| Message ID | 1350663115-11373-1-git-send-email-sasha.levin@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 19, 2012 at 12:11:55PM -0400, Sasha Levin wrote: > KVM_PV_REASON_PAGE_NOT_PRESENT kicks cpu out of idleness, but we haven't > marked that spot as an exit from idleness. > > Not doing so can cause RCU warnings such as: > > [ 732.788386] =============================== > [ 732.789803] [ INFO: suspicious RCU usage. ] > [ 732.790032] 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 Tainted: G W > [ 732.790032] ------------------------------- > [ 732.790032] include/linux/rcupdate.h:738 rcu_read_lock() used illegally while idle! > [ 732.790032] > [ 732.790032] other info that might help us debug this: > [ 732.790032] > [ 732.790032] > [ 732.790032] RCU used illegally from idle CPU! > [ 732.790032] rcu_scheduler_active = 1, debug_locks = 1 > [ 732.790032] RCU used illegally from extended quiescent state! > [ 732.790032] 2 locks held by trinity-child31/8252: > [ 732.790032] #0: (&rq->lock){-.-.-.}, at: [<ffffffff83a67528>] __schedule+0x178/0x8f0 > [ 732.790032] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff81152bde>] cpuacct_charge+0xe/0x200 > [ 732.790032] > [ 732.790032] stack backtrace: > [ 732.790032] Pid: 8252, comm: trinity-child31 Tainted: G W 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 > [ 732.790032] Call Trace: > [ 732.790032] [<ffffffff8118266b>] lockdep_rcu_suspicious+0x10b/0x120 > [ 732.790032] [<ffffffff81152c60>] cpuacct_charge+0x90/0x200 > [ 732.790032] [<ffffffff81152bde>] ? cpuacct_charge+0xe/0x200 > [ 732.790032] [<ffffffff81158093>] update_curr+0x1a3/0x270 > [ 732.790032] [<ffffffff81158a6a>] dequeue_entity+0x2a/0x210 > [ 732.790032] [<ffffffff81158ea5>] dequeue_task_fair+0x45/0x130 > [ 732.790032] [<ffffffff8114ae29>] dequeue_task+0x89/0xa0 > [ 732.790032] [<ffffffff8114bb9e>] deactivate_task+0x1e/0x20 > [ 732.790032] [<ffffffff83a67c29>] __schedule+0x879/0x8f0 > [ 732.790032] [<ffffffff8117e20d>] ? trace_hardirqs_off+0xd/0x10 > [ 732.790032] [<ffffffff810a37a5>] ? kvm_async_pf_task_wait+0x1d5/0x2b0 > [ 732.790032] [<ffffffff83a67cf5>] schedule+0x55/0x60 > [ 732.790032] [<ffffffff810a37c4>] kvm_async_pf_task_wait+0x1f4/0x2b0 > [ 732.790032] [<ffffffff81139e50>] ? abort_exclusive_wait+0xb0/0xb0 > [ 732.790032] [<ffffffff81139c25>] ? prepare_to_wait+0x25/0x90 > [ 732.790032] [<ffffffff810a3a66>] do_async_page_fault+0x56/0xa0 > [ 732.790032] [<ffffffff83a6a6e8>] async_page_fault+0x28/0x30 > > Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > --- > arch/x86/kernel/kvm.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index b3e5e51..4180a87 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -247,7 +247,10 @@ do_async_page_fault(struct pt_regs *regs, unsigned long error_code) > break; > case KVM_PV_REASON_PAGE_NOT_PRESENT: > /* page is swapped out by the host. */ > + rcu_irq_enter(); > + exit_idle(); > kvm_async_pf_task_wait((u32)read_cr2()); > + rcu_irq_exit(); > break; > case KVM_PV_REASON_PAGE_READY: > rcu_irq_enter(); > -- > 1.7.12.3 > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Oct 19, 2012 at 12:11:55PM -0400, Sasha Levin wrote: > KVM_PV_REASON_PAGE_NOT_PRESENT kicks cpu out of idleness, but we haven't > marked that spot as an exit from idleness. > > Not doing so can cause RCU warnings such as: > > [ 732.788386] =============================== > [ 732.789803] [ INFO: suspicious RCU usage. ] > [ 732.790032] 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 Tainted: G W > [ 732.790032] ------------------------------- > [ 732.790032] include/linux/rcupdate.h:738 rcu_read_lock() used illegally while idle! > [ 732.790032] > [ 732.790032] other info that might help us debug this: > [ 732.790032] > [ 732.790032] > [ 732.790032] RCU used illegally from idle CPU! > [ 732.790032] rcu_scheduler_active = 1, debug_locks = 1 > [ 732.790032] RCU used illegally from extended quiescent state! > [ 732.790032] 2 locks held by trinity-child31/8252: > [ 732.790032] #0: (&rq->lock){-.-.-.