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alistair23-linux/drivers/vhost
Jason Wang 8b949bef91 vhost_net: correctly check tx avail during rx busy polling
We check tx avail through vhost_enable_notify() in the past which is
wrong since it only checks whether or not guest has filled more
available buffer since last avail idx synchronization which was just
done by vhost_vq_avail_empty() before. What we really want is checking
pending buffers in the avail ring. Fix this by calling
vhost_vq_avail_empty() instead.

This issue could be noticed by doing netperf TCP_RR benchmark as
client from guest (but not host). With this fix, TCP_RR from guest to
localhost restores from 1375.91 trans per sec to 55235.28 trans per
sec on my laptop (Intel(R) Core(TM) i7-5600U CPU @ 2.60GHz).

Fixes: 0308813724 ("vhost_net: basic polling support")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-05 14:47:32 -07:00
..
Kconfig tap: tap as an independent module 2017-02-11 20:59:41 -05:00
Kconfig.vringh vhost: split out vringh Kconfig 2016-08-02 16:54:28 +03:00
Makefile VSOCK: Add Makefile and Kconfig 2016-08-02 02:57:30 +03:00
net.c vhost_net: correctly check tx avail during rx busy polling 2017-09-05 14:47:32 -07:00
scsi.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2017-07-13 14:27:32 -07:00
test.c Merge 4.8-rc5 into char-misc-next 2016-09-05 08:04:07 +02:00
test.h vhost test module 2010-12-09 16:00:21 +02:00
vhost.c Revert "vhost: cache used event for better performance" 2017-07-29 14:15:56 -07:00
vhost.h Revert "vhost: cache used event for better performance" 2017-07-29 14:15:56 -07:00
vringh.c vringh: kill off ACCESS_ONCE() 2016-12-16 00:13:36 +02:00
vsock.c mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic 2017-07-12 16:26:03 -07:00