Date: Sun, 23 Jul 2006 20:57:59 +0200 (CEST) From: sthaug@nethelp.no To: lists@wm-access.no Cc: freebsd-current@freebsd.org, imp@bsdimp.com Subject: Re: vmstat's entries type Message-ID: <20060723.205759.74723866.sthaug@nethelp.no> In-Reply-To: <44C3B674.3040804@wm-access.no> References: <200607191315.k6JDFpvM048354@lurza.secnetix.de> <20060720.093457.1661914908.imp@bsdimp.com> <44C3B674.3040804@wm-access.no>
next in thread | previous in thread | raw e-mail | index | archive | help
> > One approach that we could use for 64-bit counters would be to just > > use 32-bits one, and poll them for overflow and bump an overflow > > count. This assumes that the 32-bit counters overflow much less often > > than the polling interval, and easily triples the amount of storage > > for each of them... It is ugly :-( > > > > What's wrong with the add+adc (asm) approach found on any i386? Presumably the fact that add + adc isn't an atomic operation. So if you want to guarantee 64 bit consistency, you need locking or similar. Steinar Haug, Nethelp consulting, sthaug@nethelp.no
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20060723.205759.74723866.sthaug>