diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2021-01-30 23:08:40 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-02-09 00:02:12 +1100 |
| commit | 2a06bf3e95cd93e3640d431960181b8e47415f33 (patch) | |
| tree | 053f9595d45c435259e0ed2e10ae78c3dc5e4833 /arch/powerpc/kernel/ptrace | |
| parent | e6f8a6c86ce7b2108c03c1cc014fdae278573df1 (diff) | |
powerpc/64: context tracking remove _TIF_NOHZ
Add context tracking to the system call handler explicitly, and remove
_TIF_NOHZ.
This improves system call performance when nohz_full is enabled. On a
POWER9, gettid scv system call cost on a nohz_full CPU improves from
1129 cycles to 1004 cycles and on a housekeeping CPU from 550 cycles
to 430 cycles.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-31-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/ptrace')
| -rw-r--r-- | arch/powerpc/kernel/ptrace/ptrace.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c index 3d44b73adb83..4f3d4ff3728c 100644 --- a/arch/powerpc/kernel/ptrace/ptrace.c +++ b/arch/powerpc/kernel/ptrace/ptrace.c @@ -262,8 +262,6 @@ long do_syscall_trace_enter(struct pt_regs *regs) { u32 flags; - user_exit(); - flags = READ_ONCE(current_thread_info()->flags) & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE); @@ -340,8 +338,6 @@ void do_syscall_trace_leave(struct pt_regs *regs) step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall_exit(regs, step); - - user_enter(); } void __init pt_regs_check(void); |