zlib_dfltcc
zlib_inflate
zstd zstd: Fix array-index-out-of-bounds UBSAN warning 2023-11-14 17:12:52 -08:00
.gitignore
alloc_tag.c lib/alloc_tag: do not register sysctl interface when CONFIG_SYSCTL=n 2024-06-15 10:43:05 -07:00
argv_split.c argv_split: fix kernel-doc warnings 2023-09-19 13:21:33 -07:00
ashldi3.c
ashrdi3.c
asn1_decoder.c
asn1_encoder.c
assoc_array.c assoc_array: fix the return value in assoc_array_insert_mid_shortcut() 2024-03-12 13:09:23 -07:00
atomic64_test.c
atomic64.c
audit.c
base64.c
bcd.c
bch.c lib/bch.c: use bitrev instead of internal logic 2023-08-18 10:18:58 -07:00
bitfield_kunit.c
bitmap-str.c lib/bitmap: split-out string-related operations to a separate files 2023-10-14 20:25:22 -07:00
bitmap.c cpumask: add cpumask_weight_andnot() 2024-02-01 13:06:40 +01:00
bitrev.c
bootconfig-data.S
bootconfig.c bootconfig: Fix the kerneldoc of _xbc_exit() 2024-04-18 05:01:32 +09:00
bsearch.c
btree.c
bucket_locks.c
bug.c
build_OID_registry lib/build_OID_registry: don't mention the full path of the script in output 2024-04-25 21:07:01 -07:00
buildid.c vmlinux: Avoid weak reference to notes section 2024-05-02 19:48:26 +09:00
bust_spinlocks.c
check_signature.c
checksum_kunit.c lib: checksum: hide unused expected_csum_ipv6_magic[] 2024-04-08 11:03:05 +01:00
checksum.c
closure.c closures: closure_sync_timeout() 2024-05-08 17:29:22 -04:00
clz_ctz.c lib/clz_ctz.c: Fix __clzdi2() and __ctzdi2() for 32-bit kernels 2023-08-25 13:22:10 -07:00
clz_tab.c
cmdline_kunit.c lib/cmdline: Fix an invalid format specifier in an assertion msg 2024-02-27 15:25:56 -07:00
cmdline.c
cmpdi2.c
cmpxchg-emu.c lib: Add one-byte emulation function 2024-04-09 22:06:00 -07:00
codetag.c lib: add memory allocations report in show_mem() 2024-04-25 20:55:57 -07:00
compat_audit.c
cpu_rmap.c
cpumask_kunit.c
cpumask.c bitmap patches for v6.7 2023-11-03 07:08:36 -10:00
crc-ccitt.c lib: crc_ccitt_false() is identical to crc_itu_t() 2023-12-29 12:22:26 -08:00
crc-itu-t.c
crc-t10dif.c
crc4.c
crc7.c
crc8.c
crc16.c
crc32.c
crc32defs.h
crc32test.c
crc64-rocksoft.c
crc64.c
ctype.c
debug_info.c
debug_locks.c
debugobjects.c debugobjects: Stop accessing objects after releasing hash bucket lock 2023-11-22 10:41:46 +01:00
dec_and_lock.c
decompress_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c arch: Remove Itanium (IA-64) architecture 2023-09-11 08:13:17 +00:00
decompress_unzstd.c
decompress.c
devmem_is_allowed.c
devres.c devres: don't use "proxy" headers 2024-04-25 21:07:06 -07:00
dhry_1.c lib: dhry: use ktime_ms_delta() helper 2024-02-22 15:38:52 -08:00
dhry_2.c
dhry_run.c lib: dhry: remove unneeded <linux/mutex.h> 2024-02-22 15:38:52 -08:00
dhry.h
digsig.c
dump_stack.c dump_stack: Do not get cpu_sync for panic CPU 2024-02-07 17:23:19 +01:00
dynamic_debug.c dyndbg: fix old BUG_ON in >control parser 2024-04-30 09:20:48 +02:00
dynamic_queue_limits.c net: dqs: make struct dql more cache efficient 2024-04-15 11:19:53 -07:00
earlycpio.c
