Date: Fri, 13 Nov 2009 03:02:45 +1100 (EST) From: Bruce Evans <brde@optusnet.com.au> To: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no> Cc: src-committers@FreeBSD.org, d@delphij.net, Peter Jeremy <peterjeremy@acm.org>, svn-src-all@FreeBSD.org, Xin LI <delphij@FreeBSD.org>, Bruce Evans <brde@optusnet.com.au>, svn-src-head@FreeBSD.org Subject: Re: svn commit: r198848 - head/bin/ps Message-ID: <20091113022937.P1408@besplex.bde.org> In-Reply-To: <86d43n23r0.fsf@ds4.des.no> References: <200911030928.nA39SjLx085597@svn.freebsd.org> <20091103214231.H23957@delplex.bde.org> <4AF4B6B2.3090706@delphij.net> <20091111230915.B3510@besplex.bde.org> <20091112050515.GA15002@server.vk2pj.dyndns.org> <86d43n23r0.fsf@ds4.des.no>
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This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --0-1144117182-1258041765=:1408 Content-Type: TEXT/PLAIN; charset=X-UNKNOWN; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE On Thu, 12 Nov 2009, [utf-8] Dag-Erling Sm=C3=B8rgrav wrote: > Peter Jeremy <peterjeremy@acm.org> writes: >> Actually, %4.0f works up to 9999.5 %CPU because there's no '.' in the >> result. I think this is an excellent solution. And since FreeBSD >> currently has a hard limit of 64 CPUs, it's unlikely to be exceeded >> for a while. > > ...if by "a while" you mean "a year or two", because I can't imagine > that restriction surviving much longer than that. You can already get > off-the-shelf hardware with 64 threads per die. Can you imagine NCPU hitting a power wall or other technical barrier at not much larger than 64? > If screen real-estate > is a concern, we can switch the scale from 100 to 1, so 1.0 is full tilt > on one thread, etc., and use "%.5g", which should work for up to 99999 > threads (9999900%) The extra character needed for this is one of the smallest problems resulting from NCPU being huge. The problem expands like O(log(NCPU)) and causes a non-fatal formatting error when it occurs. Other problems expand like O(NCPU). A nearby one is the "pigs" display in systat. This wants to display a on single screen without scrolling, so it will soon take a 6 metre high display to fit just the idle pigs on a 1024- CPU system. These take at most 100% CPU each so they will be sorted after multi-threaded pigs taking more, but they will be sorted before most single-threaded pigs, thus displacing the latter from the window except with > 6 meter high displays. Bruce --0-1144117182-1258041765=:1408--
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