From: David Miller <davem@davemloft.net>
To: ubraun@linux.vnet.ibm.com
Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org,
schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com,
utz.bacher@de.ibm.com
Subject: Re: [PATCH RESEND net-next 13/15] smc: receive data from RMBE
Date: Tue, 09 Aug 2016 14:32:45 -0700 (PDT) [thread overview]
Message-ID: <20160809.143245.2022037008405834176.davem@davemloft.net> (raw)
In-Reply-To: <1470737580-43012-14-git-send-email-ubraun@linux.vnet.ibm.com>
From: Ursula Braun <ubraun@linux.vnet.ibm.com>
Date: Tue, 9 Aug 2016 12:12:58 +0200
> + xchg(&conn->rx_curs_confirmed.acurs,
> + smc_curs_read(conn->local_tx_ctrl.cons.acurs));
Why in the world do you need to use xchg() in all of these places?
It makes no sense whatsoever, especially since you don't even check
the return value.
If you need the operation to be atomic, then you have to check the
return value and do something to recover if something else beat
you to the xchg() and put something else into the location.
Otherwise, you therefore don't need it be atomic and can avoid
this expensive operation and just store the value normally.
next prev parent reply other threads:[~2016-08-09 21:32 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-09 10:12 [PATCH RESEND net-next 00/15] net/smc: Shared Memory Communications - RDMA Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 01/15] net: introduce keepalive function in struct proto Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 02/15] smc: establish new socket family Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 03/15] smc: establish pnet table management Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 04/15] smc: introduce SMC as an IB-client Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 05/15] smc: CLC handshake (incl. preparation steps) Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 06/15] smc: connection and link group creation Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 07/15] smc: remote memory buffers (RMBs) Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 08/15] smc: work request (WR) base for use by LLC and CDC Ursula Braun
2016-08-09 12:29 ` kbuild test robot
2016-08-09 10:12 ` [PATCH RESEND net-next 09/15] smc: initialize IB transport incl. PD, MR, QP, CQ, event, WR Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 10/15] smc: link layer control (LLC) Ursula Braun
2016-08-09 10:12 ` [PATCH RESEND net-next 11/15] smc: connection data control (CDC) Ursula Braun
2016-08-09 14:02 ` kbuild test robot
2016-08-09 10:12 ` [PATCH RESEND net-next 12/15] smc: send data (through RDMA) Ursula Braun
2016-08-09 14:43 ` kbuild test robot
2016-08-09 10:12 ` [PATCH RESEND net-next 13/15] smc: receive data from RMBE Ursula Braun
2016-08-09 21:32 ` David Miller [this message]
2016-08-10 13:44 ` Ursula Braun
2016-08-10 15:15 ` Fwd: " Ursula Braun
2016-08-10 17:45 ` David Miller
2016-09-02 13:05 ` Ursula Braun
2016-09-02 17:59 ` David Miller
2016-08-09 10:12 ` [PATCH RESEND net-next 14/15] smc: socket closing and linkgroup cleanup Ursula Braun
2016-08-09 12:55 ` [PATCH] smc: fix semicolon.cocci warnings kbuild test robot
2016-08-09 12:55 ` [PATCH RESEND net-next 14/15] smc: socket closing and linkgroup cleanup kbuild test robot
2016-08-09 12:55 ` [PATCH] smc: fix boolreturn.cocci warnings kbuild test robot
2016-08-09 10:13 ` [PATCH RESEND net-next 15/15] smc: proc-fs interface for smc connections Ursula Braun
2016-08-09 21:40 ` David Miller
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=20160809.143245.2022037008405834176.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=heiko.carstens@de.ibm.com \
--cc=linux-s390@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=schwidefsky@de.ibm.com \
--cc=ubraun@linux.vnet.ibm.com \
--cc=utz.bacher@de.ibm.com \
/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;
as well as URLs for NNTP newsgroup(s).