From: Stefan Hajnoczi <stefanha@gmail.com>
To: 陳韋任 <chenwj@iis.sinica.edu.tw>
Cc: Alexander Graf <agraf@suse.de>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Improve QEMU performance with LLVM codegen and other techniques
Date: Thu, 1 Dec 2011 07:46:57 +0000 [thread overview]
Message-ID: <20111201074657.GA29861@stefanha-thinkpad.localdomain> (raw)
In-Reply-To: <20111201035024.GA88545@cs.nctu.edu.tw>
On Thu, Dec 01, 2011 at 11:50:24AM +0800, 陳韋任 wrote:
> > I don't see any better approach to debugging this than the one you're already taking. Try to run as many workloads as you can and see if they break :). Oh and always make the optimization optional, so that you can narrow it down to it and know you didn't hit a generic QEMU bug.
>
> You mean make the trace optimization optional? We have tested our framework in
> LLVM-only mode. which means we replace TCG with LLVM entirely. It's _very_ slow
> but works.
It would be interesting to use an optimized interpreter instead of TCG,
then go to LLVM for hot traces. This is more HotSpot-like with the idea
being that the interpreter runs through initialization and rarely
executed code without a translation overhead. For the hot paths LLVM
kicks in and high-quality translated code is executed.
Stefan
next prev parent reply other threads:[~2011-12-01 9:13 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-29 7:03 [Qemu-devel] Improve QEMU performance with LLVM codegen and other techniques 陳韋任
2011-11-30 12:37 ` Alexander Graf
2011-12-01 3:50 ` 陳韋任
2011-12-01 7:46 ` Stefan Hajnoczi [this message]
2011-12-01 9:16 ` Alex Bradbury
2011-12-01 9:30 ` 陳韋任
2011-12-01 10:23 ` Alexander Graf
2011-12-04 6:14 ` 陳韋任
2011-12-04 11:29 ` Alexander Graf
2011-12-05 6:05 ` 陳韋任
2011-12-01 10:59 ` Peter Maydell
2011-12-06 7:39 ` 陳韋任
2011-12-19 17:44 ` Alexander Graf
2011-11-30 12:51 ` Peter Maydell
2011-12-01 9:03 ` 陳韋任
2011-12-01 9:13 ` 陳韋任
2011-12-01 9:15 ` Max Filippov
2011-12-01 9:25 ` 陳韋任
2011-12-01 9:41 ` Max Filippov
2011-12-06 6:37 ` 陳韋任
2011-12-01 10:12 ` Peter Maydell
2011-12-01 10:40 ` 陳韋任
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