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Wed, 10 Sep 2025 10:11:13 +0000 (GMT) Message-ID: <8abbf00d-b1de-48cb-8310-3c8d0a3018cf@linux.ibm.com> Date: Wed, 10 Sep 2025 15:41:12 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 for-6.18/block 08/10] blk-mq: fix potential deadlock while nr_requests grown To: Yu Kuai , axboe@kernel.dk, ming.lei@redhat.com 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: <20250910080445.239096-1-yukuai1@huaweicloud.com> <20250910080445.239096-9-yukuai1@huaweicloud.com> Content-Language: en-US From: Nilay Shroff In-Reply-To: <20250910080445.239096-9-yukuai1@huaweicloud.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: tsDC_Qbkt1Be8o4DT8mRM1wPuVwUYkAA X-Proofpoint-ORIG-GUID: tsDC_Qbkt1Be8o4DT8mRM1wPuVwUYkAA X-Authority-Analysis: v=2.4 cv=J52q7BnS c=1 sm=1 tr=0 ts=68c14ec7 cx=c_pps a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17 a=IkcTkHD0fZMA:10 a=yJojWOMRYYMA:10 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=i0EeH86SAAAA:8 a=ULAgg6nowICSNR1rqZIA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwOTA2MDAyNSBTYWx0ZWRfX1ovhveqwWsyW vS+U8dS4aVn592yt+XnOV1JQzRv3w6tf1Tj2DvqcjgvEpwfRcwg7fJN912xFO3ygdQJO7WewMxv fWI4SxR+EgTORxdk1dw2wmNd5sFoFKOQDWGjNsd3bQny75nxlVyC5ZakhwEoeoOgNrBkKcVST6N ZhhgYnw+WWv1ois+S7InJ2wVNHd7wka/qI80+QL1Y8lmj4a4a/J/VGbLxMn0OnSQ35yiGUzXbjQ 9I8Qk8sztbheB6Fl53c0RdsIvB1OaK4UECpz1G0AA6CT0vJnVZBwi/Ar1qM1832NM0qhbHslbJu 9OF4lKKWM6o7l/CeFoN3vMdvjjeXKfHkulMXwGbSya5m4KZl6Li1vI/yMVTSoZbl0gTtuG+8mUV ZRLqGIgX 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_03,2025-09-10_01,2025-03-28_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 9/10/25 1:34 PM, 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