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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()
Message-ID: <20260603122128.suObbyBe@linutronix.de>
References: <20260528151338.617843-1-zhouchuyi@bytedance.com>
 <20260528151338.617843-5-zhouchuyi@bytedance.com>
 <20260603105448.2bwLH_XI@linutronix.de>
 <84866b3c-4605-46b8-ae74-639e53252e97@bytedance.com>
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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