From: Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>
To: Gioh Kim <gi-oh.kim@ionos.com>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>
Cc: "axboe@kernel.dk" <axboe@kernel.dk>,
"hch@infradead.org" <hch@infradead.org>,
"sagi@grimberg.me" <sagi@grimberg.me>,
"bvanassche@acm.org" <bvanassche@acm.org>,
"haris.iqbal@ionos.com" <haris.iqbal@ionos.com>,
"jinpu.wang@ionos.com" <jinpu.wang@ionos.com>
Subject: Re: [PATCH for-next 4/4] block/rnbd: Remove all likely and unlikely
Date: Wed, 28 Apr 2021 18:33:19 +0000 [thread overview]
Message-ID: <BYAPR04MB496504E1348ABFEE30FFC0C186409@BYAPR04MB4965.namprd04.prod.outlook.com> (raw)
In-Reply-To: 20210428061359.206794-5-gi-oh.kim@ionos.com
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 ?
> - 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 ?
next prev parent reply other threads:[~2021-04-28 18:33 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-28 6:13 [PATCH for-next 0/4] Misc update for RNBD Gioh Kim
2021-04-28 6:13 ` [PATCH for-next 1/4] block/rnbd-clt: Change queue_depth type in rnbd_clt_session to size_t Gioh Kim
2021-04-28 18:27 ` Chaitanya Kulkarni
2021-04-28 6:13 ` [PATCH for-next 2/4] block/rnbd: Fix style issues Gioh Kim
2021-04-28 18:27 ` Chaitanya Kulkarni
2021-04-28 6:13 ` [PATCH for-next 3/4] block/rnbd-clt: Check the return value of the function rtrs_clt_query Gioh Kim
2021-04-28 6:13 ` [PATCH for-next 4/4] block/rnbd: Remove all likely and unlikely Gioh Kim
2021-04-28 18:33 ` Chaitanya Kulkarni [this message]
2021-04-29 7:14 ` Gioh Kim
2021-05-04 13:04 ` Gioh Kim
2021-05-05 13:12 ` Gioh Kim
2021-04-28 14:03 ` [PATCH for-next 0/4] Misc update for RNBD Jens Axboe
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