From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: tglx@kernel.org, mingo@redhat.com, luto@kernel.org,
peterz@infradead.org, paulmck@kernel.org, muchun.song@linux.dev,
bp@alien8.de, dave.hansen@linux.intel.com, pbonzini@redhat.com,
clrkwllms@kernel.org, rostedt@goodmis.org, nadav.amit@gmail.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 04/12] smp: Use task-local IPI cpumask in smp_call_function_many_cond()
Date: Wed, 3 Jun 2026 14:21:28 +0200 [thread overview]
Message-ID: <20260603122128.suObbyBe@linutronix.de> (raw)
In-Reply-To: <84866b3c-4605-46b8-ae74-639e53252e97@bytedance.com>
On 2026-06-03 19:48:50 [+0800], Chuyi Zhou wrote:
> Thanks for pointing this out.
>
> The NULL fallback in smp_call_function_many_cond() is intentional for
> cases where no task-local mask is available, such as !PREEMPT kernels or
> static/early tasks. In those cases it falls back to the per-CPU mask and
> keeps the existing preemption-disabled behavior.
Yes, I am aware of this. I just wanted to point a case where a task has
no mask associated.
Sebastian
next prev parent reply other threads:[~2026-06-03 12:21 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-28 15:13 [PATCH v6 00/12] Allow preemption during IPI completion waiting to improve real-time performance Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 01/12] smp: Disable preemption explicitly in __csd_lock_wait Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 02/12] smp: Enable preemption early in smp_call_function_single Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 03/12] smp: Refactor remote CPU selection in smp_call_function_any() Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 04/12] smp: Use task-local IPI cpumask in smp_call_function_many_cond() Chuyi Zhou
2026-06-03 10:54 ` Sebastian Andrzej Siewior
2026-06-03 11:48 ` Chuyi Zhou
2026-06-03 12:21 ` Sebastian Andrzej Siewior [this message]
2026-05-28 15:13 ` [PATCH v6 05/12] smp: Alloc percpu csd data in smpcfd_prepare_cpu() only once Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 06/12] smp: Enable preemption early in smp_call_function_many_cond Chuyi Zhou
2026-06-03 11:00 ` Sebastian Andrzej Siewior
2026-06-03 11:54 ` Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 07/12] smp: Remove preempt_disable from smp_call_function Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 08/12] smp: Remove preempt_disable from on_each_cpu_cond_mask Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 09/12] scftorture: Remove preempt_disable in scftorture_invoke_one Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 10/12] x86/mm: Move flush_tlb_info back to the stack Chuyi Zhou
2026-06-04 20:54 ` Dave Hansen
2026-06-04 21:11 ` Nadav Amit
2026-06-04 21:16 ` Dave Hansen
2026-06-04 21:21 ` Nadav Amit
2026-06-05 2:54 ` Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 11/12] x86/mm: Enable preemption during native_flush_tlb_multi Chuyi Zhou
2026-06-04 21:15 ` Dave Hansen
2026-06-05 3:36 ` Chuyi Zhou
2026-05-28 15:13 ` [PATCH v6 12/12] x86/mm: Enable preemption during flush_tlb_kernel_range Chuyi Zhou
2026-06-04 21:21 ` Dave Hansen
2026-06-05 3:51 ` Chuyi Zhou
2026-05-28 19:47 ` [PATCH v6 00/12] Allow preemption during IPI completion waiting to improve real-time performance Paul E. McKenney
2026-05-29 3:22 ` Chuyi Zhou
2026-05-29 6:41 ` Sebastian Andrzej Siewior
2026-06-03 11:02 ` Sebastian Andrzej Siewior
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