Re: [PATCH] target/user: Add daynmic growing data area feature support

[Mike Christie]

On 02/22/2017 02:32 PM, Andy Grover wrote:
> On 02/17/2017 01:24 AM, lixiubo@xxxxxxxxxxxxxxxxxxxx wrote:
>> > From: Xiubo Li <lixiubo@xxxxxxxxxxxxxxxxxxxx>
>> > 
>> > Currently for the TCMU, the ring buffer size is fixed to 64K cmd
>> > area + 1M data area, and this will be bottlenecks for high iops.
> Hi Xiubo, thanks for your work.
> 
> daynmic -> dynamic
> 
> Have you benchmarked this patch and determined what kind of iops
> improvement it allows? Do you see the data area reaching its
> fully-allocated size?
> 

I tested this patch with Venky's tcmu-runner rbd aio patches, with one
10 gig iscsi session, and for pretty basic fio direct io (64 -256K
read/writes with a queue depth of 64 numjobs between 1 and 4) tests read
throughput goes from about 80 to 500 MB/s. Write throughput is pretty
low at around 150 MB/s.

I did not hit the fully allocated size. I did not drive a lot of IO though.