Hyeonggon Yoo db4677b350 lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default ... commit cc6003916e upstream. In workloads where this_cpu operations are frequently performed, enabling DEBUG_PREEMPT may result in significant increase in runtime overhead due to frequent invocation of __this_cpu_preempt_check() function. This can be demonstrated through benchmarks such as hackbench where this configuration results in a 10% reduction in performance, primarily due to the added overhead within memcg charging path. Therefore, do not to enable DEBUG_PREEMPT by default and make users aware of its potential impact on performance in some workloads. hackbench-process-sockets debug_preempt no_debug_preempt Amean 1 0.4743 ( 0.00%) 0.4295 * 9.45%* Amean 4 1.4191 ( 0.00%) 1.2650 * 10.86%* Amean 7 2.2677 ( 0.00%) 2.0094 * 11.39%* Amean 12 3.6821 ( 0.00%) 3.2115 * 12.78%* Amean 21 6.6752 ( 0.00%) 5.7956 * 13.18%* Amean 30 9.6646 ( 0.00%) 8.5197 * 11.85%* Amean 48 15.3363 ( 0.00%) 13.5559 * 11.61%* Amean 79 24.8603 ( 0.00%) 22.0597 * 11.27%* Amean 96 30.1240 ( 0.00%) 26.8073 * 11.01%* Link: https://lkml.kernel.org/r/20230121033942.350387-1-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Ben Segall <bsegall@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Luiz Capitulino <luizcap@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-10-25 12:03:02 +02:00
..
842
crypto
dim	linux/dim: Do nothing if no time delta between samples	2023-05-24 17:32:31 +01:00
fonts
kunit	kunit: Fix wild-memory-access bug in kunit_free_suite_set()	2023-09-19 12:28:08 +02:00
livepatch
lz4
lzo
math
mpi	crypto: lib/mpi - avoid null pointer deref in mpi_cmp_ui()	2023-09-23 11:11:02 +02:00
pldmfw
raid6
reed_solomon
test_fortify
vdso
xz
zlib_deflate
zlib_dfltcc
zlib_inflate
zstd	zstd: Fix definition of assert()	2023-04-06 12:10:38 +02:00
.gitignore
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c
asn1_encoder.c
assoc_array.c
atomic64.c
atomic64_test.c
audit.c
base64.c
bcd.c
bch.c
bitfield_kunit.c
bitmap.c	lib/bitmap: drop optimization of bitmap_{from,to}_arr64	2023-07-19 16:21:58 +02:00
bitrev.c
bootconfig-data.S
bootconfig.c
bsearch.c
btree.c
bucket_locks.c
bug.c	cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG	2023-03-10 09:33:47 +01:00
build_OID_registry
buildid.c
bust_spinlocks.c
check_signature.c
checksum.c
clz_ctz.c	lib/clz_ctz.c: Fix __clzdi2() and __ctzdi2() for 32-bit kernels	2023-08-30 16:11:08 +02:00
clz_tab.c
cmdline.c
cmdline_kunit.c
cmpdi2.c
compat_audit.c
cpu_rmap.c	lib: cpu_rmap: Fix potential use-after-free in irq_cpu_rmap_release()	2023-06-14 11:15:22 +02:00
cpumask.c
cpumask_kunit.c
crc-ccitt.c
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: Recheck debug_objects_enabled before reporting	2023-08-11 12:08:23 +02:00
dec_and_lock.c
decompress.c
decompress_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress_unzstd.c
devmem_is_allowed.c
devres.c
digsig.c
dump_stack.c
dynamic_debug.c
dynamic_queue_limits.c
earlycpio.c
errname.c	printf: fix errname.c list	2023-03-10 09:33:27 +01:00
error-inject.c
errseq.c
extable.c
fault-inject-usercopy.c
fault-inject.c
fdt.c
fdt_addresses.c
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
find_bit.c
find_bit_benchmark.c
flex_proportions.c
fortify_kunit.c
gen_crc32table.c
gen_crc64table.c
genalloc.c
generic-radix-tree.c
glob.c
globtest.c
hexdump.c
hweight.c
idr.c	idr: fix param name in idr_alloc_cyclic() doc	2023-09-19 12:28:03 +02:00
inflate.c
interval_tree.c
interval_tree_test.c
