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Groups > comp.arch.embedded > #26226
| From | Dimiter_Popoff <dp@tgi-sci.com> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: Speaking of Multiprocessing... |
| Date | 2017-03-25 00:42 +0200 |
| Organization | TGI |
| Message-ID | <ob4772$grc$1@dont-email.me> (permalink) |
| References | (2 earlier) <ob298g$677$1@dont-email.me> <lda9dc9mptoamo1l5es3ku2vm71setk14m@4ax.com> <ob2cck$cu5$1@dont-email.me> <0if9dc9uphm9mrvjjstp1s30ah5fdcfd4i@4ax.com> <ob3la6$hgb$1@dont-email.me> |
On 24.3.2017 г. 19:36, rickman wrote: >... > > Why don't I want to add a bit per memory location? If that bit happens > to be free, I'd be silly to let it go to waste. I am not sure a bit per reservation unit will work in a multiprocessor environment (it certainly will on your single core design, obviously). Both the reserved address (range, typically) and the reserving processor will need to know who reserved what. But this is just a "gut feeling", I did not think seriously about it. > > Again, an abbreviation I don't know. What's a TAS? Test And Set, a classic 68k RMW opcoode. Read a byte (just byte size allowed), adjust the Z flag (Z IIRC...) to the state of bit 7 (MSB), then write the byte back with bit 7 set. While doing this the processor provides some means (holds AS asserted on the 68k IIRC) such that the access to the address can not be granted to another processor for the entire duration of the TAS opcode. Looks like in your case a simple bset (again 68k lingo, bit test and set, but on two separate memory accesses, potentially interruptible by another bus master - not by a processor interrupt, it is a single instruction) will do what you need. Dimiter ------------------------------------------------------ Dimiter Popoff, TGI http://www.tgi-sci.com ------------------------------------------------------ http://www.flickr.com/photos/didi_tgi/
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Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-23 18:38 -0400
Re: Speaking of Multiprocessing... Tim Wescott <seemywebsite@myfooter.really> - 2017-03-23 18:19 -0500
Re: Speaking of Multiprocessing... Don Y <blockedofcourse@foo.invalid> - 2017-03-23 16:26 -0700
Re: Speaking of Multiprocessing... Tim Wescott <seemywebsite@myfooter.really> - 2017-03-23 18:47 -0500
Re: Speaking of Multiprocessing... Don Y <blockedofcourse@foo.invalid> - 2017-03-23 17:49 -0700
Re: Speaking of Multiprocessing... upsidedown@downunder.com - 2017-03-24 09:48 +0200
Re: Speaking of Multiprocessing... Don Y <blockedofcourse@foo.invalid> - 2017-03-24 01:22 -0700
Re: Speaking of Multiprocessing... Clifford Heath <no.spam@please.net> - 2017-03-24 21:04 +1100
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-24 22:01 -0500
Re: Speaking of Multiprocessing... Clifford Heath <no.spam@please.net> - 2017-03-25 18:49 +1100
Re: Speaking of Multiprocessing... Grant Edwards <invalid@invalid.invalid> - 2017-03-24 14:36 +0000
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-23 22:43 -0500
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 01:05 -0400
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-24 00:37 -0500
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 01:58 -0400
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-24 02:07 -0500
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 13:36 -0400
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 19:06 +0100
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 14:12 -0400
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-25 01:48 +0100
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 22:10 -0400
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-25 15:25 +0100
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-25 15:27 -0400
Re: Speaking of Multiprocessing... upsidedown@downunder.com - 2017-03-25 22:43 +0200
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-25 17:06 -0400
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-26 17:28 +0200
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-26 13:27 -0400
Re: Speaking of Multiprocessing... Dimiter_Popoff <dp@tgi-sci.com> - 2017-03-25 00:42 +0200
Re: Speaking of Multiprocessing... rickman <gnuarm@gmail.com> - 2017-03-24 19:22 -0400
Re: Speaking of Multiprocessing... Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2017-03-24 16:33 -0700
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-24 22:47 -0500
Re: Speaking of Multiprocessing... Dimiter_Popoff <dp@tgi-sci.com> - 2017-03-25 12:40 +0200
Re: Speaking of Multiprocessing... Robert Wessel <robertwessel2@yahoo.com> - 2017-03-26 00:42 -0500
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 09:17 +0100
Re: Speaking of Multiprocessing... Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-24 09:28 +0000
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 11:19 +0100
Re: Speaking of Multiprocessing... Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-24 11:06 +0000
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 12:21 +0100
Re: Speaking of Multiprocessing... Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-24 16:09 +0000
Re: Speaking of Multiprocessing... David Brown <david.brown@hesbynett.no> - 2017-03-24 17:33 +0100
Re: Speaking of Multiprocessing... Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-03-24 17:52 +0000
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