From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: richard clark <richard.xnu.clark@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Marc Zyngier <maz@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
will@kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: Will smp_call_function_single(cpu, ...) broadcast IPI to all other cpus?
Date: Fri, 28 Jun 2024 14:13:49 +0100 [thread overview]
Message-ID: <Zn63DQhf9nMLooVw@shell.armlinux.org.uk> (raw)
In-Reply-To: <CAJNi4rMeDgDJbN0jjPguU_v5uoscJJN=5bZaShXpu7Q8X60hcg@mail.gmail.com>
On Fri, Jun 28, 2024 at 06:21:25PM +0800, richard clark wrote:
> The output is:
>
> insmod-1746 [000] dn.h1.. 928.400039: ipi_raise:
> target_mask=00000000,000000ffe (Function call interrupts)
> insmod-1746 [000] dn.h2.. 928.400042: <stack trace>
> => trace_event_raw_event_ipi_raise
> => smp_cross_call
> => arch_send_call_function_single_ipi
> => send_call_function_single_ipi
I'm not sure whether the above is misproperly pasted or not, but if it
is correct, it shows a problem.
We can see from the first line that the target mask covers CPUs 1..11.
However, the call chain is for arch_send_call_function_single_ipi(),
which does:
smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC);
and cpumask_of(cpu) should only ever contain a single bit, and not
multiple bits which the output above suggests it does!
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
next prev parent reply other threads:[~2024-06-28 13:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-27 9:26 Will smp_call_function_single(cpu, ...) broadcast IPI to all other cpus? richard clark
2024-06-27 10:38 ` Marc Zyngier
2024-06-27 14:12 ` Steven Rostedt
2024-06-28 1:57 ` richard clark
2024-06-28 10:21 ` richard clark
2024-06-28 12:41 ` Steven Rostedt
2024-06-29 5:41 ` richard clark
2024-06-28 13:13 ` Russell King (Oracle) [this message]
2024-06-29 5:38 ` richard clark
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