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authorBitao Hu <yaoma@linux.alibaba.com>2024-04-11 10:41:31 +0300
committerThomas Gleixner <tglx@linutronix.de>2024-04-12 18:08:05 +0300
commit99cf63c56661be0a0c42f79b56f37a4aa34b4779 (patch)
tree10cdfb0ae0ed029482ac5f33efcaad5092fc7ffb /include/linux/irqdesc.h
parent86d2a2f51fbada84e377665df06b5a479a1edc99 (diff)
downloadlinux-99cf63c56661be0a0c42f79b56f37a4aa34b4779.tar.xz
genirq: Provide a snapshot mechanism for interrupt statistics
The soft lockup detector lacks a mechanism to identify interrupt storms as root cause of a lockup. To enable this the detector needs a mechanism to snapshot the interrupt count statistics on a CPU when the detector observes a potential lockup scenario and compare that against the interrupt count when it warns about the lockup later on. The number of interrupts in that period give a hint whether the lockup might have been caused by an interrupt storm. Instead of having extra storage in the lockup detector and accessing the internals of the interrupt descriptor directly, add a snapshot member to the per CPU irq_desc::kstat_irq structure and provide interfaces to take a snapshot of all interrupts on the current CPU and to retrieve the delta of a specific interrupt later on. Originally-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240411074134.30922-3-yaoma@linux.alibaba.com
Diffstat (limited to 'include/linux/irqdesc.h')
-rw-r--r--include/linux/irqdesc.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index c28612674acb..fd091c35d572 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -20,9 +20,13 @@ struct pt_regs;
/**
* struct irqstat - interrupt statistics
* @cnt: real-time interrupt count
+ * @ref: snapshot of interrupt count
*/
struct irqstat {
unsigned int cnt;
+#ifdef CONFIG_GENERIC_IRQ_STAT_SNAPSHOT
+ unsigned int ref;
+#endif
};
/**