wrapper/trace-clock.c

   1 /*
   2  * wrapper/trace-clock.c
   3  *
   4  * Contains LTTng trace clock mapping to LTTng trace clock or mainline monotonic
   5  * clock. This wrapper depends on CONFIG_HIGH_RES_TIMERS=y.
   6  *
   7  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; only
  12  * version 2.1 of the License.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #include <wrapper/trace-clock.h>
  25
  26 #ifdef LTTNG_USE_NMI_SAFE_CLOCK
  27 DEFINE_PER_CPU(u64, lttng_last_tsc);
  28 EXPORT_PER_CPU_SYMBOL(lttng_last_tsc);
  29 #endif /* #ifdef LTTNG_USE_NMI_SAFE_CLOCK */
  30
  31 #ifdef LTTNG_CLOCK_NMI_SAFE_BROKEN
  32 #warning "Your kernel implements a bogus nmi-safe clock source. Falling back to the non-nmi-safe clock source, which discards events traced from NMI context. Upgrade your kernel to resolve this situation."
  33 #endif