diff options
| author | Dimitri Sivanich <[email protected]> | 2012-02-17 08:16:41 -0600 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2012-02-20 09:07:56 +0100 |
| commit | b0deca2e0270135f797e81bdb0743e50fd1dc58d (patch) | |
| tree | b5f43e3a30e0d5b663d38c571a1e55978df59061 | |
| parent | b01543dfe67bb1d191998e90d20534dc354de059 (diff) | |
x86/UV: Lower UV rtc clocksource rating
Lower the rating of the UV rtc clocksource to just below that of
the tsc, to improve performance.
Reading the tsc clocksource has lower latency than reading the
rtc, so favor it in situations where it is synchronized and
stable. When the tsc is unsynchronized, the rtc needs to be the
chosen clocksource.
Signed-off-by: Dimitri Sivanich <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Jack Steiner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | arch/x86/platform/uv/uv_time.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c index 9f29a01ee1b3..5032e0d19b86 100644 --- a/arch/x86/platform/uv/uv_time.c +++ b/arch/x86/platform/uv/uv_time.c @@ -37,7 +37,7 @@ static void uv_rtc_timer_setup(enum clock_event_mode, static struct clocksource clocksource_uv = { .name = RTC_NAME, - .rating = 400, + .rating = 299, .read = uv_read_rtc, .mask = (cycle_t)UVH_RTC_REAL_TIME_CLOCK_MASK, .flags = CLOCK_SOURCE_IS_CONTINUOUS, @@ -379,10 +379,6 @@ static __init int uv_rtc_setup_clock(void) if (!is_uv_system()) return -ENODEV; - /* If single blade, prefer tsc */ - if (uv_num_possible_blades() == 1) - clocksource_uv.rating = 250; - rc = clocksource_register_hz(&clocksource_uv, sn_rtc_cycles_per_second); if (rc) printk(KERN_INFO "UV RTC clocksource failed rc %d\n", rc); |