Date: Tue, 26 Feb 2002 16:27:51 -0800 (PST) From: Jorge Aldana <jorge@salk.edu> To: Garance A Drosihn <drosih@rpi.edu> Cc: Bob Van Valzah <Bob@Talarian.Com>, <smp@FreeBSD.ORG> Subject: Re: Performance vs. Stable Message-ID: <20020226162616.E32126-100000@merckx.salk.edu> In-Reply-To: <p0510140db8a1ba41ee62@[128.113.24.47]>
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Why isn't WITNESS and WITNESS_SKIPSPIN in LINT? Or is it undocumented? While I'm at it what are they, if you know. Jorge On Tue, 26 Feb 2002, Garance A Drosihn wrote: > At 2:12 PM -0600 2/26/02, Bob Van Valzah wrote: > >Yes, good point, sorry. I shouldn't've glossed over that. > > > >The short answer is that I used GENERIC kernels with as few changes > >as possible. So on -CURRENT, the kernel I tested with was running > >INVARIANTS, INVARIANT_SUPPORT, WITNESS, and WITNESS_SKIPSPIN. These > >were not set on my test -STABLE kernel since they're not set in > >GENERIC there. > > The thing is, -STABLE doesn't need all the extra sanity-checking > code, so it is not compiled in. But with all the wide-ranging > changes going on in -CURRENT, it is much more important to have > the extra checking. > > >If these settings are causing large differences in timings, I think > >it'll show up when I compare kgmon/gprof results between kernels. I > >can also just compile a kernel without these settings and see how it > >differs. > > You will find that these settings make a huge difference in the > timings of many things. > > >I'm still very new to this so I'm trying to map the benchmarking > >space and see where there are interesting questions. You've opened > >my eyes to an area I'd missed but should've seen. Are there others? > > Probably, but I don't know enough to say what they are... :-) > > -- > Garance Alistair Drosehn = gad@eclipse.acs.rpi.edu > Senior Systems Programmer or gad@freebsd.org > Rensselaer Polytechnic Institute or drosih@rpi.edu > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-smp" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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