}, at: [<ffffffff83a67528>] __schedule+0x178/0x8f0 > [ 732.790032] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff81152bde>] cpuacct_charge+0xe/0x200 > [ 732.790032] > [ 732.790032] stack backtrace: > [ 732.790032] Pid: 8252, comm: trinity-child31 Tainted: G W 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 > [ 732.790032] Call Trace: > [ 732.790032] [<ffffffff8118266b>] lockdep_rcu_suspicious+0x10b/0x120 > [ 732.790032] [<ffffffff81152c60>] cpuacct_charge+0x90/0x200 > [ 732.790032] [<ffffffff81152bde>] ? cpuacct_charge+0xe/0x200 > [ 732.790032] [<ffffffff81158093>] update_curr+0x1a3/0x270 > [ 732.790032] [<ffffffff81158a6a>] dequeue_entity+0x2a/0x210 > [ 732.790032] [<ffffffff81158ea5>] dequeue_task_fair+0x45/0x130 > [ 732.790032] [<ffffffff8114ae29>] dequeue_task+0x89/0xa0 > [ 732.790032] [<ffffffff8114bb9e>] deactivate_task+0x1e/0x20 > [ 732.790032] [<ffffffff83a67c29>] __schedule+0x879/0x8f0 > [ 732.790032] [<ffffffff8117e20d>] ? trace_hardirqs_off+0xd/0x10 > [ 732.790032] [<ffffffff810a37a5>] ? kvm_async_pf_task_wait+0x1d5/0x2b0 > [ 732.790032] [<ffffffff83a67cf5>] schedule+0x55/0x60 > [ 732.790032] [<ffffffff810a37c4>] kvm_async_pf_task_wait+0x1f4/0x2b0 > [ 732.790032] [<ffffffff81139e50>] ? abort_exclusive_wait+0xb0/0xb0 > [ 732.790032] [<ffffffff81139c25>] ? prepare_to_wait+0x25/0x90 > [ 732.790032] [<ffffffff810a3a66>] do_async_page_fault+0x56/0xa0 > [ 732.790032] [<ffffffff83a6a6e8>] async_page_fault+0x28/0x30 > > Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Gleb Natapov <gleb@redhat.com> > --- > arch/x86/kernel/kvm.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index b3e5e51..4180a87 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -247,7 +247,10 @@ do_async_page_fault(struct pt_regs *regs, unsigned long error_code) > break; > case KVM_PV_REASON_PAGE_NOT_PRESENT: > /* page is swapped out by the host. */ > + rcu_irq_enter(); > + exit_idle(); > kvm_async_pf_task_wait((u32)read_cr2()); > + rcu_irq_exit(); > break; > case KVM_PV_REASON_PAGE_READY: > rcu_irq_enter(); > -- > 1.7.12.3 -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 10/19/2012 06:11 PM, Sasha Levin wrote: > KVM_PV_REASON_PAGE_NOT_PRESENT kicks cpu out of idleness, but we haven't > marked that spot as an exit from idleness. > > Not doing so can cause RCU warnings such as: > > [ 732.788386] =============================== > [ 732.789803] [ INFO: suspicious RCU usage. ] > [ 732.790032] 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 Tainted: G W > [ 732.790032] ------------------------------- > [ 732.790032] include/linux/rcupdate.h:738 rcu_read_lock() used illegally while idle! > [ 732.790032] > [ 732.790032] other info that might help us debug this: > [ 732.790032] > [ 732.790032] > [ 732.790032] RCU used illegally from idle CPU! > [ 732.790032] rcu_scheduler_active = 1, debug_locks = 1 > [ 732.790032] RCU used illegally from extended quiescent state! > [ 732.790032] 2 locks held by trinity-child31/8252: > [ 732.790032] #0: (&rq->lock){-.-.-.}, at: [<ffffffff83a67528>] __schedule+0x178/0x8f0 > [ 732.790032] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff81152bde>] cpuacct_charge+0xe/0x200 > [ 732.790032] > [ 732.790032] stack backtrace: > [ 732.790032] Pid: 8252, comm: trinity-child31 Tainted: G W 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 > [ 732.790032] Call Trace: > [ 732.790032] [<ffffffff8118266b>] lockdep_rcu_suspicious+0x10b/0x120 > [ 732.790032] [<ffffffff81152c60>] cpuacct_charge+0x90/0x200 > [ 732.790032] [<ffffffff81152bde>] ? cpuacct_charge+0xe/0x200 > [ 732.790032] [<ffffffff81158093>] update_curr+0x1a3/0x270 > [ 732.790032] [<ffffffff81158a6a>] dequeue_entity+0x2a/0x210 > [ 732.790032] [<ffffffff81158ea5>] dequeue_task_fair+0x45/0x130 > [ 732.790032] [<ffffffff8114ae29>] dequeue_task+0x89/0xa0 > [ 732.790032] [<ffffffff8114bb9e>] deactivate_task+0x1e/0x20 > [ 732.790032] [<ffffffff83a67c29>] __schedule+0x879/0x8f0 > [ 732.790032] [<ffffffff8117e20d>] ? trace_hardirqs_off+0xd/0x10 > [ 732.790032] [<ffffffff810a37a5>] ? kvm_async_pf_task_wait+0x1d5/0x2b0 > [ 732.790032] [<ffffffff83a67cf5>] schedule+0x55/0x60 > [ 732.790032] [<ffffffff810a37c4>] kvm_async_pf_task_wait+0x1f4/0x2b0 > [ 732.790032] [<ffffffff81139e50>] ? abort_exclusive_wait+0xb0/0xb0 > [ 732.790032] [<ffffffff81139c25>] ? prepare_to_wait+0x25/0x90 > [ 732.790032] [<ffffffff810a3a66>] do_async_page_fault+0x56/0xa0 > [ 732.790032] [<ffffffff83a6a6e8>] async_page_fault+0x28/0x30 Thanks, applied to master for 3.7.
