Date: Sat, 30 Nov 2002 18:25:50 +1100 (EST) From: Bruce Evans <bde@zeta.org.au> To: David Syphers <dsyphers@uchicago.edu> Cc: Kris Kennaway <kris@obsecurity.org>, <freebsd-current@FreeBSD.ORG> Subject: Re: 5.0-DP2 questions Message-ID: <20021130180108.F3539-100000@gamplex.bde.org> In-Reply-To: <200211291304.47766.dsyphers@uchicago.edu>
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On Fri, 29 Nov 2002, David Syphers wrote: > On Friday 29 November 2002 12:12 pm, Kris Kennaway wrote: > > On Fri, Nov 29, 2002 at 12:11:42PM -0500, Robert Ames wrote: > > > > > 2. My machine is a Pentium 166 with only 16 MB of RAM. I'm trying > > > to rebuild the kernel and so far the compile has been running for > > > almost 24 hours and it's not finished yet. Is this to be expected? > > > > Yes. gcc 3.x is slower, and the kernel contains more code. Your > > machine is probably swapping a lot just doing the compilation, which > > will make it even slower. > > Out of curiosity, how much slower is a 5.x kernel compilation than a 4.x, on > average? I'm not sure about 4.x, but a -current kernel with no modules takes about 3 times as long as a RELENG_3 kernel compiled by the 4.x compiler used to take (about 130 seconds instead of 43 seconds on an Athlon 1600 overclocked. The kernels are supposed to have a similar set of options. All times are all times are after running "make depend" which takes about 8 seconds for RELENG_3 and 11 seconds for -current. gcc-3 in April 2002 pessimized the compile times from 76 seconds to 114 seconds for -current and from 43 seconds to 66 seconds for RELENG_3. Further development of -current pessimized the compile time from 114 seconds to 130 seconds. Compiling LINT took 437 seconds on Sep 22. IIRC, compiling modules takes about the same time as compiling LINT. > My 486, 66 MHz and 16 MB RAM, compiles a 4.x kernel in about 3 > hours. Thus by Robert's data point, -current seems at least 10-15 times > slower... Ouch. I remember being happy when upgrading from a 486/33 with 16MB to a 486DX2/66 with 32MB reduced my kernel compile time from about 16 minutes to about 9 minutes. Your 16MB of RAM is probably not nearly enough for today's bloat. Look at the real, user and system times and systat/vmstat/top to see if there is a lot of idle time caused by waiting for disks and/or paging to disk. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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