From: Paolo Bonzini <pbonzini@redhat.com>
To: "Gonglei (Arei)" <arei.gonglei@huawei.com>,
"Wubin (H)" <wu.wubin@huawei.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Cc: "kwolf@redhat.com" <kwolf@redhat.com>,
"Zhangmin (Rudy)" <rudy.zhangmin@huawei.com>,
"Huangpeng (Peter)" <peter.huangpeng@huawei.com>,
"stefanha@redhat.com" <stefanha@redhat.com>
Subject: Re: [Qemu-devel] the whole virtual machine hangs when IO does not come back!
Date: Sun, 17 Aug 2014 10:12:53 +0200 [thread overview]
Message-ID: <53F06405.4010807@redhat.com> (raw)
In-Reply-To: <33183CC9F5247A488A2544077AF1902086C29CAB@SZXEMA503-MBS.china.huawei.com>
Il 11/08/2014 13:39, Gonglei (Arei) ha scritto:
>> I think the VM hangs there because the VCPU thread holds the global
>> qemu metux lock and waits for IO to come back. However, in my test, the
>> IO doesn't come back (because of the multipath software). Therefore, the
>> VCPU thread never releases the global lock, and other threads can never
>> get the lock. Is there any idea to solve the whole vm hanging problem?
The problem is that qemu_aio_cancel is a synchronous function.
You can work around it with an eh_times_out function in the virtio-scsi
driver, but the real fix would be in QEMU.
Paolo
>> I also did the same test on the VMware platform, the IO hangs but the VM
>> is still working. Thanks!
>>
>
next prev parent reply other threads:[~2014-08-17 8:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-11 10:08 [Qemu-devel] the whole virtual machine hangs when IO does not come back! Bin Wu
2014-08-11 11:39 ` Gonglei (Arei)
2014-08-17 8:12 ` Paolo Bonzini [this message]
-- strict thread matches above, loose matches on Subject: below --
2014-08-11 8:33 Bin Wu
2014-08-11 14:21 ` Stefan Hajnoczi
2014-08-12 0:58 ` Fam Zheng
2014-08-12 1:10 ` Bin Wu
2014-09-08 8:35 ` Stefan Hajnoczi
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