From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3EFB01F3BA8 for ; Mon, 10 Feb 2025 11:49:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739188143; cv=none; b=amKH+LDMG+mEz87CcR6LbNJGxoQg0mgkvRl7my1VDL/eyXv5zXu7Pc795LNdoiud3B5/2iaLl8KhoeI0QamsnqBRQfsQVdzexjztP+eJl18WFB/PT0c08u+iqlMWkDqn20JyiY7Vl0JVSqjffoSOomDNbRReNtS9JZfDxG8IMH4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739188143; c=relaxed/simple; bh=agNU50GObrX2tseacOlJ8ke2fRnXg5Qt4qTZibWZMys=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TP7pUoP5M0vRzo5bhVd0FOZlNkOg8l4TDZ4Ba94SBvayTXjzJ58nMuI73Eu8yOE4Iw0ums6BrtANTGNTprfBGUziJZ8ERM/Ak3aHm9ADF1lHRDLhfLpXERSJ+HKDH5aWh5ywIg/opo1stI0FgCA9jt8tUOBmmWDclIUw4Fdxz40= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0D1B41424; Mon, 10 Feb 2025 03:49:22 -0800 (PST) Received: from J2N7QTR9R3 (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9C4A63F5A1; Mon, 10 Feb 2025 03:48:53 -0800 (PST) Date: Mon, 10 Feb 2025 11:48:51 +0000 From: Mark Rutland To: Jinjie Ruan Cc: catalin.marinas@arm.com, will@kernel.org, oleg@redhat.com, sstabellini@kernel.org, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kees@kernel.org, wad@chromium.org, akpm@linux-foundation.org, samitolvanen@google.com, masahiroy@kernel.org, hca@linux.ibm.com, aliceryhl@google.com, rppt@kernel.org, xur@google.com, paulmck@kernel.org, arnd@arndb.de, mbenes@suse.cz, puranjay@kernel.org, pcc@google.com, ardb@kernel.org, sudeep.holla@arm.com, guohanjun@huawei.com, rafael@kernel.org, liuwei09@cestc.cn, dwmw@amazon.co.uk, Jonathan.Cameron@huawei.com, liaochang1@huawei.com, kristina.martsenko@arm.com, ptosi@google.com, broonie@kernel.org, thiago.bauermann@linaro.org, kevin.brodsky@arm.com, joey.gouly@arm.com, liuyuntao12@huawei.com, leobras@redhat.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, xen-devel@lists.xenproject.org Subject: Re: [PATCH -next v5 06/22] arm64: entry: Expand the need_irq_preemption() macro ahead Message-ID: References: <20241206101744.4161990-1-ruanjinjie@huawei.com> <20241206101744.4161990-7-ruanjinjie@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241206101744.4161990-7-ruanjinjie@huawei.com> On Fri, Dec 06, 2024 at 06:17:28PM +0800, Jinjie Ruan wrote: > The generic entry has the same logic as need_irq_preemption() > macro and use a helper function to check other resched condition. > > In preparation for moving arm64 over to the generic entry code, > check and expand need_irq_preemption() ahead and extract arm64 resched > check code to a helper function. I think this is just saying that the goal is to align the structure of the code with raw_irqentry_exit_cond_resched() from the generic entry code. It'd be a bit clearer to say that, and to do this *before* moving the call into __exit_to_kernel_mode(). Mark. > > No functional changes. > > Signed-off-by: Jinjie Ruan > --- > arch/arm64/include/asm/preempt.h | 1 + > arch/arm64/kernel/entry-common.c | 28 +++++++++++++++++----------- > 2 files changed, 18 insertions(+), 11 deletions(-) > > diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h > index 0159b625cc7f..d0f93385bd85 100644 > --- a/arch/arm64/include/asm/preempt.h > +++ b/arch/arm64/include/asm/preempt.h > @@ -85,6 +85,7 @@ static inline bool should_resched(int preempt_offset) > void preempt_schedule(void); > void preempt_schedule_notrace(void); > > +void raw_irqentry_exit_cond_resched(void); > #ifdef CONFIG_PREEMPT_DYNAMIC > > DECLARE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched); > diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c > index efd1a990d138..80b47ca02db2 100644 > --- a/arch/arm64/kernel/entry-common.c > +++ b/arch/arm64/kernel/entry-common.c > @@ -77,17 +77,10 @@ static noinstr irqentry_state_t enter_from_kernel_mode(struct pt_regs *regs) > > #ifdef CONFIG_PREEMPT_DYNAMIC > DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched); > -#define need_irq_preemption() \ > - (static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched)) > -#else > -#define need_irq_preemption() (IS_ENABLED(CONFIG_PREEMPTION)) > #endif > > static inline bool arm64_need_resched(void) > { > - if (!need_irq_preemption()) > - return false; > - > /* > * DAIF.DA are cleared at the start of IRQ/FIQ handling, and when GIC > * priority masking is used the GIC irqchip driver will clear DAIF.IF > @@ -111,6 +104,22 @@ static inline bool arm64_need_resched(void) > return true; > } > > +void raw_irqentry_exit_cond_resched(void) > +{ > +#ifdef CONFIG_PREEMPT_DYNAMIC > + if (!static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched)) > + return; > +#else > + if (!IS_ENABLED(CONFIG_PREEMPTION)) > + return; > +#endif > + > + if (!preempt_count()) { > + if (need_resched() && arm64_need_resched()) > + preempt_schedule_irq(); > + } > +} > + > /* > * Handle IRQ/context state management when exiting to kernel mode. > * After this function returns it is not safe to call regular kernel code, > @@ -133,10 +142,7 @@ static __always_inline void __exit_to_kernel_mode(struct pt_regs *regs, > return; > } > > - if (!preempt_count() && need_resched()) { > - if (arm64_need_resched()) > - preempt_schedule_irq(); > - } > + raw_irqentry_exit_cond_resched(); > > trace_hardirqs_on(); > } else { > -- > 2.34.1 >