Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / mirror / Atom feed
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)



  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87672067-8822-4f76-8e52-8b8767a28e6f@huawei.com \
    --to=ruanjinjie@huawei.com \
    --cc=bp@alien8.de \
    --cc=catalin.marinas@arm.com \
    --cc=dwmw@amazon.co.uk \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lpieralisi@kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=maz@kernel.org \
    --cc=peterz@infradead.org \
    --cc=tglx@kernel.org \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox