[lttng-modules] Fix: bump stable kernel version ranges for clock work-around
Commit Message
Linux commit 27727df240c7 ("Avoid taking lock in NMI path with
CONFIG_DEBUG_TIMEKEEPING"), changed the logic to open-code
the timekeeping_get_ns() function, but forgot to include
the unit conversion from cycles to nanoseconds, breaking the
function's output, which impacts LTTng.
We expected Linux commit 58bfea9532 "timekeeping: Fix
__ktime_get_fast_ns() regression" to make its way into stable
kernels promptly, but it appears new stable kernel releases were
done before the fix was cherry-picked from the master branch.
We therefore need to bump the version ranges for the work-around
in lttng-modules.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
CC: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
CC: John Stultz <john.stultz at linaro.org>
---
wrapper/trace-clock.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
Comments
On Thu, Oct 13, 2016 at 03:56:55PM +0200, Mathieu Desnoyers wrote:
> Linux commit 27727df240c7 ("Avoid taking lock in NMI path with
> CONFIG_DEBUG_TIMEKEEPING"), changed the logic to open-code
> the timekeeping_get_ns() function, but forgot to include
> the unit conversion from cycles to nanoseconds, breaking the
> function's output, which impacts LTTng.
>
> We expected Linux commit 58bfea9532 "timekeeping: Fix
> __ktime_get_fast_ns() regression" to make its way into stable
> kernels promptly, but it appears new stable kernel releases were
> done before the fix was cherry-picked from the master branch.
Sorry, will go queue that up now...
greg k-h
----- On Oct 13, 2016, at 5:00 PM, Greg Kroah-Hartman gregkh at linuxfoundation.org wrote:
> On Thu, Oct 13, 2016 at 03:56:55PM +0200, Mathieu Desnoyers wrote:
>> Linux commit 27727df240c7 ("Avoid taking lock in NMI path with
>> CONFIG_DEBUG_TIMEKEEPING"), changed the logic to open-code
>> the timekeeping_get_ns() function, but forgot to include
>> the unit conversion from cycles to nanoseconds, breaking the
>> function's output, which impacts LTTng.
>>
>> We expected Linux commit 58bfea9532 "timekeeping: Fix
>> __ktime_get_fast_ns() regression" to make its way into stable
>> kernels promptly, but it appears new stable kernel releases were
>> done before the fix was cherry-picked from the master branch.
>
> Sorry, will go queue that up now...
Thanks Greg! :)
Mathieu
@@ -52,10 +52,10 @@ extern struct lttng_trace_clock *lttng_trace_clock;
* CONFIG_DEBUG_TIMEKEEPING") introduces a buggy ktime_get_mono_fast_ns().
* This is fixed by patch "timekeeping: Fix __ktime_get_fast_ns() regression".
*/
-#if (LTTNG_KERNEL_RANGE(4,8,0, 4,8,1) \
- || LTTNG_KERNEL_RANGE(4,7,4, 4,7,7) \
- || LTTNG_KERNEL_RANGE(4,4,20, 4,4,24) \
- || LTTNG_KERNEL_RANGE(4,1,32, 4,1,34))
+#if (LTTNG_KERNEL_RANGE(4,8,0, 4,8,2) \
+ || LTTNG_KERNEL_RANGE(4,7,4, 4,7,8) \
+ || LTTNG_KERNEL_RANGE(4,4,20, 4,4,25) \
+ || LTTNG_KERNEL_RANGE(4,1,32, 4,1,35))
#define LTTNG_CLOCK_NMI_SAFE_BROKEN
#endif