From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MKzEN-0002Nl-Bt for qemu-devel@nongnu.org; Sun, 28 Jun 2009 14:35:59 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MKzEI-0002NZ-TH for qemu-devel@nongnu.org; Sun, 28 Jun 2009 14:35:58 -0400 Received: from [199.232.76.173] (port=50492 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MKzEI-0002NW-Np for qemu-devel@nongnu.org; Sun, 28 Jun 2009 14:35:54 -0400 Received: from mx2.redhat.com ([66.187.237.31]:46308) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MKzEI-0005pL-FJ for qemu-devel@nongnu.org; Sun, 28 Jun 2009 14:35:54 -0400 Message-ID: <4A47B810.1020500@redhat.com> Date: Sun, 28 Jun 2009 21:36:00 +0300 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [PATCH 08/11] QMP: Port balloon command References: <20090623135958.660903e1@doriath> <4A412135.2060804@us.ibm.com> <4A435F09.7050702@redhat.com> <20090625161143.01b56eea@doriath> <4A4492FD.4040704@redhat.com> <20090626094224.GE28206@redhat.com> <20090627125833.22d3cc9f@doriath> <4A4791D9.2050400@redhat.com> <5b31733c0906281023n637cd3eax60d14bbe618f63ec@mail.gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: Anthony Liguori , ehabkost@redhat.com, jan.kiszka@siemens.com, dlaor@redhat.com, qemu-devel@nongnu.org, Luiz Capitulino , Filip Navara On 06/28/2009 08:51 PM, Blue Swirl wrote: > On 6/28/09, Filip Navara wrote: > >> On Sun, Jun 28, 2009 at 5:52 PM, Avi Kivity wrote: >> > It really isn't very complicated, and >> > the thread only got so long because the topic is relatively simple. Post an >> > RFC and a mile-long patchset about changing TCG to SSA form, and see how you >> > get no replies. >> >> >> I wouldn't even dare to push the SSA patch... Mile-long doesn't >> describe it precisely enough. Imagine it was applied to all the >> targets. >> > > Is there a speed benefit from using the SSA form? > I'm no compiler expert. My understanding is that SSA enables optimizations, so translation speed would decrease, but generated code speed would increase. Other jits increase optimization effort on long running loops, so if a code is run heavily it receives additional attention from the optimizer. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.