阶段2 处理强制静止态: //通过下文我们可以看到真正的qsmask=0且无blocked进程的情况直接return,当过载被设置FQS事件或gp超时都会进行一次fqs任务。 ->rcu_gp_fqs_loop ->swait_event_idle_timeout_exclusive //睡眠。唤醒情况:1.callback过载 2.FQS flag被设置 3.root rcu node的qsmask为0且无block进程 ...
> to acquire the ->lock nor does it need the loop overhead. >2. There are multiple levels. In this case, as you say, the root > rcu_node structure's ->blkd_tasks list will always be empty. > But also in this case, the root rcu_node structure's ->qsmask > cannot be zero u...
这种情况发生在cpu关了中断后一直loop,或者在打了rt patch的内核中,一个高优先级的任务饿死了rcu 软中断处理函数。 214 The "fqs=" shows the number of force-quiescent-state idle/offline 215 detection passes that the grace-period kthread has made across this 216 CPU since the last time that this...
struct task_struct *gpk = rcu_state.gp_kthread; short gp_state; unsigned long jiffies_fqs; int cpu; /* * Order reads of .gp_state and .jiffies_force_qs.* Matching smp_wmb() is present in rcu_gp_fqs_loop().*/
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[ 1739.451891] rcu: INFO: rcu_sched self-detected stall on CPU [ 1739.452511] rcu: 7-...: (59616 ticks this GP) idle=d4ec/1/0x4000000000000000 softirq=18636/18636 fqs=5263 [ 1739.453498] rcu: (t=60008 jiffies g=67965 q=36939 ncpus=8) [ 1739.454053] rcu: rcu_sched kthread starved...
Part Number: TMDS64EVM Other Parts Discussed in Thread: SYSCONFIG , We are using the non-standard booting flow, where R5 core is booted first, and then it boots
The backtraces suggest that none of the active tasks is holding the spinlock. Check the detail of an out-of-tree (O) kernel module:[oracleoks] Raw crash> mod -t | grep -e NAME -e oracleoks NAME TAINTS oracleoks POE crash> mod | grep -e NAME -e oracleoks MODULE NAME BASE SIZE ...
static unsigned long rcu_exp_gp_seq_snap(void) { unsigned long s; smp_mb(); /* Caller's modifications seen first by other CPUs. */ s = rcu_seq_snap(&rcu_state.expedited_sequence); trace_rcu_exp_grace_period(rcu_state.name, s, TPS("snap")); ...
(rsp); 如果不需要开启一个新的gp: if (!cpu_needs_another_gp(rsp, rdp) || rsp-fqs_active) { if (cpu_needs_another_gp(rsp, rdp)) rsp-fqs_need_gp = 1; if (rnp-completed == rsp-completed) { raw_spin_unlock_irqrestore(rnp-lock, flags); return; } raw_spin_unlock(rnp-lock);...