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| From | James Kuyper <jameskuyper@verizon.net> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: I want to ask a question... |
| Date | 2015-08-20 23:24 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <mr65hq$1eb$1@dont-email.me> (permalink) |
| References | (7 earlier) <mr5043$gfe$1@speranza.aioe.org> <mr514a$688$1@dont-email.me> <slrnmtc48b.vvc.tTh@hangartistique.cispeo.fr> <mr59jh$b5v$1@dont-email.me> <mr5evc$24a$1@dont-email.me> |
On 08/20/2015 04:58 PM, David Brown wrote: ... > I believe it is common for malloc implementations to ask the OS for > large chunks of memory, then dish out parts of that as needed by the > program. This way they only bother the OS on occasion, and the overhead > for malloc is much smaller (there are no context switches or system > calls for most allocations). Memory can only be returned to the OS if a > whole chunk has been freed - ... I agree with all of the above. > ... and if the program has a mix of malloc's > and free's, that is rarely going to happen. It needs a program that has > allocated a substantial amount of memory, freed it, and then continues > running for a significant time without re-using that memory space. That doesn't strike me as a particular odd thing for a program to do. I've seen programs that have a memory-intensive set-up phase, after which they spend a lot of time waiting (sometimes for days or weeks at a time) for events to happen and reacting to them, without needing anywhere near as much memory. If I were using such a program, I'd be very upset that it was monopolizing it's entire initial memory requirement for the entire life of the program. Of course, a lot of modern software hogs a lot of memory, and possibly this is one of the reasons why. That pattern is not typical of the programs I write: they aren't event driven, and typically have a set-up phase that uses far less memory than the main processing phase, not more. But I'm very aware that other patterns exist. -- James Kuyper
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Re: I want to ask a question... Gareth Owen <gwowen@gmail.com> - 2015-08-07 20:00 +0100
Re: I want to ask a question... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-07 19:04 +0000
Re: I want to ask a question... Keith Thompson <kst-u@mib.org> - 2015-08-07 15:30 -0700
Re: I want to ask a question... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-07 22:52 +0000
Re: I want to ask a question... Keith Thompson <kst-u@mib.org> - 2015-08-07 16:46 -0700
Re: I want to ask a question... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-07 23:29 +0000
Re: I want to ask a question... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-08-08 01:37 +0100
Re: I want to ask a question... Keith Thompson <kst-u@mib.org> - 2015-08-07 18:55 -0700
Re: I want to ask a question... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-08 05:51 +0000
Re: I want to ask a question... Robert Wessel <robertwessel2@yahoo.com> - 2015-08-08 01:44 -0500
Re: I want to ask a question... Ken Brody <kenbrody@spamcop.net> - 2015-08-10 12:46 -0400
Re: I want to ask a question... supercat@casperkitty.com - 2015-08-19 16:43 -0700
Re: I want to ask a question... Keith Thompson <kst-u@mib.org> - 2015-08-19 18:09 -0700
Re: I want to ask a question... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-20 01:00 +0000
Re: I want to ask a question... Keith Thompson <kst-u@mib.org> - 2015-08-19 20:25 -0700
Re: I want to ask a question... supercat@casperkitty.com - 2015-08-20 08:15 -0700
Re: I want to ask a question... Keith Thompson <kst-u@mib.org> - 2015-08-20 11:38 -0700
Re: I want to ask a question... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-20 18:47 +0000
Re: I want to ask a question... supercat@casperkitty.com - 2015-08-20 14:01 -0700
Re: I want to ask a question... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-20 16:43 +0000
Re: I want to ask a question... James Kuyper <jameskuyper@verizon.net> - 2015-08-20 13:02 -0400
Re: I want to ask a question... Tonton Th <tTh@nowhere.invalid> - 2015-08-20 17:40 +0000
Re: I want to ask a question... James Kuyper <jameskuyper@verizon.net> - 2015-08-20 15:27 -0400
Re: I want to ask a question... David Brown <david.brown@hesbynett.no> - 2015-08-20 22:58 +0200
Re: I want to ask a question... James Kuyper <jameskuyper@verizon.net> - 2015-08-20 23:24 -0400
Re: I want to ask a question... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-21 06:19 +0000
Re: I want to ask a question... Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2015-08-21 09:20 -0600
Re: I want to ask a question... supercat@casperkitty.com - 2015-08-22 12:25 -0700
Re: I want to ask a question... Robert Wessel <robertwessel2@yahoo.com> - 2015-08-23 01:33 -0500
Re: I want to ask a question... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-20 19:28 +0000
Re: I want to ask a question... Keith Thompson <kst-u@mib.org> - 2015-08-20 12:11 -0700
Re: I want to ask a question... David Brown <david.brown@hesbynett.no> - 2015-08-20 10:02 +0200
Re: I want to ask a question... raltbos@xs4all.nl (Richard Bos) - 2015-08-22 13:42 +0000
Re: I want to ask a question... supercat@casperkitty.com - 2015-08-22 12:23 -0700
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