Here's a patch set that makes /proc/stat report total interrupt counts as monotonically increasing values, just like individual counters for interrupt types and CPUs are. This is as if the sum was a shared counter that all CPUs increment atomically together with their individual counters, with the sum correctly and expectedly wrapping around to zero once it reaches UINT_MAX. I've also added some documentation bits to codify this behavior and make it explicit that wrap-arounds must be expected and handled if userspace wants to maintain accurate total interrupt count for whatever reasons. Alexei Lozovsky (7): genirq: Use unsigned int for irqs_sum powerpc/irq: arch_irq_stat_cpu() returns unsigned int x86/irq: arch_irq_stat_cpu() returns unsigned int x86/irq: arch_irq_stat() returns unsigned int proc/stat: Use unsigned int for "intr" sum proc/stat: Use unsigned int for "softirq" sum docs: proc.rst: stat: Note the interrupt counter wrap-around Documentation/filesystems/proc.rst | 7 +++++++ arch/powerpc/include/asm/hardirq.h | 2 +- arch/powerpc/kernel/irq.c | 4 ++-- arch/x86/include/asm/hardirq.h | 4 ++-- arch/x86/kernel/irq.c | 8 ++++---- fs/proc/stat.c | 8 ++++---- include/linux/kernel_stat.h | 2 +- 7 files changed, 21 insertions(+), 14 deletions(-) -- 2.25.1
