[PATCH 0/4] entry: Move ret_from_fork() to C and inline syscall_exit_to_user_mode()
From: Charlie Jenkins
Date: Wed Jan 22 2025 - 17:57:03 EST
Similar to commit 221a164035fd ("entry: Move
syscall_enter_from_user_mode() to header file"), move
syscall_exit_to_user_mode() to the header file as well.
Testing was done with the byte-unixbench [1] syscall benchmark (which
calls getpid) and QEMU. On riscv I measured a 7.09246% improvement, on
x86 a 2.98843% improvement, on loongarch a 6.07954% improvement, and on
s390 a 11.1328% improvement.
Since this is on QEMU, I know these numbers are not perfect, but they
show a trend of general improvement across all architectures that use
the generic entry code.
[1] https://github.com/kdlucas/byte-unixbench
Signed-off-by: Charlie Jenkins <charlie@xxxxxxxxxxxx>
---
Charlie Jenkins (4):
riscv: entry: Convert ret_from_fork() to C
riscv: entry: Split ret_from_fork() into user and kernel
loongarch: entry: Migrate ret_from_fork() to C
entry: Inline syscall_exit_to_user_mode()
arch/loongarch/include/asm/switch_to.h | 8 ++++++
arch/loongarch/kernel/entry.S | 22 +++++++--------
arch/loongarch/kernel/process.c | 36 ++++++++++++++++++++----
arch/riscv/include/asm/asm-prototypes.h | 2 ++
arch/riscv/kernel/entry.S | 20 ++++++++------
arch/riscv/kernel/process.c | 21 ++++++++++++--
include/linux/entry-common.h | 43 +++++++++++++++++++++++++++--
kernel/entry/common.c | 49 +--------------------------------
8 files changed, 122 insertions(+), 79 deletions(-)
---
base-commit: ffd294d346d185b70e28b1a28abe367bbfe53c04
change-id: 20240402-riscv_optimize_entry-583843420325
--
- Charlie