From patchwork Wed Mar 5 10:49:24 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Valentin Schneider X-Patchwork-Id: 14002508 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 60CB1C19F32 for ; Wed, 5 Mar 2025 11:45:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=oyuuH1Wtyfod3sQmeqjOasemMV+03bK4/IyWGgNrZfQ=; b=N1nGjqpUHEK4UnTUR0VtDLWljH Cr39F4pQE21M1/s6fluleGdDxId6Vk6Ea3MfIM3tTuXf5geQCsSyixDZGjkm0Gj9v+qGB0k9v9ruL x8PKeX2FLV2ezRz7klMT7GbasFxImr265I8ysxn3ApD3c73LYTcDL/PoGymvyDC0JppH++/cFOL6k fM9R4IKyz6m5t0XB6JqfaGXn5th1CS5ZqzPLHw5DzxUHnr8eZSdHhdRVmlmqoHQdUVwp3wtAsP+Nx 586jN/c3o5TASNtyfDKzoxuFKLuk1Uf0/3mCiSJG2ZFz2CN8PqqB/JzPEZNxG6AxKOWLX7G4BT5iw Bs7u8GwQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tpnBH-00000007u6e-3Dcy; Wed, 05 Mar 2025 11:44:55 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tpmKJ-00000007kB2-2ObI for linux-arm-kernel@lists.infradead.org; Wed, 05 Mar 2025 10:50:13 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741171809; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=oyuuH1Wtyfod3sQmeqjOasemMV+03bK4/IyWGgNrZfQ=; b=MfHQXWJsW/FseJETHpxfV0KaShSPXOR1B99Q9Jg+V4vojXXJKB5v4jVEpWKqaSzn0iB/xe 013W3G9QHJtQwhSmDCmDGfOCR6Ygg1yuLT8HhsoKMK05ErxQv2mPXzBwooHmo+OCd4FIoD 36trP3EhMBQKtgm6bHc8oamYARg49fc= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-106-z4bOYVHsNB2mtiR9Wm03Uw-1; Wed, 05 Mar 2025 05:49:58 -0500 X-MC-Unique: z4bOYVHsNB2mtiR9Wm03Uw-1 X-Mimecast-MFC-AGG-ID: z4bOYVHsNB2mtiR9Wm03Uw_1741171796 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 57A8D1955DCD; Wed, 5 Mar 2025 10:49:55 +0000 (UTC) Received: from vschneid-thinkpadt14sgen2i.remote.csb (unknown [10.44.32.95]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CAE451954B32; Wed, 5 Mar 2025 10:49:48 +0000 (UTC) From: Valentin Schneider To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Mike Galbraith , Peter Collingbourne , Mark Rutland , Thomas Gleixner , Neeraj Upadhyay , Thiago Jung Bauermann , Mark Brown , Kristina Martsenko , Sebastian Andrzej Siewior , Petr Tesarik , Jinjie Ruan , Juri Lelli , Phil Auld Subject: [PATCH 0/1] arm64: enable PREEMPT_LAZY Date: Wed, 5 Mar 2025 11:49:24 +0100 Message-ID: <20250305104925.189198-1-vschneid@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250305_025011_682710_2B759CF1 X-CRM114-Status: GOOD ( 10.76 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hey folks, This is a resubmission of Mark's patch [1]. I didn't end up changing anything other than fluffing up the changelog. I ran this under an arm64 VM, added some trace_printk's and checked that sched_switch's between runnable hackbench threads would occurr in the right conditions: o with TIF_NEED_RESCHED_LAZY set o at the tick o at do_notify_resume() o with TIF_NEED_RESCHED set [1]: https://lore.kernel.org/linux-rt-users/Z2B5y3HiLuRHPfdv@J2N7QTR9R3.cambridge.arm.com/ Cheers, Valentin Mark Rutland (1): arm64: enable PREEMPT_LAZY arch/arm64/Kconfig | 1 + arch/arm64/include/asm/thread_info.h | 16 +++++++++------- arch/arm64/kernel/entry-common.c | 2 +- 3 files changed, 11 insertions(+), 8 deletions(-) Reviewed-by: Sebastian Andrzej Siewior --- 2.43.0