On 01.12.2012, at 12:27, Peter Maydell wrote: > On 1 December 2012 10:29, Janne Karhunen <955...@bugs.launchpad.net> 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
