From: Eric Blake <eblake@redhat.com>
To: Max Reitz <mreitz@redhat.com>, qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v2] block/raw-posix: Try both FIEMAP and SEEK_HOLE
Date: Tue, 06 May 2014 15:47:15 -0600 [thread overview]
Message-ID: <53695863.9080009@redhat.com> (raw)
In-Reply-To: <536951A9.1070200@redhat.com>
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On 05/06/2014 03:18 PM, Eric Blake wrote:
> ...if you are on a file system where SEEK_HOLE triggers the kernel
> fallback of "entire file is allocated", but where FIEMAP is wired up for
> that file system, would it make sense to have try_seek_hole return -1 in
> situations where lseek(s->fd, 0, SEEK_HOLE) returns the end of the file?
> Even more, should skip_seek_hole be a tri-state?
On the other hand, such systems are getting vanishingly rare as people
upgrade to newer kernels. Do we care about catering to them, or is it
fair game to just tell people to upgrade if they want performance?
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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next prev parent reply other threads:[~2014-05-06 21:47 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-06 19:00 [Qemu-devel] [PATCH v2] block/raw-posix: Try both FIEMAP and SEEK_HOLE Max Reitz
2014-05-06 21:18 ` Eric Blake
2014-05-06 21:35 ` Max Reitz
2014-05-06 21:47 ` Eric Blake [this message]
2014-05-06 21:48 ` Max Reitz
2014-05-07 5:56 ` Markus Armbruster
2014-05-08 18:35 ` Max Reitz
2014-05-09 8:03 ` Paolo Bonzini
2014-05-11 17:26 ` Christoph Hellwig
2014-05-14 23:13 ` Max Reitz
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