linux_old1/include/trace/events/printk.h

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#undef TRACE_SYSTEM
#define TRACE_SYSTEM printk
#if !defined(_TRACE_PRINTK_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_PRINTK_H
#include <linux/tracepoint.h>
TRACE_EVENT(console,
TP_PROTO(const char *text, size_t len),
TP_ARGS(text, len),
TP_STRUCT__entry(
__dynamic_array(char, msg, len + 1)
),
TP_fast_assign(
printk, tracing: Avoiding unneeded blank lines Printk messages often finish with '\n' to cause a new line. But as each tracepoint is already printed in a new line, printk messages that finish with '\n' ends up adding a blank line to the trace output. For example: kworker/0:1-86 [000] d... 46.006949: console: [ 46.006946] usb 1-3: USB disconnect, device number 3 kworker/2:2-374 [002] d... 48.699342: console: [ 48.699339] usb 1-3: new high-speed USB device number 4 using ehci-pci kworker/2:2-374 [002] d... 49.041450: console: [ 49.041448] usb 1-3: New USB device found, idVendor=5986, idProduct=0 To avoid unneeded blank lines, this patch checks if the printk message finishes with '\n', if so, it cut is off the '\n' to avoid blank lines. In a patched kernel, the same messages are printed without extra blank lines. For example: kworker/0:4-185 [000] d... 23.641738: console: [ 23.641736] usb 1-3: USB disconnect, device number 3 kworker/0:4-185 [000] d... 24.918703: console: [ 24.918700] usb 1-3: new high-speed USB device number 4 using ehci-pci kworker/0:4-185 [000] d... 25.228308: console: [ 25.228306] usb 1-3: New USB device found, idVendor=5986, idProduct=02d5 Link: http://lkml.kernel.org/r/c350fb2521baaf681a1b4d67981ca0e900108e8e.1467407618.git.bristot@redhat.com Cc: Trond Myklebust <trond.myklebust@primarydata.com> Cc: Anna Schumaker <anna.schumaker@netapp.com> Cc: Ingo Molnar <mingo@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-07-02 07:44:37 +08:00
/*
* Each trace entry is printed in a new line.
* If the msg finishes with '\n', cut it off
* to avoid blank lines in the trace.
*/
if ((len > 0) && (text[len-1] == '\n'))
len -= 1;
memcpy(__get_str(msg), text, len);
__get_str(msg)[len] = 0;
),
TP_printk("%s", __get_str(msg))
);
#endif /* _TRACE_PRINTK_H */
/* This part must be outside protection */
#include <trace/define_trace.h>