mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-16 07:35:14 +00:00
28fdfda791
[ Upstream commit60443c88f3] 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> Stable-dep-of:8cc32a9bbf("kallsyms: strip LTO-only suffixes from promoted global functions") Signed-off-by: Sasha Levin <sashal@kernel.org>
31 lines
917 B
C
31 lines
917 B
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
#ifndef LINUX_KALLSYMS_INTERNAL_H_
|
|
#define LINUX_KALLSYMS_INTERNAL_H_
|
|
|
|
#include <linux/types.h>
|
|
|
|
/*
|
|
* These will be re-linked against their real values
|
|
* during the second link stage.
|
|
*/
|
|
extern const unsigned long kallsyms_addresses[] __weak;
|
|
extern const int kallsyms_offsets[] __weak;
|
|
extern const u8 kallsyms_names[] __weak;
|
|
|
|
/*
|
|
* Tell the compiler that the count isn't in the small data section if the arch
|
|
* has one (eg: FRV).
|
|
*/
|
|
extern const unsigned int kallsyms_num_syms
|
|
__section(".rodata") __attribute__((weak));
|
|
|
|
extern const unsigned long kallsyms_relative_base
|
|
__section(".rodata") __attribute__((weak));
|
|
|
|
extern const char kallsyms_token_table[] __weak;
|
|
extern const u16 kallsyms_token_index[] __weak;
|
|
|
|
extern const unsigned int kallsyms_markers[] __weak;
|
|
extern const unsigned int kallsyms_seqs_of_names[] __weak;
|
|
|
|
#endif // LINUX_KALLSYMS_INTERNAL_H_
|