kallsyms: unroll 24-bit sequence reconstruction in get_symbol_seq()

kallsyms_seqs_of_names[] stores 3-byte big-endian sequence indices that
map alphabetical symbol positions to address-ordered symbol records. 
Currently, get_symbol_seq() reconstructs each 24-bit integer using a
3-iteration for-loop that shifts and bitwise-ORs each byte sequentially. 
During binary search in kallsyms_lookup_names() and duplicate boundary
scans, this loop introduces branch and loop overhead on the hot lookup
path.

Mark get_symbol_seq() as static inline and unroll the 3-byte extraction
into direct byte shifts: (p[0] << 16) | (p[1] << 8) | p[2].  This
eliminates loop induction variable maintenance and allows the compiler to
generate direct loads and constant shifts.

Link: https://lore.kernel.org/20260929-ksyms-tune-v7-3-be568ceef41e@gmail.com
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Andrey Grodzovsky <andrey.grodzovsky@crowdstrike.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: David Laight <david.laight.linux@gmail.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>

0 files changed, 0 insertions, 0 deletions