Date: Sun, 21 Jan 2007 14:21:41 -0800 From: Luigi Rizzo <rizzo@icir.org> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: Ivan Voras <ivoras@fer.hr>, freebsd-arch@freebsd.org Subject: Re: bzero & bcopy alignment Message-ID: <20070121142141.A83926@xorpc.icir.org> In-Reply-To: <18141.1169417423@critter.freebsd.dk>; from phk@phk.freebsd.dk on Sun, Jan 21, 2007 at 10:10:23PM %2B0000 References: <20070121140019.A83688@xorpc.icir.org> <18141.1169417423@critter.freebsd.dk>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Jan 21, 2007 at 10:10:23PM +0000, Poul-Henning Kamp wrote: > In message <20070121140019.A83688@xorpc.icir.org>, Luigi Rizzo writes: > >On Sun, Jan 21, 2007 at 10:41:09PM +0100, Ivan Voras wrote: > >> Following recent discussion on alignment of bzero() and bcopy(), I've > >> added some statistics collecting code to bzero() and bcopy() for > >> practice (on a RELENG_6 box), and here are the cumulative results for > >> argument alignment: > > > >i think these profiles depend heavily on the hardware > >and usage patterns. > > Undoubtedly, but on the other hand, a lot of them operate on > structs and other data laid out by the compiler, so the > unaligned calls are special cases. and that is why i suggested to instrument the functions to record where in the source the unaligned functions are called, so we can figure out whether it is something unavoidable or something that can be fixed. cheers luigi
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070121142141.A83926>