From: Thomas Gleixner <tglx@kernel.org>
To: Chuyi Zhou <zhouchuyi@bytedance.com>,
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,
bigeasy@linutronix.de, clrkwllms@kernel.org, rostedt@goodmis.org,
nadav.amit@gmail.com, vkuznets@redhat.com
Cc: linux-kernel@vger.kernel.org, Chuyi Zhou <zhouchuyi@bytedance.com>
Subject: Re: [PATCH v8 02/14] smp: Enable preemption early in smp_call_function_single()
Date: Fri, 26 Jun 2026 15:44:23 +0200 [thread overview]
Message-ID: <877bnlju14.ffs@fw13> (raw)
In-Reply-To: <20260616111127.966468-3-zhouchuyi@bytedance.com>
On Tue, Jun 16 2026 at 19:11, Chuyi Zhou wrote:
> Now smp_call_function_single() disables preemption mainly for the following
> reasons:
s/Now//
Because this describes always the current context so 'Now' is redundant.
> - To protect the per-cpu csd_data from concurrent modification by other
> tasks on the current CPU in the !wait case. For the wait case,
> synchronization is not a concern as on-stack csd is used.
Please format bullet points so that they are readable
- To protect the per-cpu csd_data from concurrent modification by
other tasks on the current CPU in the !wait case. For the wait
case, synchronization is not a concern as on-stack csd is used.
...
> - To prevent the remote online CPU from being offlined. Specifically, we
> want to ensure that no new IPIs are queued after smpcfd_dying_cpu() has
> finished.
s/we want to ensure/to ensure/
Changelogs want to be written in passive voice. See Documentation.
> Disabling preemption for the entire execution is unnecessary, especially
> csd_lock_wait() part does not require preemption protection. This patch
especially the csd_lock_wait() invocation at the end of the
execution....
s/This patch enables/Enable/
See Documentation.
next prev parent reply other threads:[~2026-06-26 13:44 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-16 11:11 [PATCH v8 00/14] Allow preemption during IPI completion waiting to improve real-time performance Chuyi Zhou
2026-06-16 11:11 ` [PATCH v8 01/14] smp: Disable preemption explicitly in __csd_lock_wait() Chuyi Zhou
2026-06-26 13:38 ` Thomas Gleixner
2026-06-16 11:11 ` [PATCH v8 02/14] smp: Enable preemption early in smp_call_function_single() Chuyi Zhou
2026-06-26 13:44 ` Thomas Gleixner [this message]
2026-06-16 11:11 ` [PATCH v8 03/14] smp: Refactor remote CPU selection in smp_call_function_any() Chuyi Zhou
2026-06-26 13:49 ` Thomas Gleixner
2026-06-16 11:11 ` [PATCH v8 04/14] smp: Use task-local IPI cpumask in smp_call_function_many_cond() Chuyi Zhou
2026-06-26 14:29 ` Thomas Gleixner
2026-06-26 15:47 ` Chuyi Zhou
2026-06-26 16:07 ` Chuyi Zhou
2026-06-26 19:07 ` Thomas Gleixner
2026-06-27 0:52 ` Chuyi Zhou
2026-06-16 11:11 ` [PATCH v8 05/14] smp: Alloc percpu csd data in smpcfd_prepare_cpu() only once Chuyi Zhou
2026-06-26 14:32 ` Thomas Gleixner
2026-06-16 11:11 ` [PATCH v8 06/14] smp: Enable preemption early in smp_call_function_many_cond() Chuyi Zhou
2026-06-26 14:40 ` Thomas Gleixner
2026-06-16 11:11 ` [PATCH v8 07/14] smp: Remove preempt_disable() from smp_call_function() Chuyi Zhou
2026-06-26 14:42 ` Thomas Gleixner
2026-06-16 11:11 ` [PATCH v8 08/14] smp: Remove preempt_disable() from on_each_cpu_cond_mask() Chuyi Zhou
2026-06-16 11:11 ` [PATCH v8 09/14] scftorture: Remove preempt_disable() in scftorture_invoke_one() Chuyi Zhou
2026-06-26 14:44 ` Thomas Gleixner
2026-06-16 11:11 ` [PATCH v8 10/14] x86/mm: Factor out flush_tlb_info initialization Chuyi Zhou
2026-06-16 13:14 ` Sebastian Andrzej Siewior
2026-06-16 11:11 ` [PATCH v8 11/14] x86/mm: Cap flush_tlb_info alignment at 64 bytes Chuyi Zhou
2026-06-16 13:20 ` Sebastian Andrzej Siewior
2026-06-16 15:36 ` Chuyi Zhou
2026-06-26 14:49 ` Thomas Gleixner
2026-06-16 11:11 ` [PATCH v8 12/14] x86/mm: Move flush_tlb_info back to the stack Chuyi Zhou
2026-06-26 14:57 ` Thomas Gleixner
2026-06-16 11:11 ` [PATCH v8 13/14] x86/kvm: Disable preemption in kvm_flush_tlb_multi() Chuyi Zhou
2026-06-16 13:46 ` Sebastian Andrzej Siewior
2026-06-16 11:11 ` [PATCH v8 14/14] x86/mm: Re-enable preemption before flush_tlb_multi() Chuyi Zhou
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