[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] Re: segmentation fault in qemu-kvm-0.14.0

From: Jan Kiszka
Subject: Re: [Qemu-devel] Re: segmentation fault in qemu-kvm-0.14.0
Date: Wed, 09 Mar 2011 11:12:53 +0100
User-agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv: Gecko/20080226 SUSE/ Thunderbird/ Mnenhy/

On 2011-03-09 11:06, Corentin Chary wrote:
>> Probably the best way is to make vnc stop fiddling with
>> qemu_set_fd_handler2, specifically in threaded mode.
>> Why does it need to set/reset the write handler all the time?
> I didn't write the original code, but it's probably to avoid calling a
> write handler when there is no data to write. That would make select()
> busy loop when there are actually no data to write.
> There is also the vnc_disconnect_start() case when the socket seems to
> be broken and we remove all handlers.
>> The other question is: Who's responsible for writing to the client
>> socket in threaded mode? Only the vnc thread(s), or also other qemu
>> threads? In the former case, just avoid setting a write handler at all.
> Cheap stuff is done by the main thread (cursor, etc...). The thread
> only do framebuffer updates.

And both are synchronized with a vnc-private lock only?

The problem with this model is the non-threaded qemu execution model.
Even if we acquire the global mutex to protect handler updates against
the main select loop, this won't help here. So vnc-threading likely
needs to be made dependent on --enable-io-thread.


Attachment: signature.asc
Description: OpenPGP digital signature

reply via email to

[Prev in Thread] Current Thread [Next in Thread]