From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 6727D24BC18 for ; Wed, 5 Mar 2025 14:03:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741183410; cv=none; b=Ikmg2jPOnfj4tMEZZ+9ItK8jxb8/pCyoVm8iv6SQXO73xFa10BYwt+jsCdzgYMG/IudW1v4RLsR1yN+7WbGFYd3dJUW3mClAZaasF768F8fyaYy5tdpOwokyal1ziJZtK3TNeGIXKbD+NCbY9jANVKzFc43LCEh8zAtvPLYuwk8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741183410; c=relaxed/simple; bh=sv6VA9jZbZw6WMtYHKC0o2WYuG3v8NlBMXTC63Ue7YM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AKWs9YY4LOl7OTPfwjMjbH63B6j52yM3LU5DXO2THVC0eAgV7Dagr1lrzeABA+AI/sNXzdr2WiVsA3XzisJSOoQRs1EJ/4kZGZ89qwXnhvIPGxYt0yT8+OwS7jw/OTL6FGwONa6GNJCOZg+Nfh8iwnlI9QwNyvecgkNscnToyLQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=S5QJ5AIR; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="S5QJ5AIR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741183407; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=SvisxEEy81f8Soxzl6LcxPAISbi6nfCZztRfmoSPzA4=; b=S5QJ5AIRMhcg9ENX2TeU/IjJQS2CLud7bRiIiKaWRiNRMgUn696py7bJXm4mJM2xo+15tS s3lHoWJmYE0jPR7sHUmVhTRtugb0QSMmgA8JEJzd3l7d5zGP7UDWhChxHT7QqOmLEHg6M+ s+GPPJocwg5I/lf+iwi2XxNMhGMSKv4= Received: from mx-prod-mc-05.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-379-loh_HRQfNGyVhwp5Ef8Ebw-1; Wed, 05 Mar 2025 09:03:23 -0500 X-MC-Unique: loh_HRQfNGyVhwp5Ef8Ebw-1 X-Mimecast-MFC-AGG-ID: loh_HRQfNGyVhwp5Ef8Ebw_1741183393 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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 12AE01954226; Wed, 5 Mar 2025 14:03:13 +0000 (UTC) Received: from pauld.westford.csb (unknown [10.22.65.55]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 686A41954B32; Wed, 5 Mar 2025 14:03:08 +0000 (UTC) Date: Wed, 5 Mar 2025 09:03:05 -0500 From: Phil Auld To: Valentin Schneider Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, 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 Subject: Re: [PATCH 0/1] arm64: enable PREEMPT_LAZY Message-ID: <20250305140305.GA51446@pauld.westford.csb> References: <20250305104925.189198-1-vschneid@redhat.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: <20250305104925.189198-1-vschneid@redhat.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 On Wed, Mar 05, 2025 at 11:49:24AM +0100 Valentin Schneider wrote: > 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/ > Thanks! I was looking for this the other day :) Cheers, Phil > 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(-) > > -- > 2.43.0 > --