From: "Pavel Dovgaluk" <Pavel.Dovgaluk@ispras.ru>
To: 'Paolo Bonzini' <pbonzini@redhat.com>, qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, peter.crosthwaite@xilinx.com,
alex.bennee@linaro.org, mark.burton@greensocs.com,
real@ispras.ru, batuzovk@ispras.ru,
maria.klimushenkova@ispras.ru, afaerber@suse.de,
fred.konrad@greensocs.com
Subject: Re: [Qemu-devel] [RFC PATCH v10 18/24] replay: replay aio requests
Date: Mon, 16 Mar 2015 13:40:36 +0300 [thread overview]
Message-ID: <000d01d05fd5$a4240080$ec6c0180$@Dovgaluk@ispras.ru> (raw)
In-Reply-To: <550317FA.6090301@redhat.com>
> From: Paolo Bonzini [mailto:pbonzini@redhat.com]
> On 27/02/2015 14:11, Pavel Dovgalyuk wrote:
> > This patch adds identifier to aio requests. ID is used for creating bottom
> > halves and identifying them while replaying.
> > The patch also introduces several functions that make possible replaying
> > of the aio requests.
>
> Out of curiosity, why did you use this approach instead of using a
> RR-specific block device backend (as you did for network, I think)? The
> backend could just store the data that is read in the RR file (or in a
> separate file that can be easily mmap-ed), and use a timer to trigger it
> at the right QEMU_CLOCK_VIRTUAL tick.
>
> I'm sure you considered something like this. Did you still get
> non-determinism?
We considered this approach. But it requires too much data to be written.
E.g. when loading an OS guest VM reads gigabytes of data. Writing all
this data to file incurs significant slowdown.
Pavel Dovgalyuk
next prev parent reply other threads:[~2015-03-16 10:40 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-27 13:09 [Qemu-devel] [RFC PATCH v10 00/24] Deterministic replay core Pavel Dovgalyuk
2015-02-27 13:09 ` [Qemu-devel] [RFC PATCH v10 01/24] i386: partial revert of interrupt poll fix Pavel Dovgalyuk
2015-02-27 13:09 ` [Qemu-devel] [RFC PATCH v10 02/24] replay: global variables and function stubs Pavel Dovgalyuk
2015-03-13 19:07 ` Eric Blake
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 03/24] sysemu: system functions for replay Pavel Dovgalyuk
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 04/24] replay: internal functions for replay log Pavel Dovgalyuk
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 05/24] replay: introduce mutex to protect the " Pavel Dovgalyuk
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 06/24] replay: introduce icount event Pavel Dovgalyuk
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 07/24] cpu-exec: allow temporary disabling icount Pavel Dovgalyuk
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 08/24] cpu: replay instructions sequence Pavel Dovgalyuk
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 09/24] i386: interrupt poll processing Pavel Dovgalyuk
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 10/24] replay: interrupts and exceptions Pavel Dovgalyuk
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 11/24] replay: asynchronous events infrastructure Pavel Dovgalyuk
2015-02-27 13:10 ` [Qemu-devel] [RFC PATCH v10 12/24] replay: recording and replaying clock ticks Pavel Dovgalyuk
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 13/24] timer: replace time() with QEMU_CLOCK_HOST Pavel Dovgalyuk
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 14/24] replay: shutdown event Pavel Dovgalyuk
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 15/24] replay: checkpoints Pavel Dovgalyuk
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 16/24] aio: replace stack of bottom halves with queue Pavel Dovgalyuk
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 17/24] replay: bottom halves Pavel Dovgalyuk
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 18/24] replay: replay aio requests Pavel Dovgalyuk
2015-03-13 17:01 ` Paolo Bonzini
2015-03-16 10:40 ` Pavel Dovgaluk [this message]
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 19/24] replay: thread pool Pavel Dovgalyuk
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 20/24] typedef: add typedef for QemuOpts Pavel Dovgalyuk
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 21/24] replay: initialization and deinitialization Pavel Dovgalyuk
2015-02-27 13:11 ` [Qemu-devel] [RFC PATCH v10 22/24] replay: replay blockers for devices Pavel Dovgalyuk
2015-02-27 13:12 ` [Qemu-devel] [RFC PATCH v10 23/24] replay: command line options Pavel Dovgalyuk
2015-02-27 13:12 ` [Qemu-devel] [RFC PATCH v10 24/24] replay: recording of the user input Pavel Dovgalyuk
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