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Date: Thu, 4 Aug 2011 15:40:10 GMT
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To: freebsd-fs@FreeBSD.org
From: Borja Marcos <borjam@sarenet.es>
Cc: 
Subject: Re: kern/157728: [zfs] zfs (v28) incremental receive may leave
	behind temporary clones
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The following reply was made to PR kern/157728; it has been noted by GNATS.

From: Borja Marcos <borjam@sarenet.es>
To: Martin Matuska <mm@FreeBSD.org>
Cc: bug-followup@FreeBSD.org,
 Pawel Jakub Dawidek <pjd@FreeBSD.org>
Subject: Re: kern/157728: [zfs] zfs (v28) incremental receive may leave behind temporary clones
Date: Thu, 4 Aug 2011 17:37:26 +0200

 On Aug 4, 2011, at 4:18 PM, Martin Matuska wrote:
 
 > But I still think we don't have to prefetch data we are not =
 processing.
 >=20
 > I don't think that there will be any ugly interaction in this case.
 > The idea of the prefetch code is to speed up access to the data
 > structure by caching it into memory.
 > So what we don't prefetch (is not cached) will be read the normal way
 > (and not from cache).
 >=20
 > If you follow its history, you can see it well:
 >=20
 > Prefetch for zfs list was introduced in OpenSolaris changeset 8415 and
 > didn't change very much since that point:
 > http://hg.openindiana.org/illumos-gate/rev/d5525cd1cbc2
 >=20
 > If you remove that code, it will still work the way it should, but =
 slower :)
 > I still see no problem in not-prefetching hidden datasets.
 
 Understood :) Thank you very much. As I said, I'm not that familiar with =
 the internals.
 
 I'm going to try the patch and will let you know the outcome. I guess  =
 it will effectively fix it.
 
 
 
 Best regards,
 
 
 
 
 Borja.