From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 829D1C2BD0D for ; Mon, 10 May 2021 12:02:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66D91613DE for ; Mon, 10 May 2021 12:02:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244929AbhEJMCe (ORCPT ); Mon, 10 May 2021 08:02:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:46278 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236178AbhEJLHl (ORCPT ); Mon, 10 May 2021 07:07:41 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D44A661928; Mon, 10 May 2021 10:58:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620644325; bh=Ug7awv2zgEY/tKfDC97Qj8A85U8SPgOr1V5z8QO5iU4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0F3+ISLED7tfwQkOLvEcjp+y4wrX44dT7OIas0X/xwfoGcHnUTd/C0mG42ZeoOhT3 fPe31q3vblQkiDuFfBM0tFVexaLeKshzsiE8ZDifeg0Sj7s+BdQcepOa+8gBvphvm6 FxjE6BvY2cJngKK2ARurJMtu4mH2OixT4hAtzAQs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Loic Poulain , Bhaumik Bhatt , Manivannan Sadhasivam Subject: [PATCH 5.12 005/384] bus: mhi: pci_generic: Remove WQ_MEM_RECLAIM flag from state workqueue Date: Mon, 10 May 2021 12:16:34 +0200 Message-Id: <20210510102015.042260603@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102014.849075526@linuxfoundation.org> References: <20210510102014.849075526@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Loic Poulain commit 0fccbf0a3b690b162f53b13ed8bc442ea33437dc upstream. A recent change created a dedicated workqueue for the state-change work with WQ_HIGHPRI (no strong reason for that) and WQ_MEM_RECLAIM flags, but the state-change work (mhi_pm_st_worker) does not guarantee forward progress under memory pressure, and will even wait on various memory allocations when e.g. creating devices, loading firmware, etc... The work is then not part of a memory reclaim path... Moreover, this causes a warning in check_flush_dependency() since we end up in code that flushes a non-reclaim workqueue: [ 40.969601] workqueue: WQ_MEM_RECLAIM mhi_hiprio_wq:mhi_pm_st_worker [mhi] is flushing !WQ_MEM_RECLAIM events_highpri:flush_backlog [ 40.969612] WARNING: CPU: 4 PID: 158 at kernel/workqueue.c:2607 check_flush_dependency+0x11c/0x140 [ 40.969733] Call Trace: [ 40.969740] __flush_work+0x97/0x1d0 [ 40.969745] ? wake_up_process+0x15/0x20 [ 40.969749] ? insert_work+0x70/0x80 [ 40.969750] ? __queue_work+0x14a/0x3e0 [ 40.969753] flush_work+0x10/0x20 [ 40.969756] rollback_registered_many+0x1c9/0x510 [ 40.969759] unregister_netdevice_queue+0x94/0x120 [ 40.969761] unregister_netdev+0x1d/0x30 [ 40.969765] mhi_net_remove+0x1a/0x40 [mhi_net] [ 40.969770] mhi_driver_remove+0x124/0x250 [mhi] [ 40.969776] device_release_driver_internal+0xf0/0x1d0 [ 40.969778] device_release_driver+0x12/0x20 [ 40.969782] bus_remove_device+0xe1/0x150 [ 40.969786] device_del+0x17b/0x3e0 [ 40.969791] mhi_destroy_device+0x9a/0x100 [mhi] [ 40.969796] ? mhi_unmap_single_use_bb+0x50/0x50 [mhi] [ 40.969799] device_for_each_child+0x5e/0xa0 [ 40.969804] mhi_pm_st_worker+0x921/0xf50 [mhi] Fixes: 8f7039787687 ("bus: mhi: core: Move to using high priority workqueue") Signed-off-by: Loic Poulain Reviewed-by: Bhaumik Bhatt Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/1614161930-8513-1-git-send-email-loic.poulain@linaro.org Signed-off-by: Manivannan Sadhasivam Signed-off-by: Greg Kroah-Hartman --- drivers/bus/mhi/core/init.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/bus/mhi/core/init.c +++ b/drivers/bus/mhi/core/init.c @@ -901,8 +901,7 @@ int mhi_register_controller(struct mhi_c INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker); init_waitqueue_head(&mhi_cntrl->state_event); - mhi_cntrl->hiprio_wq = alloc_ordered_workqueue - ("mhi_hiprio_wq", WQ_MEM_RECLAIM | WQ_HIGHPRI); + mhi_cntrl->hiprio_wq = alloc_ordered_workqueue("mhi_hiprio_wq", WQ_HIGHPRI); if (!mhi_cntrl->hiprio_wq) { dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n"); ret = -ENOMEM;