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From: Greg Kurz <groug@kaod.org>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>
Cc: qemu-devel@nongnu.org, Peter Maydell <peter.maydell@linaro.org>,
	Eduardo Habkost <ehabkost@redhat.com>,
	kvm@vger.kernel.org, Juan Quintela <quintela@redhat.com>,
	qemu-ppc@nongnu.org, Marcelo Tosatti <mtosatti@redhat.com>,
	"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	qemu-arm@nongnu.org, Alistair Francis <alistair.francis@wdc.com>,
	Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	David Gibson <david@gibson.dropbear.id.au>,
	Richard Henderson <rth@twiddle.net>
Subject: Re: [PATCH 04/15] hw/ppc/spapr_rtas: Restrict variables scope to single switch case
Date: Thu, 9 Jan 2020 18:43:49 +0100
Message-ID: <20200109184349.1aefa074@bahia.lan> (raw)
In-Reply-To: <20200109152133.23649-5-philmd@redhat.com>

On Thu,  9 Jan 2020 16:21:22 +0100
Philippe Mathieu-Daudé <philmd@redhat.com> wrote:

> We only access these variables in RTAS_SYSPARM_SPLPAR_CHARACTERISTICS
> case, restrict their scope to avoid unnecessary initialization.
> 

I guess a decent compiler can be smart enough detect that the initialization
isn't needed outside of the RTAS_SYSPARM_SPLPAR_CHARACTERISTICS branch...
Anyway, reducing scope isn't bad. The only hitch I could see is that some
people do prefer to have all variables declared upfront, but there's a nested
param_val variable already so I guess it's okay.

> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  hw/ppc/spapr_rtas.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index 6f06e9d7fe..7237e5ebf2 100644
> --- a/hw/ppc/spapr_rtas.c
> +++ b/hw/ppc/spapr_rtas.c
> @@ -267,8 +267,6 @@ static void rtas_ibm_get_system_parameter(PowerPCCPU *cpu,
>                                            uint32_t nret, target_ulong rets)
>  {
>      PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> -    MachineState *ms = MACHINE(spapr);
> -    unsigned int max_cpus = ms->smp.max_cpus;
>      target_ulong parameter = rtas_ld(args, 0);
>      target_ulong buffer = rtas_ld(args, 1);
>      target_ulong length = rtas_ld(args, 2);
> @@ -276,6 +274,8 @@ static void rtas_ibm_get_system_parameter(PowerPCCPU *cpu,
>  
>      switch (parameter) {
>      case RTAS_SYSPARM_SPLPAR_CHARACTERISTICS: {
> +        MachineState *ms = MACHINE(spapr);
> +        unsigned int max_cpus = ms->smp.max_cpus;

The max_cpus variable used to be a global. Now that it got moved
below ms->smp, I'm not sure it's worth keeping it IMHO. What about
dropping it completely and do:

        char *param_val = g_strdup_printf("MaxEntCap=%d,"
                                          "DesMem=%" PRIu64 ","
                                          "DesProcs=%d,"
                                          "MaxPlatProcs=%d",
                                          ms->smp.max_cpus,
                                          current_machine->ram_size / MiB,
                                          ms->smp.cpus,
                                          ms->smp.max_cpus);

And maybe insert an empty line between the declaration of param_val
and the code for a better readability ?

>          char *param_val = g_strdup_printf("MaxEntCap=%d,"
>                                            "DesMem=%" PRIu64 ","
>                                            "DesProcs=%d,"


  reply index

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-09 15:21 [PATCH 00/15] Replace current_machine by qdev_get_machine() Philippe Mathieu-Daudé
2020-01-09 15:21 ` [PATCH 01/15] target/arm/kvm: Use CPUState::kvm_state in kvm_arm_pmu_supported() Philippe Mathieu-Daudé
2020-01-10  9:59   ` Alistair Francis
2020-01-09 15:21 ` [PATCH 02/15] hw/ppc/spapr_rtas: Use local MachineState variable Philippe Mathieu-Daudé
2020-01-09 17:13   ` Greg Kurz
2020-01-13  1:11   ` David Gibson
2020-01-09 15:21 ` [PATCH 03/15] hw/ppc/spapr_rtas: Access MachineState via SpaprMachineState argument Philippe Mathieu-Daudé
2020-01-09 17:13   ` Greg Kurz
2020-01-13  1:11   ` David Gibson
2020-01-09 15:21 ` [PATCH 04/15] hw/ppc/spapr_rtas: Restrict variables scope to single switch case Philippe Mathieu-Daudé
2020-01-09 17:43   ` Greg Kurz [this message]
2020-01-10  9:34     ` Philippe Mathieu-Daudé
2020-01-10  9:50       ` Greg Kurz
2020-01-10 19:18         ` Eric Blake
2020-01-13  7:16         ` David Gibson
2020-01-09 15:21 ` [PATCH 05/15] device-hotplug: Replace current_machine by qdev_get_machine() Philippe Mathieu-Daudé
2020-01-12  9:42   ` Alistair Francis
2020-01-09 15:21 ` [PATCH 06/15] migration/savevm: " Philippe Mathieu-Daudé
2020-01-09 15:52   ` Dr. David Alan Gilbert
2020-01-12  9:43   ` Alistair Francis
2020-01-14 13:27   ` Juan Quintela
2020-01-09 15:21 ` [PATCH 07/15] hw/core/machine-qmp-cmds: " Philippe Mathieu-Daudé
2020-01-12  9:44   ` Alistair Francis
2020-01-09 15:21 ` [PATCH 08/15] target/arm/monitor: " Philippe Mathieu-Daudé
2020-01-12  9:47   ` Alistair Francis
2020-01-09 15:21 ` [PATCH 09/15] device_tree: " Philippe Mathieu-Daudé
2020-01-12  9:47   ` Alistair Francis
2020-01-09 15:21 ` [PATCH 10/15] memory: " Philippe Mathieu-Daudé
2020-01-12  9:48   ` Alistair Francis
2020-01-12 13:45     ` Philippe Mathieu-Daudé
2020-01-14  2:02       ` Alistair Francis
2020-01-09 15:21 ` [PATCH 11/15] exec: " Philippe Mathieu-Daudé
2020-01-14  1:57   ` Alistair Francis
2020-01-09 15:21 ` [PATCH 12/15] accel: Introduce the current_accel() method Philippe Mathieu-Daudé
2020-01-14  1:59   ` Alistair Francis
2020-01-09 15:21 ` [PATCH 13/15] accel: Replace current_machine->accelerator by " Philippe Mathieu-Daudé
2020-01-14  1:58   ` Alistair Francis
2020-01-09 15:21 ` [PATCH 14/15] accel/accel: Replace current_machine by qdev_get_machine() Philippe Mathieu-Daudé
2020-01-14  1:59   ` Alistair Francis
2020-01-09 15:21 ` [PATCH 15/15] vl: Make current_machine a local variable Philippe Mathieu-Daudé
2020-01-14  2:00   ` Alistair Francis
2020-01-21  8:59 ` [PATCH 00/15] Replace current_machine by qdev_get_machine() Markus Armbruster

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