OpenCloudOS-Kernel/kernel
Zhen Lei 60443c88f3 kallsyms: Improve the performance of kallsyms_lookup_name()
Currently, to search for a symbol, we need to expand the symbols in
'kallsyms_names' one by one, and then use the expanded string for
comparison. It's O(n).

If we sort names in ascending order like addresses, we can also use
binary search. It's O(log(n)).

In order not to change the implementation of "/proc/kallsyms", the table
kallsyms_names[] is still stored in a one-to-one correspondence with the
address in ascending order.

Add array kallsyms_seqs_of_names[], it's indexed by the sequence number
of the sorted names, and the corresponding content is the sequence number
of the sorted addresses. For example:
Assume that the index of NameX in array kallsyms_seqs_of_names[] is 'i',
the content of kallsyms_seqs_of_names[i] is 'k', then the corresponding
address of NameX is kallsyms_addresses[k]. The offset in kallsyms_names[]
is get_symbol_offset(k).

Note that the memory usage will increase by (4 * kallsyms_num_syms)
bytes, the next two patches will reduce (1 * kallsyms_num_syms) bytes
and properly handle the case CONFIG_LTO_CLANG=y.

Performance test results: (x86)
Before:
min=234, max=10364402, avg=5206926
min=267, max=11168517, avg=5207587
After:
min=1016, max=90894, avg=7272
min=1014, max=93470, avg=7293