errname.c parisc: Drop the HP-UX ENOSYM and EREMOTERELEASE error codes 2023-11-25 09:43:18 +01:00
error-inject.c lib: error-inject: remove error checking for debugfs_create_dir() 2023-08-18 10:18:55 -07:00
errseq.c
extable.c
fault-inject-usercopy.c
fault-inject.c
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
find_bit.c bitmap patches for 6.10 2024-05-21 15:29:01 -07:00
flex_proportions.c flex_proportions: remove unused fprop_local_single 2024-02-22 15:38:52 -08:00
fortify_kunit.c mm/util: Swap kmemdup_array() arguments 2024-06-06 08:55:20 -07:00
fw_table.c lib/firmware_table: Provide buffer length argument to cdat_table_parse() 2024-03-13 00:03:21 -07:00
gen_crc32table.c
gen_crc64table.c
genalloc.c Devicetree include cleanups for v6.6: 2023-08-30 17:04:28 -07:00
generic-radix-tree.c lib/generic-radix-tree.c: Make nodes more reasonably sized 2024-03-13 21:22:26 -04:00
glob.c
globtest.c
group_cpus.c lib/group_cpus.c: avoid acquiring cpu hotplug lock in group_cpus_evenly 2023-12-06 16:12:46 -08:00
hashtable_test.c
hexdump.c
hweight.c
idr.c ida: Fix crash in ida_free when the bitmap is empty 2023-12-21 10:02:28 -08:00
inflate.c
interval_tree_test.c
interval_tree.c
iomap_copy.c s390: Stop using weak symbols for __iowrite64_copy() 2024-04-22 17:11:20 -03:00
iomap.c
iommu-helper.c
iov_iter.c vfs-6.9.misc 2024-03-11 09:38:17 -07:00
irq_poll.c
irq_regs.c
is_signed_type_kunit.c
is_single_threaded.c
kasprintf.c
Kconfig cpumask: limit FORCE_NR_CPUS to just the UP case 2024-06-18 09:00:04 -07:00
Kconfig.debug - A series ("kbuild: enable more warnings by default") from Arnd 2024-05-22 18:59:29 -07:00
Kconfig.kasan treewide: update LLVM Bugzilla links 2024-02-22 15:38:51 -08:00
Kconfig.kcsan
Kconfig.kfence mm/slab: remove CONFIG_SLAB from all Kconfig and Makefile 2023-12-05 11:14:40 +01:00
Kconfig.kgdb kgdb: add HAS_IOPORT dependency 2024-04-25 21:07:05 -07:00
Kconfig.kmsan mm/slab: remove CONFIG_SLAB from all Kconfig and Makefile 2023-12-05 11:14:40 +01:00
Kconfig.ubsan ubsan: Restore dependency on ARCH_HAS_UBSAN 2024-05-18 13:46:10 -07:00
kfifo.c TTY/Serial changes for 6.10-rc1 2024-05-22 11:53:02 -07:00
klist.c
kobject_uevent.c kobject: reduce uevent_sock_mutex scope 2024-02-17 16:20:41 +01:00
kobject.c Revert "kobject: Remove redundant checks for whether ktype is NULL" 2024-02-08 16:39:25 +00:00
kstrtox.c kstrtox: consistently use _tolower() 2023-08-21 13:46:25 -07:00
kstrtox.h
kunit_iov_iter.c kunit: Fix KUNIT_SUCCESS() calls in iov_iter tests 2024-05-06 14:22:02 -06:00
libcrc32c.c
linear_ranges.c
list_debug.c list: Introduce CONFIG_LIST_HARDENED 2023-08-15 14:57:25 -07:00
list_sort.c
list-test.c
llist.c llist: add llist_del_first_this() 2023-10-16 12:44:06 -04:00
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 lockdep/selftests: Use SBRM APIs for wait context tests 2023-07-26 12:29:13 +02:00
lockref.c
logic_iomem.c
logic_pio.c minmax: add in_range() macro 2023-08-24 16:20:18 -07:00
lru_cache.c
lshrdi3.c
