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 4088E14F118 for ; Fri, 7 Jun 2024 06:27:22 +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=1717741644; cv=none; b=nEV4FevTUnJKXVkLbxNbXPvWqqFLUcn6VR4od/6fZ+lBoyXAPUjNmaqIhEA8rMyhqnx8XhpCNWRa6d56s6PLuNPUY/UObaCKqe/+1sCMGjlPvPe1qZVb/wdqp+P+NxEPNvKkVE7j03Z/3Af0kFaatIdWsxyx9G80gJdnNtTQ4HU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717741644; c=relaxed/simple; bh=7l34DuoF32Wc8jfFzmRvwBR/sGpFa36t+jZFou8s5R8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KZp0Q/hbnwoYO9joViFMlBEXum1qt5nRFNyX2cnoZmm2Tzv7dkxTI3jNpjQPwGhqqKKmPwYXFn0wKtzK6bh3+Uwa6rdtgoLvVmsHHoNzZG4Zaa1coMZ53y0MgQR6KKy2Z2kmu+UHc/wR1lQhsTKdHU9IWgaZb1qfBhAP8R6465g= 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=MSJxb+Xw; 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="MSJxb+Xw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1717741642; 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=7l34DuoF32Wc8jfFzmRvwBR/sGpFa36t+jZFou8s5R8=; b=MSJxb+Xw6JY/7eaMlgB27fmVutflhMwm2W8xdzgoi/yIUDZRj4pXwYQat31xcSjVue7W9l cV3RRVhMb1r0hFW1STnYs3//W9TaJKk5UVq3HMNdJwKqAipby6lKCZPa1WfiowxOfa9Tij 0lWb8FE+6ACSAdLzjNrEy2vR7a5YUhA= 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-385-toa5buPyNVOv6pbV-lg_ng-1; Fri, 07 Jun 2024 02:27:15 -0400 X-MC-Unique: toa5buPyNVOv6pbV-lg_ng-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 2E06D193586D; Fri, 7 Jun 2024 06:27:11 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.200]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 2AC4D1955F14; Fri, 7 Jun 2024 06:27:01 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 7 Jun 2024 08:25:41 +0200 (CEST) Date: Fri, 7 Jun 2024 08:25:31 +0200 From: Oleg Nesterov To: Wei Fu Cc: Sudhanva.Huruli@microsoft.com, akpm@linux-foundation.org, apais@linux.microsoft.com, axboe@kernel.dk, boqun.feng@gmail.com, brauner@kernel.org, ebiederm@xmission.com, frederic@kernel.org, j.granados@samsung.com, jiangshanlai@gmail.com, joel@joelfernandes.org, josh@joshtriplett.org, linux-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, michael.christie@oracle.com, mjguzik@gmail.com, neeraj.upadhyay@kernel.org, paulmck@kernel.org, qiang.zhang1211@gmail.com, rachelmenge@linux.microsoft.com, rcu@vger.kernel.org, rostedt@goodmis.org, weifu@microsoft.com Subject: Re: [RCU] zombie task hung in synchronize_rcu_expedited Message-ID: <20240607062531.GA30954@redhat.com> References: <20240606172848.GC22450@redhat.com> <20240607030219.2990306-1-fuweid89@gmail.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: <20240607030219.2990306-1-fuweid89@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Thanks for this info, On 06/07, Wei Fu wrote: > > All the kernels disable CONFIG_PREEMPT and PREEMPT_RCU. Ah, this can explain both soft-lockup and synchronize_rcu() hang. If my theory is correct. Can you try the patch I sent? Oleg.