From owner-freebsd-fs@FreeBSD.ORG  Thu Apr 22 22:04:54 2010
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Date: Fri, 23 Apr 2010 01:04:50 +0300
From: Andriy Gapon <avg@icyb.net.ua>
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Subject: vdev_geom_io: parallelize ?
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Just thinking out loud.

Currently ZFS vdev_geom_io does something like:
for (...) {
	...
	g_io_request(...);
	biowait(...);
	...
}
I/O is done in MAXPHYS chunks.

If that was changed to first issuing all the requests and only after that
waiting on them, could there be any performance benefit?
Or cases of vdev_geom_io with size > MAXPHYS are too rare?
Or something else?

Thanks!
-- 
Andriy Gapon