kernel.git/include/trace/events/printk.h, branch linux-4.13.y

printk, tracing: Avoiding unneeded blank lines

2016-07-15T19:52:41Z

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 Cc: Anna Schumaker Cc: Ingo Molnar Reviewed-by: Steven Rostedt Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt

tracing: Use __get_str() when manipulating strings

2016-07-15T19:52:20Z

Use __get_str(str) rather than __get_dynamic_array(str) when deadling with strings. It is just a code cleanup, no changes on tracepoint ABI. Link: http://lkml.kernel.org/r/ea260df91817411cca2a1f3db2abd88860094788.1467407618.git.bristot@redhat.com Cc: Trond Myklebust Cc: Anna Schumaker Cc: Ingo Molnar Cc: linux-nfs@vger.kernel.org Suggested-by: Steven Rostedt Reviewed-by: Steven Rostedt Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt

printk/tracing: rework console tracing

2013-04-30T01:28:13Z

Commit 7ff9554bb578 ("printk: convert byte-buffer to variable-length record buffer") removed start and end parameters from call_console_drivers, but those parameters still exist in include/trace/events/printk.h. Without start and end parameters handling, printk tracing became more simple as: trace_console(text, len); Signed-off-by: zhangwei(Jovi) Acked-by: Steven Rostedt Acked-by: Frederic Weisbecker Cc: Kay Sievers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

printk/tracing: Add console output tracing

2012-02-13T18:46:05Z

Add a printk.console trace point to record any printk messages into the trace, regardless of the current console loglevel. This can help correlate (existing) printk debugging with other tracing. Link: http://lkml.kernel.org/r/1322161388.5366.54.camel@jlt3.sipsolutions.net Acked-by: Frederic Weisbecker Cc: Christoph Hellwig Cc: Ingo Molnar Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Signed-off-by: Johannes Berg Signed-off-by: Steven Rostedt