David, On Mon, 12 Nov 2007, David P. Reed wrote:
> From: David P. Reed > > Fix two bugs in arch/x86/kernel/time_64.c that affect the x86_64 kernel. 1) a > repeatable hard freeze due to interrupts when the ntpd service calls > update_persistent_clock(), 2) potentially unstable PC RTC timer values when > timer is read. 1) Please send separate patches for separate problems. 2) Your patch is white space damaged and does not apply. Please run it through scripts/checkpatch.pl before submitting, maybe send it to yourself first and verify that it applies correctly. > Signed-off-by: David P. Reed <[EMAIL PROTECTED]> > --- > More explanation: > 1) A repeatable but randomly timed freeze has been happening in Fedora 6 and 7 > for the last year, whenever I run the ntpd service on my AMD64x2 HP Pavilion > dv9000z laptop. This freeze is due to the use of spin_lock(&rtc_lock) under > the assumption (per a bad comment) that set_rtc_mmss is called only with > interrupts disabled. The call from ntp.c to update_persistent_clock is made > with interrupts enabled. Good catch. > 2) the use of an incorrect technique for reading the standard PC RTC timer, > which is documented to "disconnect" time registers from the bus while updates > are in progress. The use of UIP flag while interrupts are disabled to protect > a 244 microsecond window is one of the Motorola spec sheet's documented ways > to read the RTC time registers reliably. I realize that not all "clones" of > the of the what ? Also put the detailed description into the patch comment, please. > The patch updates the misleading comments and minimizes the amount of time > that the kernel disables interrupts. > > I have thoroughly tested this patch on a number of x86_64 machines with > various numbers of cores and chipsets, using 2.6.24rc2 kernel source. Note > that while testing the ntp code I found another bug in kernel/time/ntp.c which > is independent of this fix - neither patch requires the other. > > If possible, I'd love to see the patch merged with 2.6.24, and even with > 2.6.23. Care to resend ? Thanks, tglx - 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/