All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH lttng-modules] Fix: bump stable kernel version ranges for clock work-around
@ 2016-10-13 13:56 Mathieu Desnoyers
  2016-10-13 15:00 ` Greg Kroah-Hartman
  0 siblings, 1 reply; 5+ messages in thread
From: Mathieu Desnoyers @ 2016-10-13 13:56 UTC (permalink / raw)
  To: Greg Kroah-Hartman, linux-kernel
  Cc: lttng-dev, Mathieu Desnoyers, John Stultz

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@efficios.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: John Stultz <john.stultz@linaro.org>
---
 wrapper/trace-clock.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/wrapper/trace-clock.h b/wrapper/trace-clock.h
index 14d41af..496fec4 100644
--- a/wrapper/trace-clock.h
+++ b/wrapper/trace-clock.h
@@ -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
 
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 5+ messages in thread
* [PATCH lttng-modules] Fix: bump stable kernel version ranges for clock work-around
@ 2016-10-13 13:56 Mathieu Desnoyers
  0 siblings, 0 replies; 5+ messages in thread
From: Mathieu Desnoyers @ 2016-10-13 13:56 UTC (permalink / raw)
  To: Greg Kroah-Hartman, linux-kernel; +Cc: John Stultz, lttng-dev

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@efficios.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: John Stultz <john.stultz@linaro.org>
---
 wrapper/trace-clock.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/wrapper/trace-clock.h b/wrapper/trace-clock.h
index 14d41af..496fec4 100644
--- a/wrapper/trace-clock.h
+++ b/wrapper/trace-clock.h
@@ -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
 
-- 
2.1.4

_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

^ permalink raw reply related	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-10-13 15:10 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-10-13 13:56 [PATCH lttng-modules] Fix: bump stable kernel version ranges for clock work-around Mathieu Desnoyers
2016-10-13 15:00 ` Greg Kroah-Hartman
2016-10-13 15:09   ` Mathieu Desnoyers
2016-10-13 15:09   ` Mathieu Desnoyers
  -- strict thread matches above, loose matches on Subject: below --
2016-10-13 13:56 Mathieu Desnoyers

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.