virtio_scsi can really use this, to avoid the current hack of copying
the whole sg array. Some other things get slightly neater, too.
This causes a slowdown in virtqueue_add_buf(), which is implemented as
a wrapper. This is addressed in the next patches.
for i in `seq 50`; do /usr/bin/time -f 'Wall time:%e' ./vringh_test --indirect --eventidx --parallel --fast-vringh; done 2>&1 | stats --trim-outliers:
Before:
Using CPUS 0 and 3
Guest: notified 0, pinged 39009-39063(39062)
Host: notified 39009-39063(39062), pinged 0
Wall time:1.700000-1.950000(1.723542)
After:
Using CPUS 0 and 3
Guest: notified 0, pinged 39062-39063(39063)
Host: notified 39062-39063(39063), pinged 0
Wall time:1.760000-2.220000(1.789167)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Reviewed-by: Asias He <asias@redhat.com>
This is mainly to test the drivers/vhost/vringh.c code, but it also
uses the drivers/virtio/virtio_ring.c code for the guest side.
Usage for testing the basic implementation:
./vringh_test
# Test with indirect descriptors
./vringh_test --indirect
# Test with indirect descriptors and event indexex
./vringh_test --indirect --eventidx
You can run a parallel stress test by adding --parallel to any of the
above options.
eg ./vringh_test --parallel:
Using CPUS 0 and 3
Guest: notified 10107974, pinged 107970
Host: notified 108158, pinged 3172148
./vringh_test --indirect --eventidx --parallel:
Using CPUS 0 and 3
Guest: notified 156357, pinged 156251
Host: notified 156251, pinged 78179
Average of 50 times doing ./vringh_test --indirect --eventidx --parallel:
2.840000-3.040000(2.927292)user
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This makes them a bit more like the kernel headers, so we can include more
real kernel headers in our tests.
In addition this means that we don't break tools/virtio with the next
patch.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove wrapper functions. This makes the allocation type explicit in
all callers; I used GPF_KERNEL where it seemed obvious, left it at
GFP_ATOMIC otherwise.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
We were cheating with our barriers; using the smp ones rather than the
real device ones. That was fine, until rpmsg came along, which is
used to talk to a real device (a non-SMP CPU).
Unfortunately, just putting back the real barriers (reverting
d57ed95d) causes a performance regression on virtio-pci. In
particular, Amos reports netbench's TCP_RR over virtio_net CPU
utilization increased up to 35% while throughput went down by up to
14%.
By comparison, this branch is in the noise.
Reference: https://lkml.org/lkml/2011/12/11/22
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is the userspace part of the tool: it includes a bunch of stubs for
linux APIs, somewhat simular to linuxsched. This makes it possible to
recompile the ring code in userspace.
A small test example is implemented combining this with vhost_test
module.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Rusty Russell