Ingo suggested that the timekeeping debugging variables recently added should not be global, and should be tied to the timekeeper's read_base.
Thus this patch implements that suggestion. This version is differnet from the earlier versions as it keeps the variables in the timekeeper structure rather then in the tkr. Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Prarit Bhargava <[email protected]> Cc: Richard Cochran <[email protected]> Signed-off-by: John Stultz <[email protected]> --- include/linux/timekeeper_internal.h | 15 +++++++++++++++ kernel/time/timekeeping.c | 33 +++++++++++---------------------- 2 files changed, 26 insertions(+), 22 deletions(-) diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index 6f8276a..35007b2 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -61,6 +61,9 @@ struct tk_read_base { * shifted nano seconds. * @ntp_error_shift: Shift conversion between clock shifted nano seconds and * ntp shifted nano seconds. + * @last_warning: Warning ratelimiter (DEBUG_TIMEKEEPING) + * @underflow_seen: Underflow warning flag (DEBUG_TIMEKEEPING) + * @overflow_seen: Overflow warning flag (DEBUG_TIMEKEEPING) * * Note: For timespec(64) based interfaces wall_to_monotonic is what * we need to add to xtime (or xtime corrected for sub jiffie times) @@ -106,6 +109,18 @@ struct timekeeper { s64 ntp_error; u32 ntp_error_shift; u32 ntp_err_mult; +#ifdef CONFIG_DEBUG_TIMEKEEPING + long last_warning; + /* + * These simple flag variables are managed + * without locks, which is racy, but ok since + * we don't really care about being super + * precise about how many events were seen, + * just that a problem was observed. + */ + int underflow_seen; + int overflow_seen; +#endif }; #ifdef CONFIG_GENERIC_TIME_VSYSCALL diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 85d3763..2f10b65 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -118,18 +118,6 @@ static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta) #ifdef CONFIG_DEBUG_TIMEKEEPING #define WARNING_FREQ (HZ*300) /* 5 minute rate-limiting */ -/* - * These simple flag variables are managed - * without locks, which is racy, but ok since - * we don't really care about being super - * precise about how many events were seen, - * just that a problem was observed. - */ -static int timekeeping_underflow_seen; -static int timekeeping_overflow_seen; - -/* last_warning is only modified under the timekeeping lock */ -static long timekeeping_last_warning; static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset) { @@ -149,29 +137,30 @@ static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset) } } - if (timekeeping_underflow_seen) { - if (jiffies - timekeeping_last_warning > WARNING_FREQ) { + if (tk->underflow_seen) { + if (jiffies - tk->last_warning > WARNING_FREQ) { printk_deferred("WARNING: Underflow in clocksource '%s' observed, time update ignored.\n", name); printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); printk_deferred(" Your kernel is probably still fine.\n"); - timekeeping_last_warning = jiffies; + tk->last_warning = jiffies; } - timekeeping_underflow_seen = 0; + tk->underflow_seen = 0; } - if (timekeeping_overflow_seen) { - if (jiffies - timekeeping_last_warning > WARNING_FREQ) { + if (tk->overflow_seen) { + if (jiffies - tk->last_warning > WARNING_FREQ) { printk_deferred("WARNING: Overflow in clocksource '%s' observed, time update capped.\n", name); printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); printk_deferred(" Your kernel is probably still fine.\n"); - timekeeping_last_warning = jiffies; + tk->last_warning = jiffies; } - timekeeping_overflow_seen = 0; + tk->overflow_seen = 0; } } static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr) { + struct timekeeper *tk = &tk_core.timekeeper; cycle_t now, last, mask, max, delta; unsigned int seq; @@ -197,13 +186,13 @@ static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr) * mask-relative negative values. */ if (unlikely((~delta & mask) < (mask >> 3))) { - timekeeping_underflow_seen = 1; + tk->underflow_seen = 1; delta = 0; } /* Cap delta value to the max_cycles values to avoid mult overflows */ if (unlikely(delta > max)) { - timekeeping_overflow_seen = 1; + tk->overflow_seen = 1; delta = tkr->clock->max_cycles; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