The average lookup performance of kallsyms_lookup_name() improved 715x.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-11-12 18:47:36 -08:00
..
bpf bpf: Fix wrong reg type conversion in release_reference() 2022-11-04 00:24:12 +01:00
cgroup cgroup fixes for v6.1-rc1 2022-10-17 18:52:43 -07:00
configs Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
debug mm: remove vmacache 2022-09-26 19:46:18 -07:00
dma - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
entry entry: kmsan: introduce kmsan_unpoison_entry_regs() 2022-10-03 14:03:25 -07:00
events perf/hw_breakpoint: test: Skip the test if dependencies unmet 2022-11-02 12:22:05 +01:00
futex freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
gcov gcov: support GCC 12.1 and newer compilers 2022-10-20 21:27:22 -07:00
irq genirq: Provide generic_handle_domain_irq_safe(). 2022-09-19 15:08:38 +02:00
kcsan treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
livepatch Livepatching changes for 6.1 2022-10-10 11:36:19 -07:00
locking treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
module module: Fix NULL vs IS_ERR checking for module_get_next_page 2022-11-11 10:19:52 -08:00
power PM: hibernate: Allow hybrid sleep to work with s2idle 2022-10-25 14:53:19 +02:00
printk printk: Mark __printk percpu data ready __ro_after_init 2022-09-29 15:20:52 +02:00
rcu rcu: Keep synchronize_rcu() from enabling irqs in early boot 2022-10-20 15:34:49 -07:00
sched sched: Introduce struct balance_callback to avoid CFI mismatches 2022-10-17 16:41:25 +02:00
time treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
trace tracing: kprobe: Fix memory leak in test_gen_kprobe/kretprobe_cmd() 2022-11-04 09:10:03 +09:00
.gitignore
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels" 2022-03-31 10:36:55 +02:00
Makefile kmsan: disable instrumentation of unsupported common kernel code 2022-10-03 14:03:20 -07:00
acct.c acct: use VMA iterator instead of linked list 2022-09-26 19:46:22 -07:00
async.c
audit.c audit: use time_after to compare time 2022-08-29 19:47:03 -04:00
audit.h audit: remove selinux_audit_rule_update() declaration 2022-09-07 11:30:15 -04:00
audit_fsnotify.c audit: fix potential double free on error path from fsnotify_add_inode_mark 2022-08-22 18:50:06 -04:00
audit_tree.c audit: use fsnotify group lock helpers 2022-04-25 14:37:28 +02:00
audit_watch.c audit_init_parent(): constify path 2022-09-01 17:39:30 -04:00
auditfilter.c
auditsc.c audit/stable-6.1 PR 20221003 2022-10-04 11:05:43 -07:00
backtracetest.c
bounds.c mm: multi-gen LRU: minimal implementation 2022-09-26 19:46:09 -07:00
capability.c
cfi.c cfi: Switch to -fsanitize=kcfi 2022-09-26 10:13:13 -07:00
compat.c
configs.c
context_tracking.c MAINTAINERS: Add Paul as context tracking maintainer 2022-07-05 13:33:00 -07:00
cpu.c Intel Trust Domain Extensions 2022-05-23 17:51:12 -07:00
cpu_pm.c context_tracking: Take IRQ eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
crash_core.c vmcoreinfo: add kallsyms_num_syms symbol 2022-08-28 14:02:44 -07:00
crash_dump.c
cred.c
delayacct.c delayacct: support re-entrance detection of thrashing accounting 2022-09-26 19:46:07 -07:00
dma.c
exec_domain.c
exit.c - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
extable.c context_tracking: Take NMI eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
fail_function.c fail_function: fix wrong use of fei_attr_remove() 2022-09-11 21:55:11 -07:00
fork.c - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
freezer.c freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
gen_kheaders.sh kbuild: build init/built-in.a just once 2022-09-29 04:40:15 +09:00
groups.c security: Add LSM hook to setgroups() syscall 2022-07-15 18:21:49 +00:00
hung_task.c sched: Fix more TASK_state comparisons 2022-09-30 16:50:39 +02:00
iomem.c
irq_work.c irq_work: use kasan_record_aux_stack_noalloc() record callstack 2022-04-15 14:49:55 -07:00
jump_label.c jump_label: make initial NOP patching the special case 2022-06-24 09:48:55 +02:00
kallsyms.c kallsyms: Improve the performance of kallsyms_lookup_name() 2022-11-12 18:47:36 -08:00
kallsyms_internal.h kallsyms: Improve the performance of kallsyms_lookup_name() 2022-11-12 18:47:36 -08:00
kcmp.c
kcov.c kcov: kmsan: unpoison area->list in kcov_remote_area_put() 2022-10-03 14:03:23 -07:00
kexec.c panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kexec_core.c kexec: replace kmap() with kmap_local_page() 2022-09-11 21:55:08 -07:00
kexec_elf.c
kexec_file.c panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kexec_internal.h panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kheaders.c
kmod.c
kprobes.c kprobe: reverse kp->flags when arm_kprobe failed 2022-11-04 08:49:31 +09:00
ksysfs.c kexec: turn all kexec_mutex acquisitions into trylocks 2022-09-11 21:55:06 -07:00
kthread.c signal: break out of wait loops on kthread_stop() 2022-10-09 16:01:59 -07:00
latencytop.c latencytop: use the last element of latency_record of system 2022-09-11 21:55:12 -07:00
module_signature.c
notifier.c notifier: Add blocking/atomic_notifier_chain_register_unique_prio() 2022-05-19 19:30:30 +02:00
nsproxy.c Revert "fs/exec: allow to unshare a time namespace on vfork+exec" 2022-09-13 10:38:43 -07:00
padata.c
panic.c kernel/panic: Drop unblank_screen call 2022-09-01 16:55:35 +02:00
params.c kernel/params.c: defer most of param_sysfs_init() to late_initcall time 2022-11-11 10:19:52 -08:00
pid.c gfs2: Add glockfd debugfs file 2022-06-29 13:07:16 +02:00
pid_namespace.c kernel: pid_namespace: use NULL instead of using plain integer as pointer 2022-04-29 14:38:00 -07:00
profile.c kernel/profile.c: simplify duplicated code in profile_setup() 2022-09-11 21:55:12 -07:00
ptrace.c freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
range.c
reboot.c kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode 2022-10-04 15:59:36 +02:00
regset.c
relay.c relay: use kvcalloc to alloc page array in relay_alloc_page_array 2022-10-03 14:21:43 -07:00
resource.c resource: Introduce alloc_free_mem_region() 2022-07-21 17:19:25 -07:00
resource_kunit.c
rseq.c rseq: Kill process when unknown flags are encountered in ABI structures 2022-08-01 15:21:42 +02:00
scftorture.c scftorture: Fix distribution of short handler delays 2022-04-11 17:07:29 -07:00
scs.c kasan, vmalloc: only tag normal vmalloc allocations 2022-03-24 19:06:48 -07:00
seccomp.c seccomp: Add wait_killable semantic to seccomp user notifier 2022-05-03 14:11:58 -07:00
signal.c Scheduler changes for v6.1: 2022-10-10 09:10:28 -07:00
smp.c bitmap patches for v6.1-rc1 2022-10-10 12:49:34 -07:00
smpboot.c smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death 2022-09-11 21:55:10 -07:00
smpboot.h
softirq.c context_tracking: Take IRQ eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
stackleak.c stackleak: add on/off stack variants 2022-05-08 01:33:09 -07:00
stacktrace.c
static_call.c static_call: Don't make __static_call_return0 static 2022-04-05 09:59:38 +02:00
static_call_inline.c static_call: Don't make __static_call_return0 static 2022-04-05 09:59:38 +02:00
stop_machine.c Scheduler changes in this cycle were: 2022-05-24 11:11:13 -07:00
sys.c Random number generator updates for Linux 6.1-rc1. 2022-10-10 10:41:21 -07:00
sys_ni.c kernel/sys_ni: add compat entry for fadvise64_64 2022-08-20 15:17:45 -07:00
sysctl-test.c kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred} 2022-09-08 16:56:45 -07:00
sysctl.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
task_work.c task_work: use try_cmpxchg in task_work_add, task_work_cancel_match and task_work_run 2022-09-11 21:55:10 -07:00
taskstats.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
torture.c
tracepoint.c tracepoint: Optimize the critical region of mutex_lock in tracepoint_module_coming() 2022-09-26 13:01:18 -04:00
tsacct.c taskstats: version 12 with thread group and exe info 2022-04-29 14:38:03 -07:00
ucount.c ucounts: Split rlimit and ucount values and max values 2022-05-18 18:24:57 -05:00
uid16.c
uid16.h
umh.c freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
up.c
user-return-notifier.c
user.c
user_namespace.c ucounts: Split rlimit and ucount values and max values 2022-10-09 16:24:05 -07:00
usermode_driver.c blob_to_mnt(): kern_unmount() is needed to undo kern_mount() 2022-05-19 23:25:47 -04:00
utsname.c
utsname_sysctl.c kernel/utsname_sysctl.c: Fix hostname polling 2022-10-23 12:01:01 -07:00
watch_queue.c This was a moderately busy cycle for documentation, but nothing all that 2022-08-02 19:24:24 -07:00
watchdog.c powerpc updates for 6.0 2022-08-06 16:38:17 -07:00
watchdog_hld.c Revert "printk: add functions to prefer direct printing" 2022-06-23 18:41:40 +02:00
workqueue.c kcfi updates for v6.1-rc1 2022-10-03 17:11:07 -07:00
workqueue_internal.h