/var/log/messages
Feb  2 11:06:33 web01 kernel: __ratelimit: 6 callbacks suppressed
Feb  2 11:06:38 web01 kernel: __ratelimit: 4 callbacks suppressed
Feb  2 11:06:43 web01 kernel: __ratelimit: 2 callbacks suppressed
Feb  2 11:06:56 web01 kernel: __ratelimit: 14 callbacks suppressed
Feb  2 11:09:18 web01 kernel: __ratelimit: 17 callbacks suppressed
Feb  2 11:09:26 web01 kernel: __ratelimit: 2 callbacks suppressed
Feb  2 11:09:31 web01 kernel: __ratelimit: 15 callbacks suppressed

cat /proc/sys/kernel/printk_ratelimit
5