lwq.c lib: add light-weight queuing mechanism. 2023-10-16 12:44:06 -04:00
Makefile selftests/fpu: allow building on other architectures 2024-05-19 14:36:20 -07:00
maple_tree.c maple_tree: fix mas_empty_area_rev() null pointer dereference 2024-05-05 17:28:05 -07:00
memcat_p.c
memcpy_kunit.c string_kunit: Move strtomem KUnit test to string_kunit.c 2024-04-24 09:02:34 -07:00
memory-notifier-error-inject.c
memregion.c
memweight.c
muldi3.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c netlink: add nla be16/32 types to minlen array 2024-02-22 19:01:55 -08:00
nmi_backtrace.c nmi_backtrace: allow excluding an arbitrary CPU 2023-08-18 10:19:00 -07:00
notifier-error-inject.c lib: remove error checking for debugfs_create_dir() 2023-08-18 10:18:55 -07:00
notifier-error-inject.h
objagg.c
objpool.c objpool: cache nr_possible_cpus() and avoid caching nr_cpu_ids 2024-05-01 23:18:48 +09:00
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c
overflow_kunit.c kunit/overflow: Adjust for __counted_by with DEFINE_RAW_FLEX() 2024-06-10 12:00:04 -07:00
packing.c
parman.c
parser.c
percpu_counter.c percpu_counter: extend _limited_add() to negative amounts 2023-10-18 14:34:14 -07:00
percpu_test.c
percpu-refcount.c
plist.c
pm-notifier-error-inject.c
polynomial.c
radix-tree.c radix tree: remove unused variable 2023-08-21 13:07:22 -07:00
radix-tree.h
random32.c
ratelimit.c
rbtree_test.c
rbtree.c
rcuref.c locking/atomics: Use atomic_try_cmpxchg_release() to micro-optimize rcuref_put_slowpath() 2023-10-10 10:14:27 +02:00
ref_tracker.c
refcount.c
rhashtable.c rhashtable: plumb through alloc tag 2024-04-25 20:55:57 -07:00
sbitmap.c sbitmap: use READ_ONCE to access map->word 2024-04-26 07:40:28 -06:00
scatterlist.c Fix a potential infinite loop in extract_user_to_sg() 2024-04-26 12:35:57 -07:00
seq_buf.c seq_buf: Fix kernel documentation 2024-02-15 12:17:28 -05:00
sg_pool.c
sg_split.c
siphash_kunit.c
siphash.c
slub_kunit.c mm/slub, kunit: Use inverted data to corrupt kmem cache 2024-04-04 16:08:10 +02:00
smp_processor_id.c
sort.c lib/sort: optimize heapsort with double-pop variation 2024-02-22 15:38:52 -08:00
stackdepot.c stackdepot: use gfp_nested_mask() instead of open coded masking 2024-05-19 14:40:44 -07:00
stackinit_kunit.c - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min 2024-03-14 18:03:09 -07:00
stmp_device.c
string_helpers_kunit.c string: Convert helpers selftest to KUnit 2024-03-05 01:55:28 -08:00
string_helpers.c lib/string_helpers: Add flags param to string_get_size() 2024-02-29 22:34:42 -08:00
string_kunit.c string_kunit: Move strtomem KUnit test to string_kunit.c 2024-04-24 09:02:34 -07:00
string.c string: Allow 2-argument strscpy() 2024-02-20 20:47:32 -08:00
strncpy_from_user.c
strnlen_user.c
syscall.c
test_bitmap.c bitmap patches for 6.10 2024-05-21 15:29:01 -07:00
test_bitops.c lib/test_bitops: Add benchmark test for fns() 2024-05-09 09:25:08 -07:00
test_bits.c
test_blackhole_dev.c net: blackhole_dev: fix build warning for ethh set but not used 2024-02-05 12:30:54 +00:00
