Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 7 Apr 2015 03:58:24 +1000 (EST)
From:      Bruce Evans <brde@optusnet.com.au>
To:        Adrian Chadd <adrian@freebsd.org>
Cc:        "src-committers@freebsd.org" <src-committers@freebsd.org>, Eitan Adler <eadler@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, Kurt Lidl <lidl@pix.net>, Bruce Evans <brde@optusnet.com.au>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>
Subject:   Re: svn commit: r281103 - head/sys/amd64/amd64
Message-ID:  <20150407034210.W13160@besplex.bde.org>
In-Reply-To: <CAJ-Vmom2tF3fxQYDXNVr8L1RCdKRa1zrhGzbBeRhP4uJXVFBdg@mail.gmail.com>
References:  <201504050518.t355IFVJ001786@svn.freebsd.org> <20150405163305.A2515@besplex.bde.org> <CAF6rxgkZA=GbyQFhQC63c9z%2By_ki%2Byjt6fZW%2BP9cHve5L=pYoA@mail.gmail.com> <20150406152653.K1066@besplex.bde.org> <CAJ-Vmom2tF3fxQYDXNVr8L1RCdKRa1zrhGzbBeRhP4uJXVFBdg@mail.gmail.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 6 Apr 2015, Adrian Chadd wrote:

> Hi Bruce,
>
> There's been a bunch of research into that field lately.
>
> Eg: http://daim.idi.ntnu.no/masteroppgaver/009/9231/masteroppgave.pdf
>
> The best part (imho)- the length of your USER environment string
> influencing code runtime costs. :)

I fix the latter in an FP benchmark by aligning the stack to a page
boundary, and further adjusting it by a magic amount of a few hundred.
This only works for microbenchmarks, since in general the stack pointer
is too variable for a single adjustment to keep it from hitting things.

Bruce



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20150407034210.W13160>