[AMD Official Use Only - General] Hi Ashok, > -----Original Message----- > From: Ashok Raj <ashok_raj@xxxxxxxxxxxxxxx> > Sent: Monday, January 9, 2023 5:27 PM > To: Moger, Babu <Babu.Moger@xxxxxxx> > Cc: corbet@xxxxxxx; reinette.chatre@xxxxxxxxx; tglx@xxxxxxxxxxxxx; > mingo@xxxxxxxxxx; bp@xxxxxxxxx; fenghua.yu@xxxxxxxxx; > dave.hansen@xxxxxxxxxxxxxxx; x86@xxxxxxxxxx; hpa@xxxxxxxxx; > paulmck@xxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx; quic_neeraju@xxxxxxxxxxx; > rdunlap@xxxxxxxxxxxxx; damien.lemoal@xxxxxxxxxxxxxxxxxx; > songmuchun@xxxxxxxxxxxxx; peterz@xxxxxxxxxxxxx; jpoimboe@xxxxxxxxxx; > pbonzini@xxxxxxxxxx; chang.seok.bae@xxxxxxxxx; > pawan.kumar.gupta@xxxxxxxxxxxxxxx; jmattson@xxxxxxxxxx; > daniel.sneddon@xxxxxxxxxxxxxxx; Das1, Sandipan <Sandipan.Das@xxxxxxx>; > tony.luck@xxxxxxxxx; james.morse@xxxxxxx; linux-doc@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; bagasdotme@xxxxxxxxx; eranian@xxxxxxxxxx; > christophe.leroy@xxxxxxxxxx; jarkko@xxxxxxxxxx; adrian.hunter@xxxxxxxxx; > quic_jiles@xxxxxxxxxxx; peternewman@xxxxxxxxxx; Ashok Raj > <ashok.raj@xxxxxxxxx> > Subject: Re: [PATCH v11 01/13] x86/resctrl: Replace smp_call_function_many() > with on_each_cpu_mask() > > On Mon, Jan 09, 2023 at 10:43:53AM -0600, Babu Moger wrote: > > on_each_cpu_mask() runs the function on each CPU specified by cpumask, > > which may include the local processor. > > > > Replace smp_call_function_many() with on_each_cpu_mask() to simplify > > the code. > > > > Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> > > Signed-off-by: Babu Moger <babu.moger@xxxxxxx> > > --- > > arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 11 +++------ > > arch/x86/kernel/cpu/resctrl/rdtgroup.c | 29 +++++++---------------- > > 2 files changed, 11 insertions(+), 29 deletions(-) > > > > diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c > > b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c > > index 1df0e3262bca..7eece3d2d0c3 100644 > > --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c > > +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c > > @@ -310,7 +310,6 @@ int resctrl_arch_update_domains(struct rdt_resource > *r, u32 closid) > > enum resctrl_conf_type t; > > cpumask_var_t cpu_mask; > > struct rdt_domain *d; > > - int cpu; > > u32 idx; > > > > if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) @@ -341,13 > +340,9 @@ > > int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) > > > > if (cpumask_empty(cpu_mask)) > > goto done; > > - cpu = get_cpu(); > > - /* Update resource control msr on this CPU if it's in cpu_mask. */ > > - if (cpumask_test_cpu(cpu, cpu_mask)) > > - rdt_ctrl_update(&msr_param); > > - /* Update resource control msr on other CPUs. */ > > - smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1); > > - put_cpu(); > > + > > + /* Update resource control msr on all the CPUs. */ > > + on_each_cpu_mask(cpu_mask, rdt_ctrl_update, &msr_param, 1); > > Do you require these updates to done immediately via an IPI? or can they be > done bit lazy via schedule_on_each_cpu()? I have not experimented with lazy schedule. At least I know the call update_cpu_closid_rmid should be completed immediately. Otherwise, the result might be inconsistent as the tasks(or CPUs) could be running on two different closed/rmids before it is updated on all CPUs in the domain. Thanks Babu
