On Sun, 2007-09-30 at 09:20 +0200, Ingo Molnar wrote: > * Jan Luebbe <[EMAIL PROTECTED]> wrote: > > From: Jan Lübbe <[EMAIL PROTECTED]> > > > > The new behaviour of CFS exposes a race which occurs if a switch is > > requested when vt_mode.mode is VT_PROCESS. > > > > The process with vc->vt_pid is signaled before vc->vt_newvt is set. This > > causes the switch to fail when triggered by the monitoing process > > because the target is still -1. > > > > Signed-off-by: Jan Lübbe <[EMAIL PROTECTED]> > > nifty! I'm wondering what the symptoms of this bug were - how did you > notice it? Also, i'm wondering how you managed to debug this - looks > quite hard to trigger this race, right? > > Acked-by: Ingo Molnar <[EMAIL PROTECTED]> > > Ingo
I'm currenly porting the OpenMoko patchset to 2.6.23-rc8. We are using psplash and kdrive. When booting, I got an error from psplash about being unable to switch consoles. Strangely, it was possible to start kdrive manually. So i set up qemu for kernel debugging, set some interesting breakpoints and then saw that it was scheduling away directly after the kill_pid. Then it was quite obvious. It was triggering every time, on the device and in qemu identically. Most people testing the RCs probably don't run psplash (or any other program which sets vt_mode.mode to VT_PROCESS), so it wasn't noticed earlier. Jan - 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/
