From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:50929) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4bqt-00056r-19 for qemu-devel@nongnu.org; Thu, 23 Aug 2012 14:09:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T4bqm-0007E7-6L for qemu-devel@nongnu.org; Thu, 23 Aug 2012 14:09:54 -0400 Received: from thoth.sbs.de ([192.35.17.2]:26710) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4bql-0007DO-Sc for qemu-devel@nongnu.org; Thu, 23 Aug 2012 14:09:48 -0400 Message-ID: <503671E8.1090205@siemens.com> Date: Thu, 23 Aug 2012 20:09:44 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <503612B9.1070601@siemens.com> <5036168B.1000900@redhat.com> <50361DB9.20709@siemens.com> <503620F7.3050507@redhat.com> <503629A8.4070501@siemens.com> <50362C09.60508@redhat.com> In-Reply-To: <50362C09.60508@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC][PATCH] qemu-timer: Run timers in alarm timer handler List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Stefan Weil , qemu-devel On 2012-08-23 15:11, Paolo Bonzini wrote: >>> So, in order to remove the qemu_notify_event completely, what about not >>> using signals anymore for timers? You could just tweak the select >>> timeout and drop all the -clock madness. Zero syscalls, practically no >>> overhead. If this is not precise enough, use timerfd on Linux only >> >> Need to think about it. At least, real-time tasks will get proper >> precision on Linux. Not sure if it will be sufficient on other hosts. > > Do we care (I put non-Linux POSIX just a little above Windows but not much)? Well, at least we should not regress. For Windows I just found out that we support millisecond resolution in os_host_main_loop_wait at best due to g_poll. That would be fine, but what is g_poll really using? Likely not mm-timers... Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux