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78aebca2c9
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>
36 lines
747 B
C
36 lines
747 B
C
#undef TRACE_SYSTEM
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#define TRACE_SYSTEM printk
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#if !defined(_TRACE_PRINTK_H) || defined(TRACE_HEADER_MULTI_READ)
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#define _TRACE_PRINTK_H
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#include <linux/tracepoint.h>
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TRACE_EVENT(console,
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TP_PROTO(const char *text, size_t len),
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TP_ARGS(text, len),
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TP_STRUCT__entry(
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__dynamic_array(char, msg, len + 1)
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),
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TP_fast_assign(
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/*
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* Each trace entry is printed in a new line.
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* If the msg finishes with '\n', cut it off
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* to avoid blank lines in the trace.
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*/
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if ((len > 0) && (text[len-1] == '\n'))
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len -= 1;
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memcpy(__get_str(msg), text, len);
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__get_str(msg)[len] = 0;
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),
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TP_printk("%s", __get_str(msg))
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);
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#endif /* _TRACE_PRINTK_H */
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/* This part must be outside protection */
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#include <trace/define_trace.h>
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