From: Bart Van Assche <Bart.VanAssche@wdc.com>
To: "jgg@ziepe.ca" <jgg@ziepe.ca>, "arnd@arndb.de" <arnd@arndb.de>,
"dledford@redhat.com" <dledford@redhat.com>
Cc: Bart Van Assche <Bart.VanAssche@wdc.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"leonro@mellanox.com" <leonro@mellanox.com>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
"sagi@grimberg.me" <sagi@grimberg.me>
Subject: Re: [PATCH] RDMA/core: reduce IB_POLL_BATCH constant
Date: Tue, 20 Feb 2018 21:14:29 +0000 [thread overview]
Message-ID: <1519161268.3737.12.camel@wdc.com> (raw)
In-Reply-To: <20180220205924.2035765-1-arnd@arndb.de>
On Tue, 2018-02-20 at 21:59 +0100, Arnd Bergmann wrote:
> /* # of WCs to poll for with a single call to ib_poll_cq */
> -#define IB_POLL_BATCH 16
> +#define IB_POLL_BATCH 8
The purpose of batch polling is to minimize contention on the cq spinlock.
Reducing the IB_POLL_BATCH constant may affect performance negatively. Has
the performance impact of this change been verified for all affected drivers
(ib_srp, ib_srpt, ib_iser, ib_isert, NVMeOF, NVMeOF target, SMB Direct, NFS
over RDMA, ...)?
Bart.
next prev parent reply other threads:[~2018-02-20 21:14 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-20 20:59 Arnd Bergmann
2018-02-20 21:14 ` Parav Pandit
2018-02-20 21:54 ` Arnd Bergmann
2018-02-20 21:14 ` Bart Van Assche [this message]
2018-02-20 21:47 ` Chuck Lever
2018-02-21 9:47 ` Max Gurtovoy
2018-02-21 13:44 ` Sagi Grimberg
2018-02-21 14:45 ` Max Gurtovoy
2018-02-22 15:39 ` Sagi Grimberg
2018-02-27 22:09 ` Jason Gunthorpe
2018-02-27 22:15 ` Max Gurtovoy
2018-02-28 0:21 ` Bart Van Assche
2018-02-28 9:50 ` Max Gurtovoy
2018-02-28 18:55 ` Doug Ledford
2018-03-01 9:36 ` Max Gurtovoy
2018-02-21 15:10 ` Chuck Lever
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1519161268.3737.12.camel@wdc.com \
--to=bart.vanassche@wdc.com \
--cc=arnd@arndb.de \
--cc=dledford@redhat.com \
--cc=jgg@ziepe.ca \
--cc=leonro@mellanox.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rdma@vger.kernel.org \
--cc=sagi@grimberg.me \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®