From: Thomas Gleixner Date: Wed, 11 Sep 2024 13:17:42 +0000 (+0200) Subject: ntp: Read reference time only once X-Git-Tag: v6.13-rc1~171^2~125 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=136bccbc2e78d3cd0bd8831e4c5a4509c0ddd945;p=thirdparty%2Fkernel%2Fstable.git ntp: Read reference time only once The reference time is required twice in ntp_update_offset(). It will not change in the meantime as the calling code holds the timekeeper lock. Read it only once and store it into a local variable. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Acked-by: John Stultz Link: https://lore.kernel.org/all/20240911-devel-anna-maria-b4-timers-ptp-ntp-v1-6-2d52f4e13476@linutronix.de --- diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 905b0216b12dc..0bfd07de202a5 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -283,9 +283,8 @@ static inline s64 ntp_update_offset_fll(s64 offset64, long secs) static void ntp_update_offset(long offset) { - s64 freq_adj; - s64 offset64; - long secs; + s64 freq_adj, offset64; + long secs, real_secs; if (!(time_status & STA_PLL)) return; @@ -303,11 +302,12 @@ static void ntp_update_offset(long offset) * Select how the frequency is to be controlled * and in which mode (PLL or FLL). */ - secs = (long)(__ktime_get_real_seconds() - time_reftime); + real_secs = __ktime_get_real_seconds(); + secs = (long)(real_secs - time_reftime); if (unlikely(time_status & STA_FREQHOLD)) secs = 0; - time_reftime = __ktime_get_real_seconds(); + time_reftime = real_secs; offset64 = offset; freq_adj = ntp_update_offset_fll(offset64, secs);