git: VN - Remove use of IO_DIRECT, Improve lock performance for reads
dillon at crater.dragonflybsd.org
Tue Mar 2 23:19:11 PST 2010
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date: Tue Mar 2 23:15:27 2010 -0800
VN - Remove use of IO_DIRECT, Improve lock performance for reads
* Remove the use of IO_DIRECT. This just doesn't work very well,
particularly when the device backing the VN has a different logical
block size than the device using VN.
This will result in heavier use of the buffer cache and more
(temporarily) duplicated data, but also has much better performance.
* Use LK_SHARED for VOP_READ()s instead of LK_EXCLUSIVE, which allows
concurrent reads to be issued.
Reported-by: Vincent Stemen <vince.dragonfly at hightek.org>
Summary of changes:
sys/dev/disk/vn/vn.c | 21 ++++++++++++++++-----
1 files changed, 16 insertions(+), 5 deletions(-)
DragonFly BSD source repository
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