From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: "Wong Hoi Sing, Edison" <hswong3i@gmail.com>,
"Hung Hing Lun, Mike" <hlhung3i@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <garsilva@embeddedor.com>
Subject: Re: [PATCH] tcp_lp: use 64-bit arithmetic instead of 32-bit
Date: Thu, 1 Feb 2018 00:32:36 +0000 [thread overview]
Message-ID: <20180201003236.06143fd0@alans-desktop> (raw)
In-Reply-To: <20180201002407.GA1608@embeddedgus>
On Wed, 31 Jan 2018 18:24:07 -0600
"Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
> Cast to s64 some variables and a macro in order to give the
> compiler complete information about the proper arithmetic to
> use. Notice that these elements are used in contexts that
> expect expressions of type s64 (64 bits, signed).
>
> Currently such expression are being evaluated using 32-bit
> arithmetic.
The question you need to ask is 'can it overflow 32bit maths', otherwise
you are potentially making the system do extra work for no reason.
Alan
next prev parent reply other threads:[~2018-02-01 0:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-01 0:24 [PATCH] tcp_lp: use 64-bit arithmetic instead of 32-bit Gustavo A. R. Silva
2018-02-01 0:32 ` Alan Cox [this message]
2018-02-01 1:07 ` Gustavo A. R. Silva
2018-02-01 1:51 ` Andrew Lunn
2018-02-02 2:32 ` Gustavo A. R. Silva
2018-02-01 10:14 ` David Laight
2018-02-02 2:33 ` Gustavo A. R. Silva
2018-02-01 14:45 ` David Miller
2018-02-02 2:38 ` Gustavo A. R. Silva
2018-02-02 9:32 ` kbuild test robot
2018-02-02 10:44 ` kbuild test robot
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