<div dir="ltr">Hi,<div><br></div><div style>Setting IOPRIO doesn't seem to properly distribute I/O for my VEs. I checked the Cgroup blkio and confirmed the blkio.weight is set in scale with the IOPRIO of each VE conf. </div>
<div style><br></div><div style>I tested ex. setting blkio.throttle.write_bps_device and confirmed Cgroup blkio is properly working (setting it to 1024000 does limit the VE to about 1MB/sec). I also checked the processes are properly listed in the Cgroup tasks. However, blkio.weight really doesn't seems to be doing anyting.</div>
<div style><br></div><div style>I'm using the latest stable 2.6.32-042stab068.8.</div><div style><br></div><div style>To test the I/O performance from inside my VE, I run the following in two separate VE, one with an IOPRIO of 1 (blkio.weight of 365) and the other with an IOPRIO of 7 (blkio.weight of 640) :</div>
<div style><br></div><div style>while [ 1 ]; do dd if=/dev/zero of=test bs=1M count=100 oflag=direct; done<br></div><div style><br></div><div style>Both give about the same results.</div><div style><br>The same seems to apply with plain ionice. I get very similar I/O performances independently of the Best-Effort priority I set. However setting one process in the Idle class and the other in Best-Effort does make a difference.</div>
<div style><br></div><div style>I double checked and I am using the CFQ scheduler. Also my VE private directory are on top of an LVM volume, not sure if that could have an impact.</div><div style><br></div><div style>Thanks</div>
<div style><br></div><div style>Simon</div></div>