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References: <20240313205622.2179659-1-mathieu.desnoyers@efficios.com> <20240313205622.2179659-2-mathieu.desnoyers@efficios.com>
In-Reply-To: <20240313205622.2179659-2-mathieu.desnoyers@efficios.com>
From: Linus Torvalds <torvalds@linuxfoundation.org>
Date: Wed, 13 Mar 2024 14:19:35 -0700
Message-ID: <CAHk-=wj5rEZFvaLgs-ZtsCX9++mFNYKox21SBfF8vrSQG4WbPA@mail.gmail.com>
Subject: Re: [RFC PATCH 1/2] smp: Implement serialized smp_call_function APIs
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Oskolkov <posk@google.com>, linux-kernel@vger.kernel.org, 
	Peter Zijlstra <peterz@infradead.org>, "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>, 
	Boqun Feng <boqun.feng@gmail.com>, Andrew Hunter <ahh@google.com>, 
	Maged Michael <maged.michael@gmail.com>, gromer@google.com, Avi Kivity <avi@scylladb.com>, 
	Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, 
	Michael Ellerman <mpe@ellerman.id.au>
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On Wed, 13 Mar 2024 at 13:56, Mathieu Desnoyers
<mathieu.desnoyers@efficios.com> wrote:
>
> Introduce serialized smp_call_function APIs to limit the number of
> concurrent smp_call_function IPIs which can be sent to a given CPU to a
> maximum of two: one broadcast and one specifically targeting the CPU.

So  honestly, with only one user, I think the serialization code
should be solidly in that one user, not in kernel/smp.c.

Also, this kind of extra complexity does require numbers to argue for it.

             Linus