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| author | Zhen Lei <thunder.leizhen@huawei.com> | 2023-07-24 10:26:51 +0800 |
|---|---|---|
| committer | Frederic Weisbecker <frederic@kernel.org> | 2023-09-11 21:48:36 +0200 |
| commit | 243d5ab34446854ceca55146fc0d837655657f8e (patch) | |
| tree | d0e0aec86e136d14b12247efbaab3775b85b9e50 /kernel/rcu | |
| parent | f3efe02fd56e2498ad8da4c4f444a34aa1456a46 (diff) | |
| download | linux-243d5ab34446854ceca55146fc0d837655657f8e.tar.gz linux-243d5ab34446854ceca55146fc0d837655657f8e.tar.bz2 linux-243d5ab34446854ceca55146fc0d837655657f8e.zip | |
rcu: Eliminate check_cpu_stall() duplicate code
The code and comments of self-detected and other-detected RCU CPU stall
warnings are identical except the output function. This commit therefore
refactors so as to consolidate the duplicate code.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree_stall.h | 42 |
1 files changed, 15 insertions, 27 deletions
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index fc04a8d7ce96..2443d1d4a6dc 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); + } } } |