iomap.c
iomap_copy.c
iommu-helper.c
iov_iter.c
irq_poll.c
irq_regs.c
is_signed_type_kunit.c
is_single_threaded.c
kasprintf.c
Kconfig
Kconfig.debug	lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default	2023-10-25 12:03:02 +02:00
Kconfig.kasan
Kconfig.kcsan
Kconfig.kfence
Kconfig.kgdb
Kconfig.kmsan
Kconfig.ubsan
kfifo.c
klist.c
kobject.c	kobject: Add sanity check for kset->kobj.ktype in kset_register()	2023-09-23 11:11:07 +02:00
kobject_uevent.c
kstrtox.c
kstrtox.h
libcrc32c.c
linear_ranges.c
list-test.c
list_debug.c
list_sort.c
llist.c
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	2023-02-01 08:34:34 +01:00
logic_iomem.c
logic_pio.c
lru_cache.c
lshrdi3.c
Makefile	lib/bitmap: workaround const_eval test build failure	2023-08-11 12:08:10 +02:00
maple_tree.c	maple_tree: disable mas_wr_append() when other readers are possible	2023-08-30 16:11:13 +02:00
memcat_p.c
memcpy_kunit.c
memory-notifier-error-inject.c
memregion.c
memweight.c
muldi3.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c	netlink: prevent potential spectre v1 gadgets	2023-02-01 08:34:43 +01:00
nmi_backtrace.c
notifier-error-inject.c
notifier-error-inject.h
objagg.c
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c
overflow_kunit.c
packing.c
parman.c
parser.c
pci_iomap.c
percpu-refcount.c
percpu_counter.c
percpu_test.c
plist.c
pm-notifier-error-inject.c
polynomial.c
radix-tree.c	radix tree: remove unused variable	2023-08-30 16:11:08 +02:00
random32.c
ratelimit.c
rbtree.c
rbtree_test.c
ref_tracker.c
refcount.c
rhashtable.c
sbitmap.c	sbitmap: Try each queue to wake up at least one waiter	2023-03-10 09:34:34 +01:00
scatterlist.c
seq_buf.c
sg_pool.c
sg_split.c
show_mem.c
siphash.c
slub_kunit.c
smp_processor_id.c
sort.c
stackdepot.c
stackinit_kunit.c
stmp_device.c
string.c
string_helpers.c
strncpy_from_user.c
strnlen_user.c
syscall.c
test-kstrtox.c
test-string_helpers.c
test_bitmap.c	lib/bitmap: workaround const_eval test build failure	2023-08-11 12:08:10 +02:00
test_bitops.c
test_bits.c
test_blackhole_dev.c
test_bpf.c
test_debug_virtual.c
test_dynamic_debug.c
test_firmware.c	test_firmware: return ENOMEM instead of ENOSPC on failed memory allocation	2023-08-03 10:24:19 +02:00
test_fprobe.c
test_fpu.c
test_free_pages.c
test_hash.c
test_hexdump.c
test_hmm.c
test_hmm_uapi.h
test_ida.c
test_kmod.c
test_kprobes.c
test_linear_ranges.c
test_list_sort.c
test_lockup.c
test_maple_tree.c	maple_tree: fix 32 bit mas_next testing	2023-08-03 10:23:55 +02:00
test_memcat_p.c
test_meminit.c	lib/test_meminit: fix off-by-one error in test_pages()	2023-10-15 18:32:41 +02:00
test_min_heap.c
test_module.c
test_objagg.c
test_parman.c
test_printf.c
test_ref_tracker.c
test_rhashtable.c
test_scanf.c	lib: test_scanf: Add explicit type cast to result initialization in test_number_prefix()	2023-09-19 12:28:05 +02:00
test_siphash.c
test_sort.c
test_static_key_base.c
test_static_keys.c
test_string.c
test_strscpy.c
test_sysctl.c
test_ubsan.c
test_user_copy.c
test_uuid.c
test_vmalloc.c
test_xarray.c
textsearch.c
timerqueue.c
trace_readwrite.c
ts_bm.c	lib/ts_bm: reset initial match offset for every block of text	2023-07-19 16:21:13 +02:00
ts_fsm.c
ts_kmp.c
ubsan.c	panic: Consolidate open-coded panic_on_warn checks	2023-01-24 07:24:41 +01:00
ubsan.h
ucmpdi2.c
ucs2_string.c
usercopy.c	uaccess: Add speculation barrier to copy_from_user()	2023-02-25 11:25:41 +01:00
uuid.c
vsprintf.c
win_minmax.c
xarray.c	XArray: Do not return sibling entries from xa_load()	2023-09-13 09:43:00 +02:00
xxhash.c