103 2021-12-16 14:51:44 +0000 [ANCK 4.19] io_uring async buffered reads 特性在 epoll 等场景下存在hang的可能 2022-08-16 11:53:07 +0000 1 1 5 ANCK ANCK 4.19 Dev fs 4.19-025.x All Linux RESOLVED FIXED P1-Urgent S2-major --- 1 joseph.qi xiaoguang.wang haoxu quentin.sqm xiaoguang.wang oldest_to_newest 166 0 joseph.qi 2021-12-16 14:51:44 +0000 我们在backport async buffered reads特性时，并没有将task_work_add的调用全部转为io_req_task_work_add, 导致async buffered reads唤醒时仍然使用的是TWA_RESUME，导致处于 interruptible 状态的等待者不能及时被唤醒，从而导致应用hang。 170 1 joseph.qi 2021-12-16 14:59:47 +0000 *** Bug 98 has been marked as a duplicate of this bug. *** 173 2 joseph.qi 2021-12-16 15:00:23 +0000 *** Bug 99 has been marked as a duplicate of this bug. *** 177 3 joseph.qi 2021-12-16 15:01:11 +0000 *** Bug 100 has been marked as a duplicate of this bug. *** 179 4 joseph.qi 2021-12-16 15:01:35 +0000 *** Bug 101 has been marked as a duplicate of this bug. *** 186 5 haoxu 2021-12-16 15:55:03 +0000 (In reply to josephqi from comment #0) > 我们在backport async buffered > reads特性时，并没有将task_work_add的调用全部转为io_req_task_work_add, 导致async buffered > reads唤醒时仍然使用的是TWA_RESUME，导致处于 interruptible 状态的等待者不能及时被唤醒，从而导致应用hang。 准确来说应该是RESUME会唤醒 interruptible的线程，但是对于正运行在用户态的线程没有效果。因而可能出现后者如果不再次进入内核态，task work就不会被处理的情况。 302 6 joseph.qi 2021-12-22 10:31:12 +0000 https://gitee.com/anolis/cloud-kernel/pulls/51