Re: [PATCH][RFC v4] timekeeping: ignore the bogus sleep time if pm_trace is enabled
From: Oliver Neukum <oneukum@suse.com>
Date: 2016-08-18 10:41:44
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lkml
On Thu, 2016-08-18 at 18:43 +0800, Chen Yu wrote:
Previously we encountered some memory overflow issues due to the bogus sleep time brought by inconsistent rtc, which is triggered when pm_trace is enabled, please refer to: https://patchwork.kernel.org/patch/9286365/ It's improper in the first place to call __timekeeping_inject_sleeptime() in case that pm_trace is enabled simply because that "hash" time value will wreckage the timekeeping subsystem.
Hi, do you know since when this bug exists?
quoted hunk ↗ jump to hunk
/**@@ -1662,6 +1668,12 @@ void timekeeping_resume(void) } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) { ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time); sleeptime_injected = true; + /* + * If rtc is used as persist clock thus it + * would be bogus when pm_trace is enabled. + */ + if (!persistent_clock_is_usable()) + sleeptime_injected = false; } if (sleeptime_injected)
How about sleeptime_injected = persistent_clock_is_usable(); Regards Oliver