From 302f1eeb80706fb10067efedb1279fa3f85ddda2 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Wed, 25 Jan 2017 20:59:15 +0000 Subject: [time] Allow timer to be selected at runtime Allow the active timer (providing udelay() and currticks()) to be selected at runtime based on probing during the INIT_EARLY stage of initialisation. TICKS_PER_SEC is now a fixed compile-time constant for all builds, and is independent of the underlying clock tick rate. We choose the value 1024 to allow multiplications and divisions on seconds to be converted to bit shifts. TICKS_PER_MS is defined as 1, allowing multiplications and divisions on milliseconds to be omitted entirely. The 2% inaccuracy in this definition is negligible when using the standard BIOS timer (running at around 18.2Hz). TIMER_RDTSC now checks for a constant TSC before claiming to be a usable timer. (This timer can be tested in KVM via the command-line option "-cpu host,+invtsc".) Signed-off-by: Michael Brown --- src/hci/commands/time_cmd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/hci') diff --git a/src/hci/commands/time_cmd.c b/src/hci/commands/time_cmd.c index d1dd49ca..08148bf3 100644 --- a/src/hci/commands/time_cmd.c +++ b/src/hci/commands/time_cmd.c @@ -68,7 +68,7 @@ static int time_exec ( int argc, char **argv ) { start = currticks(); rc = execv ( argv[1], argv + 1 ); elapsed = ( currticks() - start ); - decisecs = ( 10 * elapsed / ticks_per_sec() ); + decisecs = ( 10 * elapsed / TICKS_PER_SEC ); printf ( "%s: %d.%ds\n", argv[0], ( decisecs / 10 ), ( decisecs % 10 ) ); -- cgit v1.2.3-55-g7522