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index b3e5e51..4180a87 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -247,7 +247,10 @@ do_async_page_fault(struct pt_regs *regs, unsigned long error_code) break; case KVM_PV_REASON_PAGE_NOT_PRESENT: /* page is swapped out by the host. */ + rcu_irq_enter(); + exit_idle(); kvm_async_pf_task_wait((u32)read_cr2()); + rcu_irq_exit(); break; case KVM_PV_REASON_PAGE_READY: rcu_irq_enter();
KVM_PV_REASON_PAGE_NOT_PRESENT kicks cpu out of idleness, but we haven't marked that spot as an exit from idleness. Not doing so can cause RCU warnings such as: [ 732.788386] =============================== [ 732.789803] [ INFO: suspicious RCU usage. ] [ 732.790032] 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 Tainted: G W [ 732.790032] ------------------------------- [ 732.790032] include/linux/rcupdate.h:738 rcu_read_lock() used illegally while idle! [ 732.790032] [ 732.790032] other info that might help us debug this: [ 732.790032] [ 732.790032] [ 732.790032] RCU used illegally from idle CPU! [ 732.790032] rcu_scheduler_active = 1, debug_locks = 1 [ 732.790032] RCU used illegally from extended quiescent state! [ 732.790032] 2 locks held by trinity-child31/8252: [ 732.790032] #0: (&rq->lock){-.-.-.}, at: [<ffffffff83a67528>] __schedule+0x178/0x8f0 [ 732.790032] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff81152bde>] cpuacct_charge+0xe/0x200 [ 732.790032] [ 732.790032] stack backtrace: [ 732.790032] Pid: 8252, comm: trinity-child31 Tainted: G W 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 [ 732.790032] Call Trace: [ 732.790032] [<ffffffff8118266b>] lockdep_rcu_suspicious+0x10b/0x120 [ 732.790032] [<ffffffff81152c60>] cpuacct_charge+0x90/0x200 [ 732.790032] [<ffffffff81152bde>] ? cpuacct_charge+0xe/0x200 [ 732.790032] [<ffffffff81158093>] update_curr+0x1a3/0x270 [ 732.790032] [<ffffffff81158a6a>] dequeue_entity+0x2a/0x210 [ 732.790032] [<ffffffff81158ea5>] dequeue_task_fair+0x45/0x130 [ 732.790032] [<ffffffff8114ae29>] dequeue_task+0x89/0xa0 [ 732.790032] [<ffffffff8114bb9e>] deactivate_task+0x1e/0x20 [ 732.790032] [<ffffffff83a67c29>] __schedule+0x879/0x8f0 [ 732.790032] [<ffffffff8117e20d>] ? trace_hardirqs_off+0xd/0x10 [ 732.790032] [<ffffffff810a37a5>] ? kvm_async_pf_task_wait+0x1d5/0x2b0 [ 732.790032] [<ffffffff83a67cf5>] schedule+0x55/0x60 [ 732.790032] [<ffffffff810a37c4>] kvm_async_pf_task_wait+0x1f4/0x2b0 [ 732.790032] [<ffffffff81139e50>] ? abort_exclusive_wait+0xb0/0xb0 [ 732.790032] [<ffffffff81139c25>] ? prepare_to_wait+0x25/0x90 [ 732.790032] [<ffffffff810a3a66>] do_async_page_fault+0x56/0xa0 [ 732.790032] [<ffffffff83a6a6e8>] async_page_fault+0x28/0x30 Signed-off-by: Sasha Levin <sasha.levin@oracle.com> --- arch/x86/kernel/kvm.c | 3 +++ 1 file changed, 3 insertions(+)