| Message ID | 1299077834-27946-1-git-send-email-stefan.bader@canonical.com |
|---|---|
| State | Accepted |
| Delegated to: | Tim Gardner |
| Headers | show |
On 03/02/2011 03:57 PM, Stefan Bader wrote: > SRU Justification: > > Impact: On reboot or shutdown the current Xen code does try to stop other > CPUs. However the IPI communication is disabled already at that point. > So issuing a reboot or shutdown from within an instance with multiple > vcpus hangs. > > Fix: Cherry pick of an upstream patch (added around 2.6.37) removes the > attempt to stop other CPUs. > > Testcase: From within an EC2 instance, call "sudo reboot". Instance never > comes up again. With the patch applied it does. > > -Stefan Forgot to mention: this is also on the 2.6.35-longterm tree.
On 03/02/2011 08:13 AM, Stefan Bader wrote: > On 03/02/2011 03:57 PM, Stefan Bader wrote: >> SRU Justification: >> >> Impact: On reboot or shutdown the current Xen code does try to stop other >> CPUs. However the IPI communication is disabled already at that point. >> So issuing a reboot or shutdown from within an instance with multiple >> vcpus hangs. >> >> Fix: Cherry pick of an upstream patch (added around 2.6.37) removes the >> attempt to stop other CPUs. >> >> Testcase: From within an EC2 instance, call "sudo reboot". Instance never >> comes up again. With the patch applied it does. >> >> -Stefan > > Forgot to mention: this is also on the 2.6.35-longterm tree. > Acked-by: Tim Gardner <tim.gardner@canonical.com>
On 03/02/2011 06:57 AM, Stefan Bader wrote: > SRU Justification: > > Impact: On reboot or shutdown the current Xen code does try to stop other > CPUs. However the IPI communication is disabled already at that point. > So issuing a reboot or shutdown from within an instance with multiple > vcpus hangs. > > Fix: Cherry pick of an upstream patch (added around 2.6.37) removes the > attempt to stop other CPUs. > > Testcase: From within an EC2 instance, call "sudo reboot". Instance never > comes up again. With the patch applied it does. > > -Stefan > > --- > > From bf8e8b6da4821b59ea162eec16e05f3a6d8a0f9a Mon Sep 17 00:00:00 2001 > From: Jeremy Fitzhardinge<jeremy.fitzhardinge@citrix.com> > Date: Mon, 29 Nov 2010 14:16:53 -0800 > Subject: [PATCH] xen: don't bother to stop other cpus on shutdown/reboot > > Xen will shoot all the VCPUs when we do a shutdown hypercall, so there's > no need to do it manually. > > In any case it will fail because all the IPI irqs have been pulled > down by this point, so the cross-CPU calls will simply hang forever. > > Until change 76fac077db6b34e2c6383a7b4f3f4f7b7d06d8ce the function calls > were not synchronously waited for, so this wasn't apparent. However after > that change the calls became synchronous leading to a hang on shutdown > on multi-VCPU guests. > > Signed-off-by: Jeremy Fitzhardinge<jeremy.fitzhardinge@citrix.com> > Cc: Stable Kernel<stable@kernel.org> > Cc: Alok Kataria<akataria@vmware.com> > > BugLink: http://bugs.launchpad.net/bugs/727814 > > (cherry-picked from commit 31e323cca9d5c8afd372976c35a5d46192f540d1 upstream) > Signed-off-by: Stefan Bader<stefan.bader@canonical.com> > --- > arch/x86/xen/enlighten.c | 4 ---- > 1 files changed, 0 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c > index 6f6cd65..42c2d5f 100644 > --- a/arch/x86/xen/enlighten.c > +++ b/arch/x86/xen/enlighten.c > @@ -1022,10 +1022,6 @@ static void xen_reboot(int reason) > { > struct sched_shutdown r = { .reason = reason }; > > -#ifdef CONFIG_SMP > - stop_other_cpus(); > -#endif > - > if (HYPERVISOR_sched_op(SCHEDOP_shutdown,&r)) > BUG(); > } Acked-by: Brad Figg <brad.figg@canonical.com>
On 03/02/2011 07:57 AM, Stefan Bader wrote: > SRU Justification: > > Impact: On reboot or shutdown the current Xen code does try to stop other > CPUs. However the IPI communication is disabled already at that point. > So issuing a reboot or shutdown from within an instance with multiple > vcpus hangs. > > Fix: Cherry pick of an upstream patch (added around 2.6.37) removes the > attempt to stop other CPUs. > > Testcase: From within an EC2 instance, call "sudo reboot". Instance never > comes up again. With the patch applied it does. > > -Stefan > > --- > > From bf8e8b6da4821b59ea162eec16e05f3a6d8a0f9a Mon Sep 17 00:00:00 2001 > From: Jeremy Fitzhardinge<jeremy.fitzhardinge@citrix.com> > Date: Mon, 29 Nov 2010 14:16:53 -0800 > Subject: [PATCH] xen: don't bother to stop other cpus on shutdown/reboot > > Xen will shoot all the VCPUs when we do a shutdown hypercall, so there's > no need to do it manually. > > In any case it will fail because all the IPI irqs have been pulled > down by this point, so the cross-CPU calls will simply hang forever. > > Until change 76fac077db6b34e2c6383a7b4f3f4f7b7d06d8ce the function calls > were not synchronously waited for, so this wasn't apparent. However after > that change the calls became synchronous leading to a hang on shutdown > on multi-VCPU guests. > > Signed-off-by: Jeremy Fitzhardinge<jeremy.fitzhardinge@citrix.com> > Cc: Stable Kernel<stable@kernel.org> > Cc: Alok Kataria<akataria@vmware.com> > > BugLink: http://bugs.launchpad.net/bugs/727814 > > (cherry-picked from commit 31e323cca9d5c8afd372976c35a5d46192f540d1 upstream) > Signed-off-by: Stefan Bader<stefan.bader@canonical.com> > --- > arch/x86/xen/enlighten.c | 4 ---- > 1 files changed, 0 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c > index 6f6cd65..42c2d5f 100644 > --- a/arch/x86/xen/enlighten.c > +++ b/arch/x86/xen/enlighten.c > @@ -1022,10 +1022,6 @@ static void xen_reboot(int reason) > { > struct sched_shutdown r = { .reason = reason }; > > -#ifdef CONFIG_SMP > - stop_other_cpus(); > -#endif > - > if (HYPERVISOR_sched_op(SCHEDOP_shutdown,&r)) > BUG(); > } applied
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 6f6cd65..42c2d5f 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1022,10 +1022,6 @@ static void xen_reboot(int reason) { struct sched_shutdown r = { .reason = reason }; -#ifdef CONFIG_SMP - stop_other_cpus(); -#endif - if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r)) BUG(); }