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Re: [Qemu-devel] [RFC PATCH 0/6] virtio-trace: Support virtio-trace
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [RFC PATCH 0/6] virtio-trace: Support virtio-trace |
Date: |
Tue, 24 Jul 2012 11:02:04 +0100 |
On Tue, Jul 24, 2012 at 3:36 AM, Yoshihiro YUNOMAE
<address@hidden> wrote:
> The performance of each method is compared as follows:
> [1] Native
> - only recording trace data to ring-buffer on a guest
> [2] Virtio-trace
> - running a trace agent on a guest
> - a reader on a host opens FIFO using cat command
> [3] IVRing
> - A SystemTap script in a guest records trace data to IVRing.
> -- probe points are same as ftrace.
> [4] Virtio-serial(normal)
> - A reader(using cat) on a guest output trace data to a host using
> standard output via virtio-serial.
The first time I read this I thought you are adding a new virtio-trace
device. But it looks like this series really add splice support to
virtio-console and that yields a big performance improvement when
sending trace_pipe_raw.
Guest ftrace is useful and I like this. Have you thought about
controlling ftrace from the host? Perhaps a command could be added to
the QEMU guest agent which basically invokes trace-cmd/perf.
Are you using text formatted ftrace?
Stefan
- [Qemu-devel] [RFC PATCH 0/6] virtio-trace: Support virtio-trace, Yoshihiro YUNOMAE, 2012/07/23
- [Qemu-devel] [RFC PATCH 1/6] virtio/console: Add splice_write support, Yoshihiro YUNOMAE, 2012/07/23
- [Qemu-devel] [RFC PATCH 2/6] virtio/console: Add a failback for unstealable pipe buffer, Yoshihiro YUNOMAE, 2012/07/23
- [Qemu-devel] [RFC PATCH 3/6] virtio/console: Wait until the port is ready on splice, Yoshihiro YUNOMAE, 2012/07/23
- [Qemu-devel] [RFC PATCH 4/6] ftrace: Allow stealing pages from pipe buffer, Yoshihiro YUNOMAE, 2012/07/23
- [Qemu-devel] [RFC PATCH 5/6] virtio/console: Allocate scatterlist according to the current pipe size, Yoshihiro YUNOMAE, 2012/07/23
- [Qemu-devel] [RFC PATCH 6/6] tools: Add guest trace agent as a user tool, Yoshihiro YUNOMAE, 2012/07/23
- Re: [Qemu-devel] [RFC PATCH 0/6] virtio-trace: Support virtio-trace, Masami Hiramatsu, 2012/07/23
- Re: [Qemu-devel] [RFC PATCH 0/6] virtio-trace: Support virtio-trace,
Stefan Hajnoczi <=
- Re: [Qemu-devel] [RFC PATCH 0/6] virtio-trace: Support virtio-trace, Stefan Hajnoczi, 2012/07/24
Re: [Qemu-devel] [RFC PATCH 0/6] virtio-trace: Support virtio-trace, Blue Swirl, 2012/07/24
Re: [Qemu-devel] [RFC PATCH 0/6] virtio-trace: Support virtio-trace, Amit Shah, 2012/07/26