From: Peter Zijlstra <peterz@infradead.org>
To: Eric Dumazet <edumazet@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH 0/3] x86: Use static_call for three smp_ops methods
Date: Thu, 8 Jan 2026 12:51:43 +0100 [thread overview]
Message-ID: <20260108115143.GK272712@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20251222201406.3725665-1-edumazet@google.com>
On Mon, Dec 22, 2025 at 08:14:03PM +0000, Eric Dumazet wrote:
> Busy hosts with RFS enabled can send more than 6,000,000 IPI
> per second. arch_send_call_function_single_ipi() is currently
> using an indirect call (because Xen can override the target).
>
> Indirect calls are expensive on some platforms with retpoline.
>
> This series converts three smp_ops methods to static_call
> infrastructure to remove common indirect calls.
>
> Eric Dumazet (3):
> x86/smp: Use static_call for arch_send_call_function_single_ipi()
> x86/smp: Use static_call for arch_smp_send_reschedule()
> x86/smp: Use static_call for arch_send_call_function_ipi()
>
> arch/x86/include/asm/smp.h | 23 +++++++++++++++++------
> arch/x86/kernel/smp.c | 19 +++++++++++++++++++
> arch/x86/xen/smp_hvm.c | 1 +
> arch/x86/xen/smp_pv.c | 1 +
> 4 files changed, 38 insertions(+), 6 deletions(-)
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
prev parent reply other threads:[~2026-01-08 11:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-22 20:14 Eric Dumazet
2025-12-22 20:14 ` [PATCH 1/3] x86/smp: Use static_call for arch_send_call_function_single_ipi() Eric Dumazet
2026-01-16 21:22 ` [tip: x86/core] " tip-bot2 for Eric Dumazet
2025-12-22 20:14 ` [PATCH 2/3] x86/smp: Use static_call for arch_smp_send_reschedule() Eric Dumazet
2026-01-16 21:22 ` [tip: x86/core] " tip-bot2 for Eric Dumazet
2025-12-22 20:14 ` [PATCH 3/3] x86/smp: Use static_call for arch_send_call_function_ipi() Eric Dumazet
2026-01-16 21:21 ` [tip: x86/core] " tip-bot2 for Eric Dumazet
2026-01-08 11:51 ` Peter Zijlstra [this message]
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