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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 F20C7C433E0 for ; Wed, 10 Mar 2021 13:43:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEF1964FDC for ; Wed, 10 Mar 2021 13:43:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233005AbhCJNnZ (ORCPT ); Wed, 10 Mar 2021 08:43:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232712AbhCJNnM (ORCPT ); Wed, 10 Mar 2021 08:43:12 -0500 Received: from mail-pg1-x533.google.com (mail-pg1-x533.google.com [IPv6:2607:f8b0:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3076C061760 for ; Wed, 10 Mar 2021 05:43:11 -0800 (PST) Received: by mail-pg1-x533.google.com with SMTP id x29so11436535pgk.6 for ; Wed, 10 Mar 2021 05:43:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=6QbKa5CfjNQBc5FrXPhFzCcSoLKh/vfGVckzjCzVcB4=; b=egY8UYuJ73dCVQenkJirSdVtrblugbkYTcJu1ncR5T+RsEr+DVZDGhqEHW9UucCIQ0 Bno8YLlfcKOZ0p1+mfpkLpKpV8hohLpsjMbyNCF0zRn06st9pwojE6RfWB2OgY0t3cm7 mRQxpfpUmuhdmFqqe9qK+olv8yLuLPTdkdL301goyEXg5HrjxQEFHzgGs/6uitpl5HK8 Vj96cQVrx+LH5sngmBslgMjOWT2E5GXxZ7sh5od417wvVQSqTzJjortD8A0xXh++UBzH FDUN+aINAcRfg1R6Ef6c1bjicbuU3AmmItLH0hwcjti7IRPCIdeaoAdJdUnYDS1FhWUb 4MCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=6QbKa5CfjNQBc5FrXPhFzCcSoLKh/vfGVckzjCzVcB4=; b=n50U+9lL2WidjlLrEcFW7qdiIv3vOHCC2k6Q+QpExEeiL0qBTADyJwjno5FeuftSi9 +1ok7h84vIqTbjKX15PQzG3Zl0wl4hnGsbEGNMkhzJEUpkZbUDEESYzhhw/MaejoF50A mdzIyERd8cdbpxLLcw/86j50iiu3HbL6FlMN84/tKq6zk08O8QVu2Z8984W8AL1IY6yM 1VwpVxIpS0/sB6ID3yU94jzUjo9iuk0nrwZzEmVBKdfvtYMZiibUMT10z+amlJjxMAO8 lcSz4rcuHRGK1AtSYGoH5tDDYaWO1Dsn9iPf8mQWjZuLCZDSnkBNSqoM6kPz+mx/Hjhw UixQ== X-Gm-Message-State: AOAM533f6WSJi0GH9JKZ/FFm5sBNBYdPEf0MiZ5yfJZsXUslDI9MsJZt G0+AcvsFTT03QKrmCb6rN16N X-Google-Smtp-Source: ABdhPJzFIIT+ZEylH3YM4w509OWf3OLlaMjhuB47h5yPdazMWz+tPkugTITbwWnBZNdg438R2XOejg== X-Received: by 2002:a63:1b01:: with SMTP id b1mr2828631pgb.330.1615383791434; Wed, 10 Mar 2021 05:43:11 -0800 (PST) Received: from thinkpad ([103.66.79.59]) by smtp.gmail.com with ESMTPSA id 82sm16069872pfv.19.2021.03.10.05.43.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Mar 2021 05:43:10 -0800 (PST) Date: Wed, 10 Mar 2021 19:13:07 +0530 From: Manivannan Sadhasivam To: Loic Poulain Cc: hemantk@codeaurora.org, linux-arm-msm@vger.kernel.org, bbhatt@codeaurora.org Subject: Re: [PATCH] mhi: pci_generic: Remove WQ_MEM_RECLAIM flag from state workqueue Message-ID: <20210310134307.GJ30275@thinkpad> References: <1614161930-8513-1-git-send-email-loic.poulain@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1614161930-8513-1-git-send-email-loic.poulain@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Wed, Feb 24, 2021 at 11:18:50AM +0100, Loic Poulain wrote: > 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 Applied to mhi-next! Thanks, Mani > --- > drivers/bus/mhi/core/init.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c > index 32eb90f..03ddd6e 100644 > --- a/drivers/bus/mhi/core/init.c > +++ b/drivers/bus/mhi/core/init.c > @@ -890,8 +890,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl, > 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; > -- > 2.7.4 >