Commit-ID: b0deca2e0270135f797e81bdb0743e50fd1dc58d Gitweb: http://git.kernel.org/tip/b0deca2e0270135f797e81bdb0743e50fd1dc58d Author: Dimitri Sivanich <sivanich@xxxxxxx> AuthorDate: Fri, 17 Feb 2012 08:16:41 -0600 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Mon, 20 Feb 2012 09:07:56 +0100 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 <sivanich@xxxxxxx> Cc: John Stultz <johnstul@xxxxxxxxxx> Cc: Jack Steiner <steiner@xxxxxxx> Link: http://lkml.kernel.org/r/20120217141641.GA28063@xxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- 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 9f29a01..5032e0d 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); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html