From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 84BC8320A22; Fri, 20 Feb 2026 09:28:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771579681; cv=none; b=PsTNAgMZKBGOOQrjzq+D+fUnbvg/5CR+1YHTIqxKkA9gwtneUi9pjhI48+Jpef/9B+jNb7rKLK/S6woa2lOhwK4cdjc8W2RvbVfWVNUF9p1rZ3MKGOANuYQ4GSrz1zVBUmXQcfZIRG42Nkv4UZ1K5//NEaKgZG8uIzi/xBhrsJw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771579681; c=relaxed/simple; bh=nmlph+5TWjJa0sHPU1ah7ms/7375H0UUdoBhmRt0/vM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=A2Ndp6ZWL/1AitHbby7WC285FXVfRMZk8LHMCVXWidbC27reNsTN4al/whYW/yrxF65LI3xIKj1ZJHL5V8TzZb1awbqnMcNK8dGF2KJQ7j1CgQvYxM0/70KoTgmnKN0G1UCYNyMTcXUzRvyyAn7VoOGzVHKjPpJG4CUHwGkaDGk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EQEDWYJM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EQEDWYJM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29E53C116D0; Fri, 20 Feb 2026 09:27:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771579681; bh=nmlph+5TWjJa0sHPU1ah7ms/7375H0UUdoBhmRt0/vM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EQEDWYJM8jermjpwnybPt56VLRR5jNeGmSaE8MsYD5T8dczHcIXHts+owh9fueUGX f6YMIT/Y4v1LoPI6Hmgy10ShyHpfEtFND57kJPWdK4NXBdODdqn2l2hLv1Akm0H6mY lKTeOZSKQSI1gkacgnbRuduE58kevHFi+W2SNmDZq/VyGAhCmx4cvuK0EuVbPUr/ry zIkuHWHmpbGvZDVaLGlbc+fo8+CbBxBLYg95xOTO4V0lraWNlaUXyJgSln7NAj36me iBR48SFhwvwXd7VqSKX7HzHKkiF0/WmUQRTrskur/tnb8awG0Bgn/fY3WlvMrchY20 eWwHB6qqRMDXA== From: Jisheng Zhang To: Catalin Marinas , Will Deacon , Arnd Bergmann , Thomas Gleixner , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Guo Ren Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-riscv@lists.infradead.org, linux-csky@vger.kernel.org Subject: [PATCH 2/3] genirq: use runtime constant to optimize handle_arch_irq access Date: Fri, 20 Feb 2026 17:09:21 +0800 Message-ID: <20260220090922.1506-3-jszhang@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260220090922.1506-1-jszhang@kernel.org> References: <20260220090922.1506-1-jszhang@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Currently, on GENERIC_IRQ_MULTI_HANDLER platforms, the handle_arch_irq is a pointer which is set during booting, and every irq processing needs to access it, so it sits in hot code path. We can use the runtime constant mechanism which was introduced by Linus to speed up its accessing. Tested on Sipeed Lichee Pi 4A (riscv64) board, the perf sched benchmark is improved by ~5.8% Signed-off-by: Jisheng Zhang --- include/linux/irq.h | 4 +++- kernel/irq/handle.c | 8 +++++--- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/include/linux/irq.h b/include/linux/irq.h index 951acbdb9f84..2ba4a8afb71e 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -1274,6 +1274,7 @@ void ipi_mux_process(void); int ipi_mux_create(unsigned int nr_ipi, void (*mux_send)(unsigned int cpu)); #ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER +#include /* * Registers a generic IRQ handling function as the top-level IRQ handler in * the system, which is generally the first C code called from an assembly @@ -1288,7 +1289,8 @@ int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)); * Allows interrupt handlers to find the irqchip that's been registered as the * top-level IRQ handler. */ -extern void (*handle_arch_irq)(struct pt_regs *) __ro_after_init; +extern void (*_handle_arch_irq)(struct pt_regs *) __ro_after_init; +#define handle_arch_irq runtime_const_ptr(_handle_arch_irq) asmlinkage void generic_handle_arch_irq(struct pt_regs *regs); #else #ifndef set_handle_irq diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index b7d52821837b..aac9e7b1301e 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -15,13 +15,14 @@ #include #include +#include #include #include "internals.h" #ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER -void (*handle_arch_irq)(struct pt_regs *) __ro_after_init; +void (*_handle_arch_irq)(struct pt_regs *) __ro_after_init; #endif /** @@ -270,10 +271,11 @@ irqreturn_t handle_irq_event(struct irq_desc *desc) #ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) { - if (handle_arch_irq) + if (_handle_arch_irq) return -EBUSY; - handle_arch_irq = handle_irq; + _handle_arch_irq = handle_irq; + runtime_const_init(ptr, _handle_arch_irq); return 0; } -- 2.51.0