解释RCU的CPU停顿检测器 "Splats" 对于RCU的非RCU-tasks类型,当CPU检测到它正在停止时,它将打印类似于以下内容的消息: INFO: rcu_sched detected stalls on CPUs/tasks: 2-...: (3 GPs behind) idle=06c/0/0 softirq=1453/1455 fqs=0 16-...: (0 ticks this GP) idle=81c/0/0 softirq=764/764...
294 If an expedited grace period detects a stall, it will place a message 295 like the following in dmesg: 296 297 INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 7-... } 21119 jiffies s: 73 root:0x2/. 298 299 This indicates that CPU 7 has failed to respond to a res...
[ 607.238125] rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 1-... } 6001 jiffies s: 141 root: 0x2/. [ 607.249073] rcu: blocking rcu_node structures (internal RCU debug): [ 607.255417] Task dump for CPU 1: [ 607.258823] task:napi/phy0-9 state:R running task st...
INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 7-... } 21119 jiffies s: 73 root: 0x2/. 这表明 CPU 7 未能响应重新调度 IPI。 CPU 编号后面的三个句点 (“.”) 表示 CPU 处于联机状态(否则第一个周期将改为“O”),CPU 在加速宽限期开始时处于联机状态(否则第二个周期将改为“o...
[RCUstall]RCUstall分析,RCUstall内核文档翻译 [RCUstall]RCUstall分析,RCUstall内核⽂档翻译 使⽤RCU的CPU失速检测器 本⽂档⾸先讨论RCU的CPU停顿检测器可以定位哪些问题,然后讨论可⽤于微调检测器操作的内核参数和Kconfig选项。最后,本⽂解释了失速检测器的“splat”格式。是什么导致RCU CPU停顿警告?是...
[ 259.077037][ T141] rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 0-... } 15632 jiffies s: 2777 root: 0x1/. [ 259.078906][ T141] rcu: blocking rcu_node structures: [ 259.079761][ T141] Task dump for CPU 0: [ 259.080460][ T141] task:syz-executor.3 state:...
与RCU-preempt一样,RCU-sched的synchronize_rcu_expedited()忽略离线和空闲的CPU,因为它们处于远程可检测的静止状态。然而,由于rcu_read_lock_sched()和rcu_read_unlock_sched()没有留下它们调用的痕迹,通常无法确定当前CPU是否处于RCU读取侧临界区。RCU-sched的rcu_exp_handler()能做的最好的事情就是检查空闲状态...
rcu_seq_start(&rcu_state.expedited_sequence); } /* * Return the value that the expedited-grace-period counter will have * at the end of the current grace period.*/ static __maybe_unused unsigned long rcu_exp_gp_seq_endval(void) ...
INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { P0 } 67953 jiffies s: 1039 root: 0x0/T blocking rcu_node structures: systemd-hostnamed.service: Processes still around after final SIGKILL. Entering failed mode. systemd-hostnamed.service: Unit entered failed state. ...
No RCU stalls, copy_to_user actions fault correctly in the kernel and free up the CPU again Actual Behavior System locks up. Diagnostic Logs When the kernel is built withCONFIG_RSEQ: [ 1301.906019] rcu: INFO: rcu_sched self-detected stall on CPU [ 1301.907897] rcu: 1-...: (104816 ti...