From: Stefan Hajnoczi <stefanha@redhat.com>
To: Max Reitz <mreitz@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH v5 0/8] Add metadata overlap checks
Date: Fri, 20 Sep 2013 12:32:02 +0200 [thread overview]
Message-ID: <20130920103202.GA14159@stefanha-thinkpad.redhat.com> (raw)
In-Reply-To: <523B134C.8060902@redhat.com>
On Thu, Sep 19, 2013 at 05:07:56PM +0200, Max Reitz wrote:
> As far as I understand, the I/O speed (the duration of an I/O
> operation) should be pretty much the same for all scenarios,
> however, the latency is the value in question (since the overlap
> checks should affect the latency only).
The other value to look at is the host CPU consumption per I/O. In
other words, the CPU overhead added by performing the extra checks:
efficiency = avg throughput / avg cpu utilization
Once CPU consumption reaches 100% the workload is CPU-bound and we have
a bottleneck.
Hopefully the efficiency doesn't change noticably either, then we know
there is no big impact from the extra checks.
Stefan
next prev parent reply other threads:[~2013-09-20 10:32 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-02 7:25 [Qemu-devel] [PATCH v5 0/8] Add metadata overlap checks Max Reitz
2013-09-02 7:25 ` [Qemu-devel] [PATCH v5 1/8] qcow2: Add corrupt bit Max Reitz
2013-09-02 7:25 ` [Qemu-devel] [PATCH v5 2/8] qcow2: Metadata overlap checks Max Reitz
2013-09-02 7:25 ` [Qemu-devel] [PATCH v5 3/8] qcow2: Employ metadata " Max Reitz
2013-09-02 7:25 ` [Qemu-devel] [PATCH v5 4/8] qcow2-refcount: Move OFLAG_COPIED checks Max Reitz
2013-09-02 7:25 ` [Qemu-devel] [PATCH v5 5/8] qcow2-refcount: Repair OFLAG_COPIED errors Max Reitz
2013-09-02 7:25 ` [Qemu-devel] [PATCH v5 6/8] qcow2-refcount: Repair shared refcount blocks Max Reitz
2013-09-02 7:25 ` [Qemu-devel] [PATCH v5 7/8] qcow2_check: Mark image consistent Max Reitz
2013-09-02 7:25 ` [Qemu-devel] [PATCH v5 8/8] qemu-iotests: Overlapping cluster allocations Max Reitz
2013-09-12 14:57 ` [Qemu-devel] [PATCH v5 0/8] Add metadata overlap checks Eric Blake
2013-09-12 15:24 ` Max Reitz
2013-09-13 9:57 ` Kevin Wolf
2013-09-13 10:23 ` Max Reitz
2013-09-13 12:29 ` Eric Blake
2013-09-13 12:37 ` Max Reitz
2013-09-13 14:29 ` Max Reitz
2013-09-13 14:34 ` Eric Blake
2013-09-19 15:07 ` Max Reitz
2013-09-19 17:26 ` Eric Blake
2013-09-20 8:23 ` Max Reitz
2013-09-20 10:32 ` Stefan Hajnoczi [this message]
2013-10-26 13:03 ` Max Reitz
2013-10-26 13:05 ` Max Reitz
2013-11-05 8:51 ` Stefan Hajnoczi
2013-11-14 18:37 ` Max Reitz
2013-11-15 8:13 ` Stefan Hajnoczi
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