From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:34204) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UanPQ-0004dX-Td for qemu-devel@nongnu.org; Fri, 10 May 2013 09:30:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UanPP-0001D2-0z for qemu-devel@nongnu.org; Fri, 10 May 2013 09:30:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54646) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UanPO-0001Co-NV for qemu-devel@nongnu.org; Fri, 10 May 2013 09:30:50 -0400 Message-ID: <518CF669.30803@redhat.com> Date: Fri, 10 May 2013 15:30:17 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1368188203-3407-1-git-send-email-pbonzini@redhat.com> <874nebdm4r.fsf@codemonkey.ws> <518CF130.2030402@redhat.com> <518CF4C4.6020901@suse.de> In-Reply-To: <518CF4C4.6020901@suse.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH for-1.5 0/9] Disable expensive QOM cast debugging for official releases List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?ISO-8859-1?Q?Andreas_F=E4rber?= Cc: Anthony Liguori , qemu-devel@nongnu.org, Aurelien Jarno , mst@redhat.com Il 10/05/2013 15:23, Andreas F=E4rber ha scritto: > Am 10.05.2013 15:08, schrieb Paolo Bonzini: >> Il 10/05/2013 15:01, Anthony Liguori ha scritto: >>> I'd prefer not to disable but instead focus on improving performance. >> >> For 1.5? This is a regression in 1.5 due to more and more usage of >> foo_env_on_cpu. >=20 > If CPUs were the only reason, we could simply change those inlines and > ENV_GET_CPU() macro to use a C cast. No complicated interface scenarios > requiring a dynamic cast are used for CPUs so far to my knowledge. Almost nothing really requires a dynamic cast in QEMU. Only interface casts do, and there's just a couple of uses of interfaces. And I wrote in the cover letter that what I want is really avoid the need for "fast casts" in the hot paths. Can you guys actually read the commit messages? > Either way, it would be nice to see the call sites of those > most-impacting dynamic casts! So far I held back my APIC RFC since I'm > not sure how to reproducibly profile things. It's interrupts (both sending and returning from them). Paolo