From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NuqwH-0001fN-Cu for qemu-devel@nongnu.org; Thu, 25 Mar 2010 13:33:49 -0400 Received: from [140.186.70.92] (port=41690 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NuqwE-0001bh-C8 for qemu-devel@nongnu.org; Thu, 25 Mar 2010 13:33:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1Nuqw5-0003Ob-Cr for qemu-devel@nongnu.org; Thu, 25 Mar 2010 13:33:39 -0400 Received: from static-71-162-243-5.phlapa.fios.verizon.net ([71.162.243.5]:55814 helo=grelber.thyrsus.com) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1Nuqw5-0003OV-6T for qemu-devel@nongnu.org; Thu, 25 Mar 2010 13:33:37 -0400 From: Rob Landley Subject: Re: [Qemu-devel] Significant performance regression in qemu-system-mips. Date: Thu, 25 Mar 2010 12:33:33 -0500 References: <201003241534.01219.rob@landley.net> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <201003251233.34579.rob@landley.net> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Artyom Tarasenko Cc: qemu-devel@nongnu.org On Thursday 25 March 2010 04:20:26 Artyom Tarasenko wrote: > 2010/3/24 Rob Landley : > > I have a native build under qemu that gets killed if it doesn't produce a > > line of output for 60 seconds (hang detection enforced by the host > > monitoring qemu's stdout with --nographic, not from within qemu). > > > > In the most recent release version, it never came close to triggering on > > mips with a 30 second timeout. In the current -git version (well, as of > > Thursday anyway), it triggers frequently (about 90% of the time) even > > with a 60 second timeout. > > Are other platforms affected as well? Do your automated tests run > against qemu-sparc meanwhile? That was the only platform I hit this particular regression on. It affects mips, mipsel, and mips64. The arm, x86, and x86-64 targets built to the end just fine. Sparc works fine from a performance perspective (the timeout doesn't trigger), it just dies building strace with: In file included from file.c:88:^M /usr/bin/../include/asm/stat.h:56: error: expected specifier-qualifier-list before 'uid16_t'^ Which is either an strace bug or something wrong with the kernel headers, either way I need too track that down and fix it. Powerpc got broken by the 2.6.32->2.6.33 kernel upgrade (the hard drives don't work because something broke in DMA interrupt handling, I'm bisecting it), so I can't comment on its performance at the moment. I'll get back to you on that one. As far as I can tell the sh4 linux-kernel maintainer officially doesn't care about anybody who isn't employed by his company, so I'm not sure I still care about supporting that platform. It's not real hardware, it's a one-company toy: http://permalink.gmane.org/gmane.linux.ports.sh.devel/7233 http://permalink.gmane.org/gmane.linux.ports.sh.devel/7237 There aren't any system emulations for m68k and alpha upstream in qemu yet, although I live in hope... Rob -- Latency is more important than throughput. It's that simple. - Linus Torvalds