From mboxrd@z Thu Jan 1 00:00:00 1970 From: grog@lemis.com (Greg 'groggy' Lehey) Date: Sat, 2 Oct 2010 13:46:01 +1000 Subject: [TUHS] PDP-8 (was: 2.11BSD cross compiler) In-Reply-To: <20100930135029.GB30928@bitmover.com> References: <20100929005148.GA8032@bitmover.com> <20100929023819.GA12919@bitmover.com> <20100930042229.GA66070@dereel.lemis.com> <20100930135029.GB30928@bitmover.com> Message-ID: <20101002034601.GE66070@dereel.lemis.com> On Thursday, 30 September 2010 at 6:50:29 -0700, Larry McVoy wrote: >>>>  If you don't get the question you are not an OS person, >>>> if you are, of course you get it. >> >> Hmm. Am I expected to understand this? Seriously, I don't know how >> many people really wrote anything like swtch (). > > You'd be amazed at how many people did their own user level threads. > Gotta write swtch() for that. I think you're missing the joke. But swtch () is a specific kernel function in UNIX, though in this thread (excuse the pun) people seem to be using it as a synonym for a scheduler. And not many people need to write their threading library by hand any more. > And it's not swtch() so much as do you understand the stack frames? That's a different issue. Any programmer worth his salt needs to understand the underlying hardware, including stack frames. For my personal understanding of them, see http://www.lemis.com/grog/Documentation/PUS/porting_unix_software/obj.pdf towards the end, or http://www.lemis.com/grog/Papers/Debug-tutorial/ for the kernel context, page 17 on. > If you could look at the stack frames and give me a stack trace > that's more or less the same thing. (gdb) bt The real question is not to get a stack trace, but to analyse it. Greg -- Finger grog at FreeBSD.org for PGP public key. See complete headers for address and phone numbers. This message is digitally signed. See http://www.lemis.com/grog/email/signed-mail.php for more details. If your Microsoft MUA reports problems, please read http://tinyurl.com/broken-mua -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 195 bytes Desc: not available URL: