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rcu/cpu_stall_cputime: fix the hardirq count for x86 architecture

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[ Upstream commit da6b85598af30e9fec34d82882d7e1e39f3da769 ]

When counting the number of hardirqs in the x86 architecture,
it is essential to add arch_irq_stat_cpu to ensure accuracy.

For example, a CPU loop within the rcu_read_lock function.

Before:
[   70.910184] rcu: INFO: rcu_preempt self-detected stall on CPU
[   70.910436] rcu:     3-....: (4999 ticks this GP) idle=***
[   70.910711] rcu:              hardirqs   softirqs   csw/system
[   70.910870] rcu:      number:        0        657            0
[   70.911024] rcu:     cputime:        0          0         2498   ==> 2498(ms)
[   70.911278] rcu:     (t=5001 jiffies g=3677 q=29 ncpus=8)

After:
[   68.046132] rcu: INFO: rcu_preempt self-detected stall on CPU
[   68.046354] rcu:     2-....: (4999 ticks this GP) idle=***
[   68.046628] rcu:              hardirqs   softirqs   csw/system
[   68.046793] rcu:      number:     2498        663            0
[   68.046951] rcu:     cputime:        0          0         2496   ==> 2496(ms)
[   68.047244] rcu:     (t=5000 jiffies g=3825 q=4 ncpus=8)

Fixes: be42f00b73 ("rcu: Add RCU stall diagnosis information")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501090842.SfI6QPGS-lkp@intel.com/
Signed-off-by: Yongliang Gao <leonylgao@tencent.com>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Link: https://lore.kernel.org/r/20250216084109.3109837-1-leonylgao@gmail.com
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yongliang Gao
2025-02-16 16:41:09 +08:00
committed by Greg Kroah-Hartman
parent 402fd6a6fe
commit ec91ab135c
3 changed files with 10 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
kernel/rcu/tree.c
View File

@@ -754,6 +754,10 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp)
return 0; return 0;
} }
#ifndef arch_irq_stat_cpu
#define arch_irq_stat_cpu(cpu) 0
#endif
/* /*
* Returns positive if the specified CPU has passed through a quiescent state * Returns positive if the specified CPU has passed through a quiescent state
* by virtue of being in or having passed through an dynticks idle state since * by virtue of being in or having passed through an dynticks idle state since
@@ -889,9 +893,9 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
rsrp->cputime_irq = kcpustat_field(kcsp, CPUTIME_IRQ, cpu); rsrp->cputime_irq = kcpustat_field(kcsp, CPUTIME_IRQ, cpu);
rsrp->cputime_softirq = kcpustat_field(kcsp, CPUTIME_SOFTIRQ, cpu); rsrp->cputime_softirq = kcpustat_field(kcsp, CPUTIME_SOFTIRQ, cpu);
rsrp->cputime_system = kcpustat_field(kcsp, CPUTIME_SYSTEM, cpu); rsrp->cputime_system = kcpustat_field(kcsp, CPUTIME_SYSTEM, cpu);
rsrp->nr_hardirqs = kstat_cpu_irqs_sum(rdp->cpu); rsrp->nr_hardirqs = kstat_cpu_irqs_sum(cpu) + arch_irq_stat_cpu(cpu);
rsrp->nr_softirqs = kstat_cpu_softirqs_sum(rdp->cpu); rsrp->nr_softirqs = kstat_cpu_softirqs_sum(cpu);
rsrp->nr_csw = nr_context_switches_cpu(rdp->cpu); rsrp->nr_csw = nr_context_switches_cpu(cpu);
rsrp->jiffies = jiffies; rsrp->jiffies = jiffies;
rsrp->gp_seq = rdp->gp_seq; rsrp->gp_seq = rdp->gp_seq;
} }

2
kernel/rcu/tree.h
View File

@@ -169,7 +169,7 @@ struct rcu_snap_record {
u64 cputime_irq; /* Accumulated cputime of hard irqs */ u64 cputime_irq; /* Accumulated cputime of hard irqs */
u64 cputime_softirq;/* Accumulated cputime of soft irqs */ u64 cputime_softirq;/* Accumulated cputime of soft irqs */
u64 cputime_system; /* Accumulated cputime of kernel tasks */ u64 cputime_system; /* Accumulated cputime of kernel tasks */
unsigned long nr_hardirqs; /* Accumulated number of hard irqs */ u64 nr_hardirqs; /* Accumulated number of hard irqs */
unsigned int nr_softirqs; /* Accumulated number of soft irqs */ unsigned int nr_softirqs; /* Accumulated number of soft irqs */
unsigned long long nr_csw; /* Accumulated number of task switches */ unsigned long long nr_csw; /* Accumulated number of task switches */
unsigned long jiffies; /* Track jiffies value */ unsigned long jiffies; /* Track jiffies value */

4
kernel/rcu/tree_stall.h
View File

@@ -452,8 +452,8 @@ static void print_cpu_stat_info(int cpu)
rsr.cputime_system = kcpustat_field(kcsp, CPUTIME_SYSTEM, cpu); rsr.cputime_system = kcpustat_field(kcsp, CPUTIME_SYSTEM, cpu);
pr_err("\t hardirqs softirqs csw/system\n"); pr_err("\t hardirqs softirqs csw/system\n");
pr_err("\t number: %8ld %10d %12lld\n", pr_err("\t number: %8lld %10d %12lld\n",
kstat_cpu_irqs_sum(cpu) - rsrp->nr_hardirqs, kstat_cpu_irqs_sum(cpu) + arch_irq_stat_cpu(cpu) - rsrp->nr_hardirqs,
kstat_cpu_softirqs_sum(cpu) - rsrp->nr_softirqs, kstat_cpu_softirqs_sum(cpu) - rsrp->nr_softirqs,
nr_context_switches_cpu(cpu) - rsrp->nr_csw); nr_context_switches_cpu(cpu) - rsrp->nr_csw);
pr_err("\tcputime: %8lld %10lld %12lld ==> %d(ms)\n", pr_err("\tcputime: %8lld %10lld %12lld ==> %d(ms)\n",