diff options
Diffstat (limited to 'lib/timeval.h')
| -rw-r--r-- | lib/timeval.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/lib/timeval.h b/lib/timeval.h index d9eb3c7a6..cb5191c5e 100644 --- a/lib/timeval.h +++ b/lib/timeval.h @@ -44,6 +44,22 @@ BUILD_ASSERT_DECL(TYPE_IS_SIGNED(time_t)); * much time will be wasted in signal handlers and calls to clock_gettime(). */ #define TIME_UPDATE_INTERVAL 100 +/* True on systems (particularly x86-64 Linux) where clock_gettime() is + * inexpensive. On these systems, we don't bother caching the current time. + * Instead, we consult clock_gettime() directly when needed. + * + * False on systems where clock_gettime() is relatively expensive. On these + * systems, we cache the current time and set up a periodic SIGALRM to remind + * us to update it. + * + * Also false on systems (e.g. ESX) that don't support setting up timers based + * on a monotonically increasing clock. */ +#if defined ESX || (defined __x86_64__ && defined LINUX_DATAPATH) +#define CACHE_TIME 0 +#else +#define CACHE_TIME 1 +#endif + void time_disable_restart(void); void time_enable_restart(void); void time_postfork(void); |