2.6.23-stable review patch. If anyone has any objections, please let us know.
------------------ From: David P. Reed <[EMAIL PROTECTED]> patch fa6a1a554b50cbb7763f6907e6fef927ead480d9 in mainline. ntp: fix typo that makes sync_cmos_clock erratic Fix a typo in ntp.c that has caused updating of the persistent (RTC) clock when synced to NTP to behave erratically. When debugging a freeze that arises on my AMD64 machines when I run the ntpd service, I added a number of printk's to monitor the sync_cmos_clock procedure. I discovered that it was not syncing to cmos RTC every 11 minutes as documented, but instead would keep trying every second for hours at a time. The reason turned out to be a typo in sync_cmos_clock, where it attempts to ensure that update_persistent_clock is called very close to 500 msec. after a 1 second boundary (required by the PC RTC's spec). That typo referred to "xtime" in one spot, rather than "now", which is derived from "xtime" but not equal to it. This makes the test erratic, creating a "coin-flip" that decides when update_persistent_clock is called - when it is called, which is rarely, it may be at any time during the one second period, rather than close to 500 msec, so the value written is needlessly incorrect, too. Signed-off-by: David P. Reed <[EMAIL PROTECTED]> Signed-off-by: Thomas Gleixner <[EMAIL PROTECTED]> Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]> Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]> --- kernel/time/ntp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -205,7 +205,7 @@ static void sync_cmos_clock(unsigned lon return; getnstimeofday(&now); - if (abs(xtime.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) + if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) fail = update_persistent_clock(now); next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec; -- - 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/