* Linus Torvalds <[EMAIL PROTECTED]> wrote: > But why does that happen? And why would the scheduler have *anything* > to do with this? No idea. Maybe timing. Maybe the time.c changes. > Dunno.
hm, Markus indicated that he tried the v2.6.21.6-cfsv19 patch, and that does not include the time.c change. Markus - does your kernel include the code below? (if yes, please revert it via patch -p1 -R ) Ingo Index: linux/kernel/time.c =================================================================== --- linux.orig/kernel/time.c +++ linux/kernel/time.c @@ -57,14 +57,17 @@ EXPORT_SYMBOL(sys_tz); */ asmlinkage long sys_time(time_t __user * tloc) { - time_t i; - struct timeval tv; + /* + * We read xtime.tv_sec atomically - it's updated + * atomically by update_wall_time(), so no need to + * even read-lock the xtime seqlock: + */ + time_t i = xtime.tv_sec; - do_gettimeofday(&tv); - i = tv.tv_sec; + smp_rmb(); /* sys_time() results are coherent */ if (tloc) { - if (put_user(i,tloc)) + if (put_user(i, tloc)) i = -EFAULT; } return i; @@ -373,6 +376,20 @@ void do_gettimeofday (struct timeval *tv tv->tv_sec = sec; tv->tv_usec = usec; + + /* + * Make sure xtime.tv_sec [returned by sys_time()] always + * follows the gettimeofday() result precisely. This + * condition is extremely unlikely, it can hit at most + * once per second: + */ + if (unlikely(xtime.tv_sec != tv->tv_sec)) { + unsigned long flags; + + write_seqlock_irqsave(&xtime_lock); + update_wall_time(); + write_seqlock_irqrestore(&xtime_lock); + } } EXPORT_SYMBOL(do_gettimeofday); - 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/