From: Will Deacon <will@kernel.org>
To: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: catalin.marinas@arm.com, tsbogend@alpha.franken.de,
tglx@kernel.org, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org,
kees@kernel.org, nathan@kernel.org, linusw@kernel.org,
ojeda@kernel.org, david.kaplan@amd.com, lukas.bulwahn@redhat.com,
ryan.roberts@arm.com, maz@kernel.org, timothy.hayes@arm.com,
lpieralisi@kernel.org, thuth@redhat.com,
menglong8.dong@gmail.com, oupton@kernel.org, yeoreum.yun@arm.com,
miko.lenczewski@arm.com, broonie@kernel.org,
kevin.brodsky@arm.com, james.clark@linaro.org,
yangyicong@hisilicon.com, tabba@google.com, osandov@fb.com,
arnd@arndb.de, anshuman.khandual@arm.com, david@kernel.org,
akpm@linux-foundation.org, ljs@kernel.org, dev.jain@arm.com,
yang@os.amperecomputing.com, chaitanyas.prakash@arm.com,
kprateek.nayak@amd.com, chenl311@chinatelecom.cn,
sshegde@linux.ibm.com, thorsten.blum@linux.dev,
chang.seok.bae@intel.com, tim.c.chen@linux.intel.com,
x86@kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org
Subject: Re: [PATCH v3 12/12] arm64: Add HOTPLUG_PARALLEL support for secondary CPUs
Date: Tue, 7 Jul 2026 11:30:45 +0100 [thread overview]
Message-ID: <akzVVSWMOomcw1pG@willie-the-truck> (raw)
In-Reply-To: <bddf7a68-7789-4ec2-819c-aaaee8173c70@huawei.com>
On Tue, Jul 07, 2026 at 12:00:12PM +0800, Jinjie Ruan wrote:
>
>
> On 6/24/2026 5:25 PM, Jinjie Ruan wrote:
> > Support for parallel secondary CPU bringup is already utilized by x86,
> > MIPS and RISC-V. This patch brings this capability to the arm64
> > architecture.
> >
> > To fully enable HOTPLUG_PARALLEL, this patch implements an arm64-specific
> > arch_cpuhp_init_parallel_bringup() handler.
> >
> > In parallel bringup, early `set_cpu_present(cpu, 0)` inside
> > cpu_die_early() removes the secondary CPU prematurely, causing the primary
> > CPU's second-stage cpuhp_bringup_mask() sweep to skip it and drop
> > failure logs.
>
>
> Hi, Will,
>
> In parallel bringup, cpu_die_early() calls set_cpu_present(cpu, 0),
> which removes the failing secondary CPU from the mask. This causes the
> primary CPU's cpuhp_bringup_mask() sweep to skip it and drop any failure
> log.
>
> Have you seen this before, and what do you think about the fix?
Yes, I tried to fix this here:
https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/commit/?h=cpu-hotplug&id=7e1e4144a54a80e05017e56e0e28e759bd790daa
by moving the manipulation of the present mask to
arch_cpuhp_cleanup_kick_cpu(). I'd just like to nail down the RCU and
cpufeature issues before posting that lot.
Will
next prev parent reply other threads:[~2026-07-07 10:31 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-24 9:25 [PATCH v3 00/12] arm64: Add HOTPLUG_PARALLEL support for secondary CPUs Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 01/12] cpu/hotplug: Introduce CONFIG_HOTPLUG_PARALLEL_SMT Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 02/12] cpu/hotplug: Propagate bring-up status to arch_cpuhp_cleanup_kick_cpu() Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 03/12] arm64: smp: Tidy up smp_prepare_cpus() Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 04/12] arm64: smp: Tidy up cpuinfo init and cpufeature updates Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 05/12] arm64: smp: Defer RCU registration during secondary CPU bringup Jinjie Ruan
2026-07-06 17:39 ` Will Deacon
2026-07-07 3:02 ` Jinjie Ruan
2026-07-07 10:27 ` Will Deacon
2026-06-24 9:25 ` [PATCH v3 06/12] arm64: smp: Use generic HOTPLUG_SPLIT_STARTUP machinery for CPU onlining Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 07/12] arm64: cpu_ops: Make 'cpu_operations' pointer global instead of per-cpu Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 08/12] arm64: cpu_ops: Introduce get_secondary_cpu_ops() Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 09/12] arm64: cpufeature: Ensure atomic updates to system_cpucaps bitmap Jinjie Ruan
2026-07-06 17:40 ` Will Deacon
2026-07-07 3:24 ` Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 10/12] arm64: smp: Pass CPU ID to update_cpu_boot_status() Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 11/12] arm64: smp: Rework early boot data into per-CPU arrays Jinjie Ruan
2026-06-24 9:25 ` [PATCH v3 12/12] arm64: Add HOTPLUG_PARALLEL support for secondary CPUs Jinjie Ruan
2026-07-07 4:00 ` Jinjie Ruan
2026-07-07 10:30 ` Will Deacon [this message]
2026-06-24 12:16 ` [PATCH v3 00/12] " Will Deacon
2026-06-24 14:59 ` Borislav Petkov
2026-06-25 1:34 ` Jinjie Ruan
2026-07-06 17:39 ` Will Deacon
2026-07-07 8:14 ` Jinjie Ruan
2026-07-07 10:37 ` Will Deacon
2026-06-29 4:04 ` Shrikanth Hegde
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