On Mon, Oct 20, 2008 at 02:13:39PM +0200, Ingo Molnar wrote: > > * Neil Horman <nhorman at tuxdriver.com> wrote: > > > Hey all- > > Theres a corner case in 32 bit x86 kdump at the moment. When > > the box panics via nmi, we call bust_spinlocks(1) to disable > > sensitivity to the console_sem (allowing us to print to the console in > > all cases), but we don't call crash_kexec, until after we call > > bust_spinlocks(0), which re-enables console_sem sensitivity. The > > result is that, if we get an nmi while the console_sem is held and > > kdump is configured, and we try to print something to the console > > during kdump shutdown (which we often do) we deadlock the box. The > > fix is to simply do what 64 bit die_nmi does which is to not call > > bust_spinlocks(0) until after we call crash_kexec. Patch below tested > > successfully by me: > > applied to tip/x86/urgent, thanks Neil! > Thanks, Ingo! > > dumpstack_32.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > would be nice to unify this code some more - to create a new > arch/x86/kernel/dumpstack.c and fill it in with die_nmi() as a > beginning? > Agreed, I'll try look into that as soon as I have some free time. Regards Neil > Ingo > -- /**************************************************** * Neil Horman <nhorman at tuxdriver.com> * Software Engineer, Red Hat ****************************************************/
