Christoph Hellwig hch at infradead.org writes:
Ok. cache=writeback performance is something I haven't bothered looking
at at all. For cache=none any streaming write or random workload with
large enough record sizes got basically the same performance as native
using kernel aio, and same for
with vhost-blk:
# time dd if=/dev/vda of=/dev/null bs=128k iflag=direct
64+0 records in
64+0 records out
8388608 bytes (84 GB) copied, 126.135 seconds, 665 MB/s
# time dd of=/dev/vda if=/dev/zero bs=2M oflag=direct
Can you please check both read write
Another issue I noticed while looking at the results is large
fluctuations in ide results. The standard deviation of
the ide results is very large. A large portion of the results are
around 30GB/sec and around 80GB/sec.
Is there any meaningful explanation for this large variation? Is there
Christoph Hellwig hch at lst.de writes:
File size set to 131072 KB
Record Size 4 KB
O_DIRECT feature enabled
Command line used: iozone -s 128m -r 4k -I -f /dev/sdb
Apologies for multiple posts, might have a problem with my mail.
Can you please elaborate more on the
Christoph Hellwig hch at lst.de writes:
File size set to 131072 KB
Record Size 4 KB
O_DIRECT feature enabled
Command line used: iozone -s 128m -r 4k -I -f /dev/sdb
is /dev/sdb a local disk, network drive attached via FC/IB, something else?
What is the command line
Christoph Hellwig hch at lst.de writes:
Michael suggested to me a while ago to try MSI with virtio-blk and I
played with this small patch:
which gave about 5% speedups on 4k sized reads and writes, see the full
iozone output I attached.
File size set to 131072 KB
Record Size
Eran Rom eranr at il.ibm.com writes:
When Host and Guest ran 2.6.27 with kvm-87 (both qemu-kvm and kvm-kmod), the
problem persisted. Thus, I am looking for a kernel fix that is not
part of KVM,
any lead? Am confined to use 2.6.27
Marcelo Tosatti mtosa...@redhat.com wrote on 16/07/2009 01
Glauber Costa glommer at redhat.com writes:
This was happening with kvmclock back then when it did not handle
cpu frequency changes. What are the details of the host hw?
Glauber, any clues?
maybe it is exactly that. 2.6.27 is a little bit old, and probably does not
have the fixes.
Glauber Costa glommer at redhat.com writes:
This was happening with kvmclock back then when it did not handle
cpu frequency changes. What are the details of the host hw?
Glauber, any clues?
maybe it is exactly that. 2.6.27 is a little bit old, and probably does not
have the fixes.
Eran Rom eranr at il.ibm.com writes:
Eran Rom eranr at il.ibm.com writes:
Still getting a misbehaving clock:
guest uses kvmclock with kernel 2.6.27
host kernel is 2.6.27 with kvm-qemu-87 kvm-kmod-87
getting:
...
now = 2128043797
now = 2138048010
now
Eran Rom eranr at il.ibm.com writes:
Avi Kivity avi at redhat.com writes:
2.6.27 has kvmclock.
Thanks a lot!
Will try the kvmclock
Eran
Still getting a misbehaving clock:
guest uses kvmclock with kernel 2.6.27
host kernel is 2.6.27 with kvm-qemu-87 kvm-kmod-87
doing:
now
Avi Kivity avi at redhat.com writes:
2.6.27 has kvmclock.
Thanks a lot!
Will try the kvmclock
Eran
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Dor Laor dlaor at redhat.com writes:
On 06/25/2009 04:25 PM, Eran Rom wrote:
Behavior:
Running a code doing:
t1 = gettimeofday
t2 = gettimeofday
while t2-t1 5 minutes {
sleep(1)
t2 = gettimeofday
}
Ran it 10 times, each time in a 'newly launched' VM,
halting
Hi All,
Am a newbie (to kvm, linux kernel, git, etc.) so apologize in advance for
missing/inaccurate info.
I am experiencing inconsistent behavior of guest gettimeofday, described below.
I have seen prior reference to the problem, however, it was not clear whether
the issue was solved or not and
The Host--Guest calls in virtio_blk (using the generic virtio kick/notify)
are as follows:
Guest-Host
---
do_virtlkb_request calls kick in the guest side causing handle_output to be
called on the host side.
Host-Guest
---
virtio_blk_rw_complete calls notify in the host side
15 matches
Mail list logo
