On 2011-06-16 17:24, Alexandre Raymond wrote: > Hi Jan, > > On Thu, Jun 16, 2011 at 5:31 AM, Jan Kiszka <jan.kis...@siemens.com> wrote: >> Ingo Molnar pointed out that sending the timer signal to the whole >> process, just blocking it everywhere, is suboptimal with an increasing >> number of threads. QEMU is using this pattern so far. > > I am not familiar with this code, but don't you already need to block > SIGALRM properly in all threads for OSes != Linux ? If so, isn't this > patch redundant?
Yes, we still need to block for the sake of non-Linux UNIX or pre-signalfd Linux. That blocking becomes in fact redundant in the signalfd case, but that's both harmless and not worth optimizing. The key is that per-thread signals do not care about other threads having them blocked or not, they only deal with the target thread. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
