On Fri, 2019-05-31 at 14:40 +0800, Wanpeng Li wrote: > The trailing newlines will lead to extra newlines in the trace file [] > diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h [] > @@ -1365,7 +1365,7 @@ TRACE_EVENT(kvm_hv_timer_state, > __entry->vcpu_id = vcpu_id; > __entry->hv_timer_in_use = hv_timer_in_use; > ), > - TP_printk("vcpu_id %x hv_timer %x\n", > + TP_printk("vcpu_id %x hv_timer %x", > __entry->vcpu_id, > __entry->hv_timer_in_use) > ); Not about the kvm subsystem, but generically there are many of these that could be removed. $ git grep -w TP_printk | grep '\\n' | wc -l 45 Also, aren't all TP_printk formats supposed to be single line? If not, these are odd as well. $ git grep -w TP_printk | grep '\\n[^"]' include/trace/events/9p.h: TP_printk("clnt %lu %s(tag = %d)\n%.3x: %16ph\n%.3x: %16ph\n", net/tipc/trace.h: TP_printk("%s\n%s", __get_str(header), __get_str(buf)) net/tipc/trace.h: TP_printk("%s\n%s", __get_str(header), __get_str(buf)) net/tipc/trace.h: TP_printk("<%u> %s\n%s%s", __entry->portid, __get_str(header), net/tipc/trace.h: TP_printk("<%s> %s\n%s", __entry->name, __get_str(header), net/tipc/trace.h: TP_printk("<%x> %s\n%s", __entry->addr, __get_str(header), Perhaps the documentation files around these formats Documentation/trace/events.rst Documentation/trace/tracepoints.rst could be improved as well.