| Message ID | 20230724022651.899-2-thunder.leizhen@huaweicloud.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | dd111328533f67165a8713b6cd83799a0a74ca5c |
| Headers | show |
| Series | rcu: Simplify check_cpu_stall() | expand |
On Mon, Jul 24, 2023 at 10:26:51AM +0800, thunder.leizhen@huaweicloud.com wrote: > From: Zhen Lei <thunder.leizhen@huawei.com> > > The code and comments of self detected and other detected are the same > except the output function. Combine the same parts to avoid duplication. > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Queued and pushed, thank you!!! Thanx, Paul > --- > kernel/rcu/tree_stall.h | 42 +++++++++++++++-------------------------- > 1 file changed, 15 insertions(+), 27 deletions(-) > > diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h > index cc884cd49e026a3..b45d7e49944cdd7 100644 > --- a/kernel/rcu/tree_stall.h > +++ b/kernel/rcu/tree_stall.h > @@ -711,7 +711,7 @@ static void print_cpu_stall(unsigned long gps) > > static void check_cpu_stall(struct rcu_data *rdp) > { > - bool didstall = false; > + bool self_detected; > unsigned long gs1; > unsigned long gs2; > unsigned long gps; > @@ -758,10 +758,10 @@ static void check_cpu_stall(struct rcu_data *rdp) > return; /* No stall or GP completed since entering function. */ > rnp = rdp->mynode; > jn = jiffies + ULONG_MAX / 2; > + self_detected = READ_ONCE(rnp->qsmask) & rdp->grpmask; > if (rcu_gp_in_progress() && > - (READ_ONCE(rnp->qsmask) & rdp->grpmask) && > + (self_detected || ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY)) && > cmpxchg(&rcu_state.jiffies_stall, js, jn) == js) { > - > /* > * If a virtual machine is stopped by the host it can look to > * the watchdog like an RCU stall. Check to see if the host > @@ -770,33 +770,21 @@ static void check_cpu_stall(struct rcu_data *rdp) > if (kvm_check_and_clear_guest_paused()) > return; > > - /* We haven't checked in, so go dump stack. */ > - print_cpu_stall(gps); > - if (READ_ONCE(rcu_cpu_stall_ftrace_dump)) > - rcu_ftrace_dump(DUMP_ALL); > - didstall = true; > - > - } else if (rcu_gp_in_progress() && > - ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY) && > - cmpxchg(&rcu_state.jiffies_stall, js, jn) == js) { > - > - /* > - * If a virtual machine is stopped by the host it can look to > - * the watchdog like an RCU stall. Check to see if the host > - * stopped the vm. > - */ > - if (kvm_check_and_clear_guest_paused()) > - return; > + if (self_detected) { > + /* We haven't checked in, so go dump stack. */ > + print_cpu_stall(gps); > + } else { > + /* They had a few time units to dump stack, so complain. */ > + print_other_cpu_stall(gs2, gps); > + } > > - /* They had a few time units to dump stack, so complain. */ > - print_other_cpu_stall(gs2, gps); > if (READ_ONCE(rcu_cpu_stall_ftrace_dump)) > rcu_ftrace_dump(DUMP_ALL); > - didstall = true; > - } > - if (didstall && READ_ONCE(rcu_state.jiffies_stall) == jn) { > - jn = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; > - WRITE_ONCE(rcu_state.jiffies_stall, jn); > + > + if (READ_ONCE(rcu_state.jiffies_stall) == jn) { > + jn = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; > + WRITE_ONCE(rcu_state.jiffies_stall, jn); > + } > } > } > > -- > 2.25.1 >
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index cc884cd49e026a3..b45d7e49944cdd7 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -711,7 +711,7 @@ static void print_cpu_stall(unsigned long gps) static void check_cpu_stall(struct rcu_data *rdp) { - bool didstall = false; + bool self_detected; unsigned long gs1; unsigned long gs2; unsigned long gps; @@ -758,10 +758,10 @@ static void check_cpu_stall(struct rcu_data *rdp) return; /* No stall or GP completed since entering function. */ rnp = rdp->mynode; jn = jiffies + ULONG_MAX / 2; + self_detected = READ_ONCE(rnp->qsmask) & rdp->grpmask; if (rcu_gp_in_progress() && - (READ_ONCE(rnp->qsmask) & rdp->grpmask) && + (self_detected || ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY)) && cmpxchg(&rcu_state.jiffies_stall, js, jn) == js) { - /* * If a virtual machine is stopped by the host it can look to * the watchdog like an RCU stall. Check to see if the host @@ -770,33 +770,21 @@ static void check_cpu_stall(struct rcu_data *rdp) if (kvm_check_and_clear_guest_paused()) return; - /* We haven't checked in, so go dump stack. */ - print_cpu_stall(gps); - if (READ_ONCE(rcu_cpu_stall_ftrace_dump)) - rcu_ftrace_dump(DUMP_ALL); - didstall = true; - - } else if (rcu_gp_in_progress() && - ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY) && - cmpxchg(&rcu_state.jiffies_stall, js, jn) == js) { - - /* - * If a virtual machine is stopped by the host it can look to - * the watchdog like an RCU stall. Check to see if the host - * stopped the vm. - */ - if (kvm_check_and_clear_guest_paused()) - return; + if (self_detected) { + /* We haven't checked in, so go dump stack. */ + print_cpu_stall(gps); + } else { + /* They had a few time units to dump stack, so complain. */ + print_other_cpu_stall(gs2, gps); + } - /* They had a few time units to dump stack, so complain. */ - print_other_cpu_stall(gs2, gps); if (READ_ONCE(rcu_cpu_stall_ftrace_dump)) rcu_ftrace_dump(DUMP_ALL); - didstall = true; - } - if (didstall && READ_ONCE(rcu_state.jiffies_stall) == jn) { - jn = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; - WRITE_ONCE(rcu_state.jiffies_stall, jn); + + if (READ_ONCE(rcu_state.jiffies_stall) == jn) { + jn = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; + WRITE_ONCE(rcu_state.jiffies_stall, jn); + } } }