kern/141305: FreeBSD ZFS+sendfile severe performance issues (no
kevin at your.org
Tue Dec 8 23:30:07 UTC 2009
The following reply was made to PR kern/141305; it has been noted by GNATS.
From: Kevin <kevin at your.org>
To: bug-followup at FreeBSD.org
Subject: Re: kern/141305: FreeBSD ZFS+sendfile severe performance issues (no cache)
Date: Tue, 8 Dec 2009 17:07:00 -0600
I can confirm similar results.
If the filesystem is ZFS, calling sendfile(2) over and over again on
the same file produces constant disk read activity correlating exactly
with the speed in which TCP is sending. Switching to writev(2) or
using UFS instead results in expected levels of disk activity.
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