From nobody Sat Dec 28 00:04:01 2024 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) (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 12E6F203709 for ; Fri, 6 Dec 2024 10:18:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.255 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733480303; cv=none; b=DWdMp9I7/YC140eBj1qCRpAH2gSwWs0lVYIh8h97UJ/4/HNcLUHLonj46ZrcyS1L/efv1BvRAalDOpwv4a3UlTMh2r5Hm95gmahTX361c6qFwxfDsszYGhHN0LF6+rA3M6xxLN5AMULE853dOo7aXe7rfDx8AUU/9lLnw4cKfDw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733480303; c=relaxed/simple; bh=4WskRhQGagi4FTzcq1gOuzQk5wCw0fW6eoTW77UW75g=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=oCeMWfdJTUBAWIXxXg2ztAVebBAs/fbxBvTPQtc3ZTW0p13qiLK8pSI2unWZ3m8et0SInGoo5x/a09Cy3QTK/ovBzXgJWmtOhofjMqNpj+2MWrHR+APwdTA442tNumNkm/BxMdUDWFAH7Kjgq08UGCLFEOROCcv3QJqhE85fuVs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.255 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.48]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Y4Rw20yXpz1V4WK; Fri, 6 Dec 2024 18:15:14 +0800 (CST) Received: from kwepemg200008.china.huawei.com (unknown [7.202.181.35]) by mail.maildlp.com (Postfix) with ESMTPS id 318F818009B; Fri, 6 Dec 2024 18:18:13 +0800 (CST) Received: from huawei.com (10.90.53.73) by kwepemg200008.china.huawei.com (7.202.181.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 6 Dec 2024 18:18:11 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH -next v5 05/22] arm64: entry: Use preempt_count() and need_resched() helper Date: Fri, 6 Dec 2024 18:17:27 +0800 Message-ID: <20241206101744.4161990-6-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241206101744.4161990-1-ruanjinjie@huawei.com> References: <20241206101744.4161990-1-ruanjinjie@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemg200008.china.huawei.com (7.202.181.35) Content-Type: text/plain; charset="utf-8" The generic entry code uses preempt_count() and need_resched() helpers to check if it is time to resched. Currently, arm64 use its own check logic, that is "READ_ONCE(current_thread_info()->preempt_count =3D=3D 0", which is equivalent to "preempt_count() =3D=3D 0 && need_resched()". In preparation for moving arm64 over to the generic entry code, use these helpers to replace arm64's own code and move it ahead. No functional changes. Signed-off-by: Jinjie Ruan --- arch/arm64/kernel/entry-common.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-com= mon.c index da68c089b74b..efd1a990d138 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -88,14 +88,6 @@ static inline bool arm64_need_resched(void) if (!need_irq_preemption()) return false; =20 - /* - * Note: thread_info::preempt_count includes both thread_info::count - * and thread_info::need_resched, and is not equivalent to - * preempt_count(). - */ - if (READ_ONCE(current_thread_info()->preempt_count) !=3D 0) - 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 @@ -141,8 +133,10 @@ static __always_inline void __exit_to_kernel_mode(stru= ct pt_regs *regs, return; } =20 - if (arm64_need_resched()) - preempt_schedule_irq(); + if (!preempt_count() && need_resched()) { + if (arm64_need_resched()) + preempt_schedule_irq(); + } =20 trace_hardirqs_on(); } else { --=20 2.34.1