Date: Tue, 18 Sep 2007 19:18:05 -0700 (PDT) From: Jeff Roberson <jroberson@chesapeake.net> To: Garrett Wollman <wollman@hergotha.csail.mit.edu> Cc: arch@freebsd.org Subject: Re: 64bit ticks, was Re: Changing p_swtime and td_slptime to ticks Message-ID: <20070918191527.C558@10.0.0.1> In-Reply-To: <200709190143.l8J1hJKA074148@hergotha.csail.mit.edu> References: <20070917165657.B558@10.0.0.1> <46EF644E.9050207@elischer.org> <20070918012555.G558@10.0.0.1> <46EFE4BD.4030505@freebsd.org> <20070918142115.C558@10.0.0.1> <200709190143.l8J1hJKA074148@hergotha.csail.mit.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 18 Sep 2007, Garrett Wollman wrote: > Jeff Roberson writes: > >> Is there a good reason for not making ticks 64bit? math involving this >> value is relatively infrequent. Bruce? Any comments? It'd sure let us >> forget all of these counter wrapping problems. > > Making ticks 64 bits on 32-bit architectures means that updates to it > will not be atomic. You're right. There would be a chance that you'd get mismatched upper and lower halves on wrap conditions and would have to detect accordingly. That's probably too much trouble. Thanks, Jeff > > -GAWollman > > -- > Garrett A. Wollman | The real tragedy of human existence is not that we are > wollman@csail.mit.edu| nasty by nature, but that a cruel structural asymmetry > Opinions not those | grants to rare events of meanness such power to shape > of MIT or CSAIL. | our history. - S.J. Gould, Ten Thousand Acts of Kindness >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070918191527.C558>