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Tue, 9 Sep 2025 12:21:53 +0000 (GMT) Message-ID: Date: Tue, 9 Sep 2025 17:51:51 +0530 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH for-6.18/block 08/10] blk-mq: fix potential deadlock while nr_requests grown To: Yu Kuai , ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com References: <20250908061533.3062917-1-yukuai1@huaweicloud.com> <20250908061533.3062917-9-yukuai1@huaweicloud.com> Content-Language: en-US From: Nilay Shroff In-Reply-To: <20250908061533.3062917-9-yukuai1@huaweicloud.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: sLLKeMBLjgSL_T0Rfdt3xaNP907hJex5 X-Proofpoint-ORIG-GUID: sLLKeMBLjgSL_T0Rfdt3xaNP907hJex5 X-Authority-Analysis: v=2.4 cv=J52q7BnS c=1 sm=1 tr=0 ts=68c01be6 cx=c_pps a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17 a=IkcTkHD0fZMA:10 a=yJojWOMRYYMA:10 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=i0EeH86SAAAA:8 a=5m0jnhctum0_gvrSJaQA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwOTA2MDAyNSBTYWx0ZWRfX/swE9qgZ1A1u a/5X7jLp40465RnH3HV2yXx7ajiCRFN8MIjIClXY1XOjacW08Tvl9Kva6t+jB2SpO2e9XaXSYB0 UNZr8mTN6otBWsp15dCbzkAPX0NAc28WVB97bm2KGjXCE4mCaR8K5V1csHmC1BovAQZbbtn0Qwo vM6wm2M039RKJ0XJ/svXD04CDyma4t6Tsx4/w64pUlScmSqHtClo+Yd50ZhP22llxUkUh7lVxxV 9uSkVx72h6wQE+MzzMI+UajDrfA7ns1xwnjpS2iyEcSTeudVSxcSMQLhOHZ7LrCnrbgvNYxxblP R7tv3BqPZIqGAbN6oUTr0sBWGkkURU4Tn5pVnqCFSis3j8w4ccrMSQ+Fz0P1e/FwL+0lFvJvwHT OzWu3KdN X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1117,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-09-09_01,2025-09-08_02,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 clxscore=1015 suspectscore=0 spamscore=0 phishscore=0 bulkscore=0 adultscore=0 malwarescore=0 priorityscore=1501 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2507300000 definitions=main-2509060025 On 9/8/25 11:45 AM, Yu Kuai wrote: > From: Yu Kuai > > Allocate and free sched_tags while queue is freezed can deadlock[1], > this is a long term problem, hence allocate memory before freezing > queue and free memory after queue is unfreezed. > > [1] https://lore.kernel.org/all/0659ea8d-a463-47c8-9180-43c719e106eb@linux.ibm.com/ > Fixes: e3a2b3f931f5 ("blk-mq: allow changing of queue depth through sysfs") > > Signed-off-by: Yu Kuai Looks good to me: Reviewed-by: Nilay Shroff