From: "Benoît Canet" <benoit.canet@irqsave.net>
To: Kevin Wolf <kwolf@redhat.com>
Cc: benoit.canet@irqsave.net, famz@redhat.com, jcody@redhat.com,
qemu-devel@nongnu.org, mreitz@redhat.com,
Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [RFC] qcow2 journalling draft
Date: Thu, 5 Sep 2013 14:08:00 +0200 [thread overview]
Message-ID: <20130905120759.GA5095@irqsave.net> (raw)
In-Reply-To: <20130905115028.GF2826@dhcp-200-207.str.redhat.com>
> Then you get very quickly alternating sequences of "L2 depends on
> refcount update" (for allocation) and "refcount update depends on L2
> update" (for freeing), which means that Qcow2Cache starts flushing all
> the time without accumulating many requests. These are cases that would
> benefit as well from the atomicity of journal transactions.
True, Deduplication can hit this case on delete if I remember correctly
and it slow down everything.
Best regards
Benoît
next prev parent reply other threads:[~2013-09-05 12:06 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-03 13:45 [Qemu-devel] [RFC] qcow2 journalling draft Kevin Wolf
2013-09-03 14:43 ` Benoît Canet
2013-09-04 8:03 ` Stefan Hajnoczi
2013-09-04 9:37 ` Benoît Canet
2013-09-04 9:39 ` Kevin Wolf
2013-09-04 9:55 ` Benoît Canet
2013-09-05 9:24 ` Stefan Hajnoczi
2013-09-05 15:26 ` Benoît Canet
2013-09-06 7:27 ` Kevin Wolf
2013-09-15 18:23 ` Benoît Canet
2013-09-05 9:21 ` Stefan Hajnoczi
2013-09-05 11:18 ` Kevin Wolf
2013-09-05 14:55 ` Stefan Hajnoczi
2013-09-05 15:20 ` Kevin Wolf
2013-09-05 15:56 ` Eric Blake
2013-09-06 9:20 ` Fam Zheng
2013-09-06 9:57 ` Kevin Wolf
2013-09-06 10:02 ` Fam Zheng
2013-09-04 8:32 ` Max Reitz
2013-09-04 10:12 ` Kevin Wolf
2013-09-05 9:35 ` Stefan Hajnoczi
2013-09-05 11:50 ` Kevin Wolf
2013-09-05 12:08 ` Benoît Canet [this message]
2013-09-06 9:59 ` Fam Zheng
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