Fix: work-around upstream Linux timekeeping bug

[lttng-modules.git] / wrapper / trace-clock.h

diff --git a/wrapper/trace-clock.h b/wrapper/trace-clock.h
index ad600ddce31fc8c1a1823d5a21a9c5d3bf029c61..001b4f404298f55c77784c8f256905192dbbd2d0 100644 (file)
--- a/wrapper/trace-clock.h
+++ b/wrapper/trace-clock.h
@@ -44,7 +44,16 @@
 #error "Linux kernels 3.10 and 3.11 introduce a deadlock in the timekeeping subsystem. Fixed by commit 7bd36014460f793c19e7d6c94dab67b0afcfcb7f \"timekeeping: Fix HRTICK related deadlock from ntp lock changes\" in Linux."
 #endif
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0))
+/*
+ * Upstream Linux commit 27727df240c7 ("Avoid taking lock in NMI path with
+ * CONFIG_DEBUG_TIMEKEEPING") introduces a buggy ktime_get_mono_fast_ns().
+ * This is fixed by patch "timekeeping: Fix __ktime_get_fast_ns() regression".
+ */
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) \
+       && !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))
 
 DECLARE_PER_CPU(local_t, lttng_last_tsc);