test_bpf.c bpf, tests: Fix typos in comments 2024-04-16 17:22:18 +02:00
test_debug_virtual.c
test_dynamic_debug.c
test_firmware.c firmware_loader: Expand Firmware upload error codes with firmware invalid error 2023-11-24 18:09:19 -08:00
test_fprobe.c
test_fpu_glue.c selftests/fpu: allow building on other architectures 2024-05-19 14:36:20 -07:00
test_fpu_impl.c selftests/fpu: move FP code to a separate translation unit 2024-05-19 14:36:20 -07:00
test_fpu.h selftests/fpu: move FP code to a separate translation unit 2024-05-19 14:36:20 -07:00
test_free_pages.c
test_hash.c
test_hexdump.c test_hexdump: avoid string truncation warning 2024-04-25 21:07:07 -07:00
test_hmm_uapi.h
test_hmm.c lib/test_hmm.c: handle src_pfns and dst_pfns allocation failure 2024-04-25 20:55:48 -07:00
test_ida.c Quite a lot of kexec work this time around. Many singleton patches in 2024-01-09 11:46:20 -08:00
test_kmod.c lib/test_kmod: fix kernel-doc warnings 2024-02-02 10:21:26 -08:00
test_kprobes.c
test_linear_ranges.c
test_list_sort.c
test_lockup.c
test_maple_tree.c test_maple_tree: testing the cyclic allocation 2024-02-21 09:34:26 +01:00
test_memcat_p.c
test_meminit.c mm, treewide: introduce NR_PAGE_ORDERS 2024-01-08 15:27:15 -08:00
test_min_heap.c
test_module.c
test_objagg.c
test_objpool.c lib: test_objpool: make global variables static 2023-11-10 19:59:04 +09:00
test_parman.c
test_printf.c lib/vsprintf: declare no_hash_pointers in sprintf.h 2023-08-21 13:46:24 -07:00
test_ref_tracker.c
test_rhashtable.c lib/test_rhashtable: add missing MODULE_DESCRIPTION() macro 2024-06-03 18:51:18 -07:00
test_scanf.c lib: test_scanf: Add explicit type cast to result initialization in test_number_prefix() 2023-08-16 11:47:29 +02:00
test_sort.c
test_static_key_base.c
test_static_keys.c
test_sysctl.c sysctl: Remove the now superfluous sentinel elements from ctl_table array 2023-12-28 04:57:57 -08:00
test_ubsan.c ubsan: fix unused variable warning in test module 2024-04-03 14:35:57 -07:00
test_user_copy.c
test_uuid.c
test_vmalloc.c lib/test_vmalloc.c: use unsigned long constant 2024-03-04 17:01:22 -08:00
test_xarray.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
test-kstrtox.c
textsearch.c
timerqueue.c
trace_readwrite.c lib/trace_readwrite.c:: replace asm-generic/io with linux/io 2023-12-29 12:22:29 -08:00
ts_bm.c lib/ts_bm: add helper to reduce indentation and improve readability 2023-07-27 13:45:51 +02:00
ts_fsm.c
ts_kmp.c
ubsan.c ubsan: Add awareness of signed integer overflow traps 2024-04-15 17:42:43 -07:00
ubsan.h ubsan: Avoid i386 UBSAN handler crashes with Clang 2024-04-24 15:45:38 -07:00
ucmpdi2.c
ucs2_string.c lib/ucs2_string: Add UCS-2 strscpy function 2023-09-13 10:18:42 -07:00
usercopy.c usercopy: Don't use "proxy" headers 2024-05-19 16:12:38 -07:00
uuid.c
vsprintf.c wrapper for access to ->bd_partno 2024-05-02 17:48:09 -04:00
win_minmax.c
xarray.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
xxhash.c