Re: [Qemu-devel] [Bug 955379] Re: cmake hangs with qemu-arm-static

[Alexander Graf]

On 01.12.2012, at 12:27, Peter Maydell wrote:

> On 1 December 2012 10:29, Janne Karhunen <address@hidden> wrote:
>>> this blocks forever, because the thing that would wake it up is the
>> signal handler writing to the pipe we're selecting on, but we will never
>> run the signal handler until select exits
>> 
>> Duh, makes sense, have to think about this. Thank you for great analysis
>> :)
>> 
>> Apparently have to dig into qemu's code to understand this better, but
>> first thought was that do you think it would be possible to add some
>> crude hack bit in qemu's signal handler which we could 'almost
>> atomically' check prior to entering system poll/select/read/whatnot ?
>> This bit would tell there are user signals queued and handlers should be
>> executed first.. ?
> 
> Nope, it's still not going to be non-racy that way (and it would still
> be a pretty invasive change so it doesn't really make it easier either
> I think).

Could you please try and see if this patch makes a difference?

http://repo.or.cz/w/qemu/agraf.git/patch/489924aa0115dc6cfcd4e91b0747da4ff8425d1f


Alex