[PATCH 0/3 RFC] fsperf: enhancements supporting read policy benchmark

[Anand Jain <anand.jain@oracle.com>]

I am sending this early to seek feedback on the best way to benchmark 
more than one read policy.

Patch 1,2 adds helpers to support a new setup.
Patch 3 adds a generic readonly dio fio benchmark script.

How to run:
Manage the read policy in the config file as required.

For example:

$ cat local.cfg
    [main]
    directory=/mnt/test

    [btrfs-pid]
    device=/dev/vg/scratch0
    mkfs=mkfs.btrfs -f -draid1 -mraid1 /dev/vg/scratch1
    mount=mount -o noatime
    readpolicy=pid
    
    [btrfs-new-policy]
    device=/dev/vg/scratch0
    mkfs=mkfs.btrfs -f -draid1 -mraid1 /dev/vg/scratch1
    mount=mount -o noatime
    readpolicy=new-policy

$ ./fsperf -c btrfs-pid diorandread
snip

$ ./fsperf -c btrfs-new-policy -t -C btrfs-pid diorandread
::
btrfs-new-policy test results
diorandread results
     metric         baseline   current    stdev         diff      
==================================================================
read_lat_ns_max     1.36e+08   1.09e+08       0   -20.02%
write_iops                 0          0       0     0.00%
read_clat_ns_p50     2277376    2244608       0    -1.44%
write_io_kbytes            0          0       0     0.00%
read_clat_ns_p99    12910592   11862016       0    -8.12%
write_bw_bytes             0          0       0     0.00%
read_iops            5680.85    5848.49       0     2.95%
write_clat_ns_p50          0          0       0     0.00%
read_io_bytes       1.40e+09   1.44e+09       0     2.95%
read_io_kbytes       1363496    1403708       0     2.95%
write_clat_ns_p99          0          0       0     0.00%
elapsed                   61         61       0     0.00%
read_bw_bytes       23268780   23955418       0     2.95%
sys_cpu                12.42      13.41       0     7.93%
write_lat_ns_min           0          0       0     0.00%
read_lat_ns_min       164944     189882       0    15.12%
write_lat_ns_max           0          0       0     0.00%

Anand Jain (3):
  fsperf: add a few helper functions
  fsperf: get the running section in the setup
  fsperf: add a new test case diorandread

 local-cfg-example        |  6 ++++++
 src/fsperf.py            |  2 +-
 src/utils.py             | 45 ++++++++++++++++++++++++++++++++++++++++
 tests/dio-randread.py    | 22 ++++++++++++++++++++
 tests/randwrite-2xram.py |  2 +-
 tests/untar-firefox.py   |  2 +-
 6 files changed, 76 insertions(+), 3 deletions(-)
 create mode 100644 tests/dio-randread.py

-- 
2.33.1