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[Qemu-devel] [PULL 41/49] cpus: use broadcast on qemu_pause_cond
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 41/49] cpus: use broadcast on qemu_pause_cond |
Date: |
Tue, 26 Jan 2016 14:47:13 +0100 |
From: "Dr. David Alan Gilbert" <address@hidden>
Jiri saw a hang on pause_all_vcpus called from postcopy_start,
where the cpus are all apparently stopped ('stopped' flag set)
but pause_all_vcpus is still stuck on a cond_wait on qemu_paused_cond.
We suspect this is happening if a qmp_stop is called at about the
same time as the postcopy code calls that pause_all_vcpus;
although they both should have the main lock held, Paolo spotted
the cond_wait unlocks the global lock so perhaps they both
could end up waiting at the same time?
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Reported-by: Jiri Denemark <address@hidden>
Message-Id: <address@hidden>
Cc: address@hidden
Signed-off-by: Paolo Bonzini <address@hidden>
---
cpus.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/cpus.c b/cpus.c
index ea29584..51f5ea4 100644
--- a/cpus.c
+++ b/cpus.c
@@ -986,7 +986,7 @@ static void qemu_wait_io_event_common(CPUState *cpu)
if (cpu->stop) {
cpu->stop = false;
cpu->stopped = true;
- qemu_cond_signal(&qemu_pause_cond);
+ qemu_cond_broadcast(&qemu_pause_cond);
}
flush_queued_work(cpu);
cpu->thread_kicked = false;
@@ -1387,7 +1387,7 @@ void cpu_stop_current(void)
current_cpu->stop = false;
current_cpu->stopped = true;
cpu_exit(current_cpu);
- qemu_cond_signal(&qemu_pause_cond);
+ qemu_cond_broadcast(&qemu_pause_cond);
}
}
--
1.8.3.1
- [Qemu-devel] [PULL 28/49] scripts/kvm/kvm_stat: Cleanup of Stats class, (continued)
- [Qemu-devel] [PULL 28/49] scripts/kvm/kvm_stat: Cleanup of Stats class, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 36/49] scripts/kvm/kvm_stat: Read event values as u64, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 31/49] scripts/kvm/kvm_stat: Group arch specific data, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 34/49] scripts/kvm/kvm_stat: Fix output formatting, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 33/49] scripts/kvm/kvm_stat: Make tui function a class, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 37/49] scripts/kvm/kvm_stat: Fix rlimit for unprivileged users, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 38/49] scripts/kvm/kvm_stat: Fixup filtering, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 32/49] scripts/kvm/kvm_stat: Remove unneeded X86_EXIT_REASONS, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 35/49] scripts/kvm/kvm_stat: Cleanup and pre-init perf_event_attr, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 40/49] scripts/kvm/kvm_stat: Add optparse description, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 41/49] cpus: use broadcast on qemu_pause_cond,
Paolo Bonzini <=
- [Qemu-devel] [PULL 39/49] scripts/kvm/kvm_stat: Add interactive filtering, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 43/49] nbd: add missed aio_context_acquire in nbd_export_new, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 42/49] memory: exit when hugepage allocation fails if mem-prealloc, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 45/49] scripts/dump-guest-memory.py: Make methods functions, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 46/49] scripts/dump-guest-memory.py: Improve python 3 compatibility, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 47/49] scripts/dump-guest-memory.py: Cleanup functions, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 44/49] scripts/dump-guest-memory.py: Move constants to the top, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 48/49] scripts/dump-guest-memory.py: Introduce multi-arch support, Paolo Bonzini, 2016/01/26
- [Qemu-devel] [PULL 49/49] scripts/dump-guest-memory.py: Fix module docstring, Paolo Bonzini, 2016/01/26
- Re: [Qemu-devel] [PULL 00/49] chardev, NBD, cpus, scripts/ changes for 2015-01-26, Peter Maydell, 2016/01/26