From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 610B313ACC; Mon, 8 Jul 2024 08:59:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720429146; cv=none; b=KTyEbqbPSNdklpPcSBdP5k3vxbzdl6oS8CFOt5fmhdbFPObUEY2nhDjwnwlsOa3aN+3TkIMV1OtPZXT4OcRb0rFxz/cpQn5nJwwwLW3uiS8Lnv0r/fNEfy5rG0BHkffvorInFq/71EAurm6sYcLOA3BYuWlebIgqsZsLEtMHhts= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720429146; c=relaxed/simple; bh=RenBZxrZQ2uo1BEUtqkw5WbG0pW2r+nrPK0CryNPH8o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gMtHvYGQ86NgdPbsBvYHetdAi289sGWekWsbVVrEZuMzc0GU0OL14U9eJgubu8dz8OzT2yXXAGrgd2Vbm7R50iGd1ZmTRsm78kikbzsKakkt0PWG7AVsSCB9dnrZP7OAjQ2DAMuhB8L/2sfOETVf2nWNDe/IrENBeBF+UPop0A8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mUpoadlI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mUpoadlI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3A4AC116B1; Mon, 8 Jul 2024 08:59:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720429146; bh=RenBZxrZQ2uo1BEUtqkw5WbG0pW2r+nrPK0CryNPH8o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mUpoadlIITe5dJ5HUpP+WWOXnabtiIRVanDlVE+OSEyu6I/ACr+DKp8yGBp75moYq WZWEkqzKC/ijcE4hSbndlwmXZu9Gq8H4qWINe7z0U91MTnfKamQRAF4Ly6St2vKnCR yznMhGZ2AbjtbNc5mFL/DYGAHt5Tpsfrz96Ye6FGDxa1Gx/1rkEgeg6ZjJSTqHx00b pmoegFoMEswOut0YspJ/2xIaVjXZfsfBduocYGCrLCi/wSU/TO9bWHtK3FUZ/BZjg+ a1qSoUmUJZUZmkq7SkMocmYk/UfZqjIdWYlzfH6QSM3UR6KU2ls4yJ8hPHPGqkYeoo vBEhXW80WRMMQ== Date: Mon, 8 Jul 2024 11:59:02 +0300 From: Leon Romanovsky To: Junxian Huang Cc: jgg@ziepe.ca, linux-rdma@vger.kernel.org, linuxarm@huawei.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH for-rc 2/9] RDMA/hns: Fix a long wait for cmdq event during reset Message-ID: <20240708085902.GF6788@unreal> References: <20240705085937.1644229-1-huangjunxian6@hisilicon.com> <20240705085937.1644229-3-huangjunxian6@hisilicon.com> <20240707083007.GE6695@unreal> <42e9f7dd-05bd-176f-c5c0-02e200b3f58c@hisilicon.com> <20240708053850.GA6788@unreal> <7cae577b-e469-9357-8375-d14746a7787b@hisilicon.com> <20240708073315.GC6788@unreal> <0bac285b-c8ae-8c9f-7c42-ee345f8682d1@hisilicon.com> <20240708082755.GD6788@unreal> <26c02b2b-4232-2049-5c9f-f757fef759a0@hisilicon.com> Precedence: bulk X-Mailing-List: linux-rdma@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: <26c02b2b-4232-2049-5c9f-f757fef759a0@hisilicon.com> On Mon, Jul 08, 2024 at 04:45:34PM +0800, Junxian Huang wrote: > > > On 2024/7/8 16:27, Leon Romanovsky wrote: > > On Mon, Jul 08, 2024 at 03:46:26PM +0800, Junxian Huang wrote: > >> > >> > >> On 2024/7/8 15:33, Leon Romanovsky wrote: > >>> On Mon, Jul 08, 2024 at 02:50:50PM +0800, Junxian Huang wrote: > >>>> > >>>> > >>>> On 2024/7/8 13:38, Leon Romanovsky wrote: > >>>>> On Mon, Jul 08, 2024 at 10:29:54AM +0800, Junxian Huang wrote: > >>>>>> > >>>>>> > >>>>>> On 2024/7/7 16:30, Leon Romanovsky wrote: > >>>>>>> On Fri, Jul 05, 2024 at 04:59:30PM +0800, Junxian Huang wrote: > >>>>>>>> From: wenglianfa > >>>>>>>> > >>>>>>>> During reset, cmdq events won't be reported, leading to a long and > >>>>>>>> unnecessary wait. Notify all the cmdqs to stop waiting at the beginning > >>>>>>>> of reset. > >>>>>>>> > >>>>>>>> Fixes: 9a4435375cd1 ("IB/hns: Add driver files for hns RoCE driver") > >>>>>>>> Signed-off-by: wenglianfa > >>>>>>>> Signed-off-by: Junxian Huang > >>>>>>>> --- > >>>>>>>> drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 18 ++++++++++++++++++ > >>>>>>>> 1 file changed, 18 insertions(+) > >>>>>>>> > >>>>>>>> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c > >>>>>>>> index a5d746a5cc68..ff135df1a761 100644 > >>>>>>>> --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c > >>>>>>>> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c > >>>>>>>> @@ -6977,6 +6977,21 @@ static void hns_roce_hw_v2_uninit_instance(struct hnae3_handle *handle, > >>>>>>>> > >>>>>>>> handle->rinfo.instance_state = HNS_ROCE_STATE_NON_INIT; > >>>>>>>> } > >>>>>>>> + > >>>>>>>> +static void hns_roce_v2_reset_notify_cmd(struct hns_roce_dev *hr_dev) > >>>>>>>> +{ > >>>>>>>> + struct hns_roce_cmdq *hr_cmd = &hr_dev->cmd; > >>>>>>>> + int i; > >>>>>>>> + > >>>>>>>> + if (!hr_dev->cmd_mod) > >>>>>>> > >>>>>>> What prevents cmd_mod from being changed? > >>>>>>> > >>>>>> > >>>>>> It's set when the device is being initialized, and won't be changed after that. > >>>>> > >>>>> This is exactly the point, you are assuming that the device is already > >>>>> ininitialized or not initialized at all. What prevents hns_roce_v2_reset_notify_cmd() > >>>>> from being called in the middle of initialization? > >>>>> > >>>>> Thanks > >>>>> > >>>> > >>>> This is ensured by hns3 NIC driver. > >>>> > >>>> Initialization and reset of hns RoCE are both called by hns3. It will check the state > >>>> of RoCE device (see line 3798), and notify RoCE device to reset (hns_roce_v2_reset_notify_cmd() > >>>> is called) only if the RoCE device has been already initialized: > >>> > >>> So why do you have "if (!hr_dev->cmd_mod)" check in the code? > >>> > >>> Thanks > >>> > >> > >> cmd_mod indicates the mode of cmdq (0: poll mode, 1: event mode). > >> This patch only affects event mode because HW won't report events during reset. > > > > You set cmd_mod to 1 in hns_roce_hw_v2_init_instance() without any > > condition, I don't see when hns v2 IB device is created and continue > > to operate in polling mode. > > > > Thanks > > > > Event mode is the default. In hns_roce_cmd_use_events(), if kcalloc() fails > then it'll be set to polling mode instead. 1. Awesome, and we are returning back to the question. What prevents hns_roce_v2_reset_notify_cmd() from being called in the middle of changing cmd_mod from 1 to 0 and from 0 to 1? 