From: Jinjie Ruan <ruanjinjie@huawei.com>
To: Will Deacon <will@kernel.org>, <linux-arm-kernel@lists.infradead.org>
Cc: <linux-kernel@vger.kernel.org>, Thomas Gleixner <tglx@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Borislav Petkov <bp@alien8.de>,
Lorenzo Pieralisi <lpieralisi@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
David Woodhouse <dwmw@amazon.co.uk>,
Peter Zijlstra <peterz@infradead.org>,
Marc Zyngier <maz@kernel.org>
Subject: Re: [PATCH 08/19] arm64: smp: Don't bother printing the I-cache policy for each CPU
Date: Tue, 8 Sep 2026 16:33:18 +0800 [thread overview]
Message-ID: <87672067-8822-4f76-8e52-8b8767a28e6f@huawei.com> (raw)
In-Reply-To: <20260907164024.17164-9-will@kernel.org>
在 2026/9/8 0:40, Will Deacon 写道:
> The I-cache policy isn't particularly interesting but printing it early
> can result in unnecessary serialisation of onlining CPUs.
>
> Remove the pointless print.
>
> Signed-off-by: Will Deacon <will@kernel.org>
> ---
> arch/arm64/kernel/cpuinfo.c | 16 ----------------
> 1 file changed, 16 deletions(-)
>
> diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
> index b423301a13cc..6dbea3a8bb23 100644
> --- a/arch/arm64/kernel/cpuinfo.c
> +++ b/arch/arm64/kernel/cpuinfo.c
> @@ -31,19 +31,6 @@
> * values depending on configuration at or after reset.
> */
> DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
> -
> -static inline const char *icache_policy_str(int l1ip)
> -{
> - switch (l1ip) {
> - case CTR_EL0_L1Ip_VIPT:
> - return "VIPT";
> - case CTR_EL0_L1Ip_PIPT:
> - return "PIPT";
> - default:
> - return "RESERVED/UNKNOWN";
> - }
> -}
> -
> unsigned long __icache_flags;
>
> static const char *const hwcap_str[] = {
> @@ -424,7 +411,6 @@ device_initcall(cpuinfo_regs_init);
>
> static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
> {
> - unsigned int cpu = smp_processor_id();
> u32 l1ip = CTR_L1IP(info->reg_ctr);
>
> switch (l1ip) {
> @@ -436,8 +422,6 @@ static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
> set_bit(ICACHEF_ALIASING, &__icache_flags);
> break;
> }
> -
> - pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str(l1ip), cpu);
As we need to defer RCU registration during secondary CPU bringup, so we
should avoid unnecessary early print during secondary CPU bringup, which
will trigger a false-positive lockdep"suspicious RCU usage" splat during
early lock acquisitions as commit ce3d31ad3cac ("arm64/smp: Move
rcu_cpu_starting() earlier") pointed out.
LGTM
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
> }
>
> static void __cpuinfo_store_cpu_32bit(struct cpuinfo_32bit *info)
next prev parent reply other threads:[~2026-09-08 8:33 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-07 16:40 [PATCH 00/19] arm64: Implement parallel CPU onlining with PSCI v0.2+ Will Deacon
2026-09-07 16:40 ` [PATCH 01/19] cpu/hotplug: Clean up cmpxchg() logic in cpuhp_can_boot_ap() Will Deacon
2026-09-08 2:55 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 02/19] cpu/hotplug: Avoid trying to bring up CPUs that are already online Will Deacon
2026-09-08 3:13 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 03/19] cpu/hotplug: Avoid busy-polling on archs where cpu_relax() is a no-op Will Deacon
2026-09-08 4:00 ` Jinjie Ruan
2026-09-11 7:16 ` Jinjie Ruan
2026-09-11 12:57 ` Will Deacon
2026-09-07 16:40 ` [PATCH 04/19] cpu/hotplug: Propagate bring-up status to arch_cpuhp_cleanup_kick_cpu() Will Deacon
2026-09-08 4:05 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 05/19] arm64: smp: Tidy up smp_prepare_cpus() Will Deacon
2026-09-08 7:35 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 06/19] arm64: smp: Tidy up cpuinfo init and cpufeature updates Will Deacon
2026-09-08 7:53 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 07/19] arm64: smp: Defer update of secondary CPU capabilities Will Deacon
2026-09-08 8:20 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 08/19] arm64: smp: Don't bother printing the I-cache policy for each CPU Will Deacon
2026-09-08 8:33 ` Jinjie Ruan [this message]
2026-09-07 16:40 ` [PATCH 09/19] arm64: smp: Defer RCU registration during secondary CPU bringup Will Deacon
2026-09-08 8:55 ` Jinjie Ruan
2026-09-08 10:19 ` Will Deacon
2026-09-08 11:25 ` Jinjie Ruan
2026-09-09 12:36 ` Will Deacon
2026-09-10 2:47 ` Jinjie Ruan
2026-09-11 12:52 ` Will Deacon
2026-09-07 16:40 ` [PATCH 10/19] arm64: smp: Use generic HOTPLUG_CORE_SYNC_FULL machinery for CPU onlining Will Deacon
2026-09-08 9:01 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 11/19] arm64: smp: Use generic HOTPLUG_SPLIT_STARTUP " Will Deacon
2026-09-08 9:10 ` Jinjie Ruan
2026-09-08 11:35 ` Jinjie Ruan
2026-09-11 12:55 ` Will Deacon
2026-09-07 16:40 ` [PATCH 12/19] arm64: cpu_ops: Make 'cpu_operations' pointer global instead of per-cpu Will Deacon
2026-09-08 11:32 ` Jinjie Ruan
2026-09-11 12:55 ` Will Deacon
2026-09-07 16:40 ` [PATCH 13/19] arm64: cpu_ops: Introduce get_secondary_cpu_ops() Will Deacon
2026-09-08 11:56 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 14/19] firmware/psci: Cache PSCI v0.2+ version number to avoid redundant SMCs Will Deacon
2026-09-08 11:57 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 15/19] firmware/psci: Extend ->cpu_on() callback to take an additional argument Will Deacon
2026-09-08 12:05 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 16/19] arm64: cpu_ops: Expose optional argument to target cpu in ->cpu_boot() Will Deacon
2026-09-08 12:12 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 17/19] arm64: smp: Pass secondary CPU boot parameters via firmware if possible Will Deacon
2026-09-08 12:16 ` Jinjie Ruan
2026-09-07 16:40 ` [PATCH 18/19] arm64: smp: Use generic HOTPLUG_PARALLEL machinery for CPU onlining Will Deacon
2026-09-08 13:05 ` Jinjie Ruan
2026-09-11 12:56 ` Will Deacon
2026-09-07 16:40 ` [PATCH 19/19] arm64: smp: Harden parallel CPU bringup against broken PSCI firmware Will Deacon
2026-09-08 13:36 ` Will Deacon
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