[PATCH v6 tip 7/8] samples: bpf: IO latency analysis (iosnoop/heatmap)

BPF C program attaches to blk_mq_start_request/blk_update_request kprobe events to calculate IO latency. For every completed block IO event it computes the time delta in nsec and records in a histogram map: map[log10(delta)*10]++ User space reads this histogram map every 2 seconds and prints it as

[PATCH v6 tip 7/8] samples: bpf: IO latency analysis (iosnoop/heatmap)

BPF C program attaches to blk_mq_start_request/blk_update_request kprobe events to calculate IO latency. For every completed block IO event it computes the time delta in nsec and records in a histogram map: map[log10(delta)*10]++ User space reads this histogram map every 2 seconds and prints it as