On Fri, 2021-07-02 at 13:22 +0200, Peter Zijlstra wrote: > On Tue, Jun 22, 2021 at 05:42:49PM +0800, Zhu Lingshan wrote: > > diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c [] > > @@ -90,6 +90,27 @@ DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_aliases, *x86_pmu.pebs_aliases); > > */ > > DEFINE_STATIC_CALL_RET0(x86_pmu_guest_get_msrs, *x86_pmu.guest_get_msrs); > > > > > > +DEFINE_STATIC_CALL_RET0(x86_guest_state, *(perf_guest_cbs->state)); > > +DEFINE_STATIC_CALL_RET0(x86_guest_get_ip, *(perf_guest_cbs->get_ip)); > > +DEFINE_STATIC_CALL_RET0(x86_guest_handle_intel_pt_intr, *(perf_guest_cbs->handle_intel_pt_intr)); > > + > > +void arch_perf_update_guest_cbs(void) > > +{ > > + static_call_update(x86_guest_state, (void *)&__static_call_return0); > > + static_call_update(x86_guest_get_ip, (void *)&__static_call_return0); > > + static_call_update(x86_guest_handle_intel_pt_intr, (void *)&__static_call_return0); > > + > > + if (perf_guest_cbs && perf_guest_cbs->state) > > + static_call_update(x86_guest_state, perf_guest_cbs->state); > > + > > + if (perf_guest_cbs && perf_guest_cbs->get_ip) > > + static_call_update(x86_guest_get_ip, perf_guest_cbs->get_ip); > > + > > + if (perf_guest_cbs && perf_guest_cbs->handle_intel_pt_intr) > > + static_call_update(x86_guest_handle_intel_pt_intr, > > + perf_guest_cbs->handle_intel_pt_intr); > > +} > > Coding style wants { } on that last if(). That's just your personal preference. The coding-style document doesn't require that. It just says single statement. It's not the number of vertical lines or characters required for the statement. ---------------------------------- Do not unnecessarily use braces where a single statement will do. .. code-block:: c if (condition) action(); and .. code-block:: none if (condition) do_this(); else do_that(); This does not apply if only one branch of a conditional statement is a single statement; in the latter case use braces in both branches: