From: Joe Perches <joe@perches.com>
To: Michael Davidson <md@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>,
David Miller <davem@davemloft.net>,
Matthew Wilcox <mawilcox@microsoft.com>,
Kees Cook <keescook@chromium.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] lib/int_sqrt.c: optimize for small argument values
Date: Thu, 19 Oct 2017 23:13:47 -0700 [thread overview]
Message-ID: <1508480027.6806.44.camel@perches.com> (raw)
In-Reply-To: <20171019203137.131042-1-md@google.com>
On Thu, 2017-10-19 at 13:31 -0700, Michael Davidson wrote:
> int_sqrt() currently takes approximately constant time
> regardless of the value of the argument. By using the
> magnitude of the operand to set the initial conditions
> for the calculation the cost becomes proportional to
> log2 of the argument with the worst case behavior not
> being measurably slower than it currently is.
https://lkml.org/lkml/2017/7/24/408
next prev parent reply other threads:[~2017-10-20 6:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-19 20:31 Michael Davidson
2017-10-19 20:42 ` Kees Cook
2017-10-19 20:56 ` Jason A. Donenfeld
2017-10-19 21:04 ` Kees Cook
2017-10-20 6:13 ` Joe Perches [this message]
2017-10-20 14:18 ` Kees Cook
2017-10-20 16:22 ` Peter Zijlstra
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=1508480027.6806.44.camel@perches.com \
--to=joe@perches.com \
--cc=akpm@linux-foundation.org \
--cc=davem@davemloft.net \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mawilcox@microsoft.com \
--cc=md@google.com \
--cc=mingo@kernel.org \
/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
Powered by JetHome