Re: top memory usage question
On Thu, May 27, 2010 at 12:52 PM, Coert wrote: > Hello all, > > Just a question, on Linux the output of top's memory usage looks like this: > > Mem: 2075424k total, 1760848k used, 314576k free, 151872k buffers > Swap: 4192924k total, 0k used, 4192924k free, 1214052k cached > > > on FreeBSD: > > Mem: 48M Active, 945M Inact, 190M Wired, 112M Buf, 804M Free > Swap: 4063M Total, 4063M Free > > > I have looked at the respective man pages, and googled. > Where can I find out what Active, Inactive, and Wired mean? > The differences have to do with the way memory is managed. Active memory is currently is RAM and is being used by a currently running process. Inactive is in RAM but is not currently being used. Wired means that the page is locked into ram and won't be paged out. Look at http://en.wikipedia.org/wiki/Paging and http://en.wikipedia.org/wiki/Virtual_memory for more info -- Eitan Adler ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: top memory usage question
On Thu, 27 May 2010 11:52:15 +0200 Coert wrote: > Hello all, > > Just a question, on Linux the output of top's memory usage looks like > this: > > Mem: 2075424k total, 1760848k used, 314576k free, 151872k > buffers Swap: 4192924k total,0k used, 4192924k free, > 1214052k cached > > > on FreeBSD: > > Mem: 48M Active, 945M Inact, 190M Wired, 112M Buf, 804M Free > Swap: 4063M Total, 4063M Free This is missing Cache > I have looked at the respective man pages, and googled. > Where can I find out what Active, Inactive, and Wired mean? Active, Inact, Cache , and Free are all part of the same VM lifecycle. When the system need to allocate memory it comes from cache or free. Wired memory wont be paged-out. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
top memory usage question
Hello all, Just a question, on Linux the output of top's memory usage looks like this: Mem: 2075424k total, 1760848k used, 314576k free, 151872k buffers Swap: 4192924k total,0k used, 4192924k free, 1214052k cached on FreeBSD: Mem: 48M Active, 945M Inact, 190M Wired, 112M Buf, 804M Free Swap: 4063M Total, 4063M Free I have looked at the respective man pages, and googled. Where can I find out what Active, Inactive, and Wired mean? Thank you, Coert ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: memory usage question
On Tue, Aug 17, 2004 at 03:39:40PM +0200, Mipam wrote: > I have a question about usage of memory. > Despite the well documented articles about it some things are still > unclear. In top we see memory devided in several items: Try this article, buy the guy who wrote some very large chunks of the VM system: http://www.daemonnews.org/21/freebsd_vm.html As for the meaning of the different labels top(1) shows attached to memory sizes: those indicate a sequence of memory caches for different age levels of pages. Note that the system doesn't overwrite cached pages on a timed basis, but rather picks the oldest unused memory to recycle as and when some other application requests it. Stuff can stay in the memory caches for a very long time on a quiet system. http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/misc.html#TOP-FREEMEM Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK pgpJznDRYHpps.pgp Description: PGP signature
memory usage question
Hi, I have a question about usage of memory. Despite the well documented articles about it some things are still unclear. In top we see memory devided in several items: Active, inactive, buffered, wired and free. The active memory is clear, it's what is in use by programs now. Wired mem is also clear, it's for the kernel data structs. When a program ends, the mem is put in the inactive part right? So when the program is run 10 minutes after it can be started very quickly, also because the data used from the disk of that program is still in the cache part right? However, suppose the program isnt run in 2 hours, will there be a timeout in the parts which are being put in inactive and in cache? Suppose the timeout has occured, will the mem be added to free mem or? What is the difference between buffered mem and cached mem? Both represent data which is recently being called from the disk, so that next time when the file is called again, no disk access, needs to be made in order to save time right? However, suppose i have little mem free, say 7 mb and still 200 in inactive. Then a program needs to start which needs say 30 mb on mem, will also mem be taken from the inactive part and discard the cache? Some ppl only look at how much free mem is available on their system and then sound the alarm, however, shouldnt they add inactive and free together in order to see how much mem can be used for newly used programs (which didnt run before?). Bye, Mipam. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
