On Wed, Apr 28, 2021 at 8:33 PM Chaitanya Kulkarni <Chaitanya.Kulkarni@xxxxxxx> wrote: > > On 4/27/21 23:14, Gioh Kim wrote: > > The IO performance test with fio after removing the likely and > > unlikely macros in all if-statement shows no performance drop. > > They do not help for the performance of rnbd. > > > > The fio test did random read on 32 rnbd devices and 64 processes. > > Test environment: > > - AMD Opteron(tm) Processor 6386 SE > > - 125G memory > > - kernel version: 5.4.86 > > why 5.4 and not linux-block/for-next ? We have done porting only 5.4 for the server machine yet. > > > - gcc version: gcc (Debian 8.3.0-6) 8.3.0 > > - Infiniband controller: InfiniBand: Mellanox Technologies MT26428 > > [ConnectX VPI PCIe 2.0 5GT/s - IB QDR / 10GigE] (rev b0) > > > > before > > read: IOPS=549k, BW=2146MiB/s > > read: IOPS=544k, BW=2125MiB/s > > read: IOPS=553k, BW=2158MiB/s > > read: IOPS=535k, BW=2089MiB/s > > read: IOPS=543k, BW=2122MiB/s > > read: IOPS=552k, BW=2154MiB/s > > average: IOPS=546k, BW=2132MiB/s > > > > after > > read: IOPS=556k, BW=2172MiB/s > > read: IOPS=561k, BW=2191MiB/s > > read: IOPS=552k, BW=2156MiB/s > > read: IOPS=551k, BW=2154MiB/s > > read: IOPS=562k, BW=2194MiB/s > > ----------- > > average: IOPS=556k, BW=2173MiB/s > > > > The IOPS and bandwidth got better slightly after removing > > likely/unlikely. (IOPS= +1.8% BW= +1.9%) But we cannot make sure > > that removing the likely/unlikely help the performance because it > > depends on various situations. We only make sure that removing the > > likely/unlikely does not drop the performance. > > Did you get a chance to collect perf numbers to see which functions are > getting faster ? I knew somebody would ask for it ;-) No, I didn't because I have been occupied with another task. But I will check it soon in a few weeks. Thank you for the review. > >
