From: Christoph Hellwig <hch@infradead.org>
To: Atish Patra <atish.patra@wdc.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>,
Dmitriy Cherkasov <dmitriy@oss-tech.org>,
Andreas Schwab <schwab@suse.de>,
Palmer Dabbelt <palmer@sifive.com>,
Johan Hovold <johan@kernel.org>,
linux-kernel@vger.kernel.org,
Paul Walmsley <paul.walmsley@sifive.com>,
Anup Patel <anup@brainfault.org>,
linux-riscv@lists.infradead.org
Subject: Re: [PATCH v2 3/4] RISC-V: Implement nosmp commandline option.
Date: Thu, 11 Apr 2019 00:01:19 -0700 [thread overview]
Message-ID: <20190411070119.GD29422@infradead.org> (raw)
In-Reply-To: <20190410230443.15729-4-atish.patra@wdc.com>
On Wed, Apr 10, 2019 at 04:04:42PM -0700, Atish Patra wrote:
> nosmp command line option sets max_cpus to zero. No secondary harts
> will boot if this is enabled. But present cpu mask will still point to
> all possible masks.
>
> Fix present cpu mask for nosmp usecase.
>
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> ---
> arch/riscv/kernel/smpboot.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
> index eb533b5c2c8c..a8ad200581aa 100644
> --- a/arch/riscv/kernel/smpboot.c
> +++ b/arch/riscv/kernel/smpboot.c
> @@ -47,6 +47,17 @@ void __init smp_prepare_boot_cpu(void)
>
> void __init smp_prepare_cpus(unsigned int max_cpus)
> {
> + int cpuid;
> +
> + /* This covers non-smp usecase mandated by "nosmp" option */
> + if (max_cpus == 0)
> + return;
> +
> + for_each_possible_cpu(cpuid) {
> + if (cpuid == smp_processor_id())
> + continue;
> + set_cpu_present(cpuid, true);
> + }
Most other architectures seem to use init_cpu_present() here.
Otherwise this looks fine to me.
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next prev parent reply other threads:[~2019-04-11 7:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-10 23:04 [PATCH v2 0/4] Miscellaneous kernel command line fixes Atish Patra
2019-04-10 23:04 ` [PATCH v2 1/4] RISC-V: Add RISC-V specific arch_match_cpu_phys_id Atish Patra
2019-04-11 6:58 ` Christoph Hellwig
2019-04-10 23:04 ` [PATCH v2 2/4] RISC-V: Fix of_get_cpu_node usage Atish Patra
2019-04-11 6:59 ` Christoph Hellwig
2019-04-11 18:14 ` Atish Patra
2019-04-10 23:04 ` [PATCH v2 3/4] RISC-V: Implement nosmp commandline option Atish Patra
2019-04-11 7:01 ` Christoph Hellwig [this message]
2019-04-11 18:42 ` Atish Patra
2019-04-10 23:04 ` [PATCH v2 4/4] RISC-V: Support nr_cpus command line option Atish Patra
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