Tony Luck found that using the "uptime" trace clock that uses jiffies

Browse source

as a counter was converted to nanoseconds (silly), and after 1 hour
 11 minutes and 34 seconds, this monotonic clock would wrap, causing
 havoc with the tracing system and making the clock useless.
 
 He converted that clock to use jiffies_64 and made it into a counter
 instead of nanosecond conversions, and displayed the clock with the
 straight jiffy count, which works much better than it did in the past.
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Merge tag 'trace-fixes-v3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull trace fix from Steven Rostedt:
 "Tony Luck found that using the "uptime" trace clock that uses jiffies
  as a counter was converted to nanoseconds (silly), and after 1 hour 11
  minutes and 34 seconds, this monotonic clock would wrap, causing havoc
  with the tracing system and making the clock useless.

  He converted that clock to use jiffies_64 and made it into a counter
  instead of nanosecond conversions, and displayed the clock with the
  straight jiffy count, which works much better than it did in the past"

* tag 'trace-fixes-v3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix wraparound problems in "uptime" trace clock

...

This commit is contained in:

Linus Torvalds 2014-07-21 22:43:15 -07:00

parent 67dd8f35c2 58d4e21e50

commit 8dcc3be2a4

2 changed files with 6 additions and 5 deletions

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2

kernel/trace/trace.c

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9

kernel/trace/trace_clock.c

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