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| author | Paolo Bonzini <pbonzini@redhat.com> | 2013-09-25 13:53:07 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2013-09-30 09:21:51 +0200 |
| commit | 2f303b74a62fb74983c0a66e2df353be963c527c (patch) | |
| tree | 430c287a89d709fb9d497d0c2a5a33acc434b020 /Documentation/virtual | |
| parent | KVM: protect kvm_usage_count with its own spinlock (diff) | |
| download | linux-2f303b74a62fb74983c0a66e2df353be963c527c.tar.xz linux-2f303b74a62fb74983c0a66e2df353be963c527c.zip | |
KVM: Convert kvm_lock back to non-raw spinlock
In commit e935b8372cf8 ("KVM: Convert kvm_lock to raw_spinlock"),
the kvm_lock was made a raw lock. However, the kvm mmu_shrink()
function tries to grab the (non-raw) mmu_lock within the scope of
the raw locked kvm_lock being held. This leads to the following:
BUG: sleeping function called from invalid context at kernel/rtmutex.c:659
in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0
Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm]
Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt
Call Trace:
[<ffffffff8106f2ad>] __might_sleep+0xfd/0x160
[<ffffffff817d8d64>] rt_spin_lock+0x24/0x50
[<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm]
[<ffffffff8111455d>] shrink_slab+0x17d/0x3a0
[<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260
[<ffffffff8111824a>] balance_pgdat+0x54a/0x730
[<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0
[<ffffffff811185bf>] kswapd+0x18f/0x490
[<ffffffff81070961>] ? get_parent_ip+0x11/0x50
[<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50
[<ffffffff81118430>] ? balance_pgdat+0x730/0x730
[<ffffffff81060d2b>] kthread+0xdb/0xe0
[<ffffffff8106e122>] ? finish_task_switch+0x52/0x100
[<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10
[<ffffffff81060c50>] ? __init_kthread_worker+0x
After the previous patch, kvm_lock need not be a raw spinlock anymore,
so change it back.
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virtual')
| -rw-r--r-- | Documentation/virtual/kvm/locking.txt | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index ba9e1c2150c2..f8869410d40c 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -132,7 +132,7 @@ See the comments in spte_has_volatile_bits() and mmu_spte_update(). ------------ Name: kvm_lock -Type: raw_spinlock +Type: spinlock_t Arch: any Protects: - vm_list |