2. This cmd_mode swtich from 1 to 0 should be removed. Failure to allocate memory is not a reason to switch to polling mode. The reason can be HW limitation, but not OS limitation. Thanks > > Junxian > > >> > >> Junxian > >> > >>>> > >>>> 3791 static int hclge_notify_roce_client(struct hclge_dev *hdev, > >>>> 3792 enum hnae3_reset_notify_type type) > >>>> 3793 { > >>>> 3794 struct hnae3_handle *handle = &hdev->vport[0].roce; > >>>> 3795 struct hnae3_client *client = hdev->roce_client; > >>>> 3796 int ret; > >>>> 3797 > >>>> 3798 if (!test_bit(HCLGE_STATE_ROCE_REGISTERED, &hdev->state) || !client) > >>>> 3799 return 0; > >>>> 3800 > >>>> 3801 if (!client->ops->reset_notify) > >>>> 3802 return -EOPNOTSUPP; > >>>> 3803 > >>>> 3804 ret = client->ops->reset_notify(handle, type); > >>>> 3805 if (ret) > >>>> 3806 dev_err(&hdev->pdev->dev, "notify roce client failed %d(%d)", > >>>> 3807 type, ret); > >>>> 3808 > >>>> 3809 return ret; > >>>> 3810 } > >>>> > >>>> And the bit is set (see line 11246) after the initialization has been done (line 11242): > >>>> > >>>> 11224 static int hclge_init_roce_client_instance(struct hnae3_ae_dev *ae_dev, > >>>> 11225 struct hclge_vport *vport) > >>>> 11226 { > >>>> 11227 struct hclge_dev *hdev = ae_dev->priv; > >>>> 11228 struct hnae3_client *client; > >>>> 11229 int rst_cnt; > >>>> 11230 int ret; > >>>> 11231 > >>>> 11232 if (!hnae3_dev_roce_supported(hdev) || !hdev->roce_client || > >>>> 11233 !hdev->nic_client) > >>>> 11234 return 0; > >>>> 11235 > >>>> 11236 client = hdev->roce_client; > >>>> 11237 ret = hclge_init_roce_base_info(vport); > >>>> 11238 if (ret) > >>>> 11239 return ret; > >>>> 11240 > >>>> 11241 rst_cnt = hdev->rst_stats.reset_cnt; > >>>> 11242 ret = client->ops->init_instance(&vport->roce); > >>>> 11243 if (ret) > >>>> 11244 return ret; > >>>> 11245 > >>>> 11246 set_bit(HCLGE_STATE_ROCE_REGISTERED, &hdev->state); > >>>> 11247 if (test_bit(HCLGE_STATE_RST_HANDLING, &hdev->state) || > >>>> 11248 rst_cnt != hdev->rst_stats.reset_cnt) { > >>>> 11249 ret = -EBUSY; > >>>> 11250 goto init_roce_err; > >>>> 11251 } > >>>> > >>>> Junxian > >>>> > >>>>>> > >>>>>> Junxian > >>>>>> > >>>>>>>> + return; > >>>>>>>> + > >>>>>>>> + for (i = 0; i < hr_cmd->max_cmds; i++) { > >>>>>>>> + hr_cmd->context[i].result = -EBUSY; > >>>>>>>> + complete(&hr_cmd->context[i].done); > >>>>>>>> + } > >>>>>>>> +} > >>>>>>>> + > >>>>>>>> static int hns_roce_hw_v2_reset_notify_down(struct hnae3_handle *handle) > >>>>>>>> { > >>>>>>>> struct hns_roce_dev *hr_dev; > >>>>>>>> @@ -6997,6 +7012,9 @@ static int hns_roce_hw_v2_reset_notify_down(struct hnae3_handle *handle) > >>>>>>>> hr_dev->dis_db = true; > >>>>>>>> hr_dev->state = HNS_ROCE_DEVICE_STATE_RST_DOWN; > >>>>>>>> > >>>>>>>> + /* Complete the CMDQ event in advance during the reset. */ > >>>>>>>> + hns_roce_v2_reset_notify_cmd(hr_dev); > >>>>>>>> + > >>>>>>>> return 0; > >>>>>>>> } > >>>>>>>> > >>>>>>>> -- > >>>>>>>> 2.33.0 > >>>>>>>> > >>>>>> > >>>> >