* Re: VM Vs Swap space [not found] ` <20041007160656.32450.qmail@web52904.mail.yahoo.com> @ 2004-10-07 16:13 ` Pratik Solanki 0 siblings, 0 replies; 17+ messages in thread From: Pratik Solanki @ 2004-10-07 16:13 UTC (permalink / raw) To: Ankit Jain; +Cc: linux-newbie Yes. 32 bit address = 2^32 addresses = 4GB For a 64-bit machine, the limit is 2^64. Pratik. On Thu, 7 Oct 2004 17:06:56 +0100 (BST), Ankit Jain <ankitjain1580@yahoo.com> wrote: > why limit is upto 4 GB is it due to address bus limit? > > thanks > > ankit > --- Pratik Solanki <pratik.solanki.ml@gmail.com> > wrote: > > > > On Thu, 7 Oct 2004 10:37:40 +0100 (BST), Ankit Jain > > <ankitjain1580@yahoo.com> wrote: > > > well if we dont have a swap area then shall i say > > my > > > system dosent have virtual memory > > > > No. > > > > > is this correct? because i feel even if this swap > > area > > > is not there then also virtual memory concept > > exists? > > > > Virtual memory is the reason why applications can > > think they have 4GB > > of memory while your physical machine might actually > > have only 32MB. > > You don't need to have swap in order to have virtual > > memory, although > > its very advantageous to have swap with VM. > > > > Virtual memory maps the viurtual pages (from 0 to > > 4GB) to actually > > physical memory pages (from 0 to however much RAM > > you have). Swapping > > is the process of using the disk to store physical > > memory pages when > > they are not in use, and then restoring them when an > > application > > accesses them. > > > > Pratik. > > > > ________________________________________________________________________ > Yahoo! Messenger - Communicate instantly..."Ping" > your friends today! Download Messenger Now > http://uk.messenger.yahoo.com/download/index.html > - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* VM Vs Swap space @ 2004-10-06 8:52 Ankit Jain 2004-10-07 1:57 ` chuck gelm 0 siblings, 1 reply; 17+ messages in thread From: Ankit Jain @ 2004-10-06 8:52 UTC (permalink / raw) To: newbie hi if somebody can tell me that is this correct? can i say that swap area created by linux is nothign but virtual memory. is it correct to use the term interchangeably thanks ankit ________________________________________________________________________ Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now http://uk.messenger.yahoo.com/download/index.html - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-06 8:52 Ankit Jain @ 2004-10-07 1:57 ` chuck gelm 2004-10-07 6:01 ` kernel kernel 2004-10-07 9:15 ` Ankit Jain 0 siblings, 2 replies; 17+ messages in thread From: chuck gelm @ 2004-10-07 1:57 UTC (permalink / raw) To: Ankit Jain; +Cc: newbie Ankit Jain wrote: >hi > >if somebody can tell me that is this correct? > >(1)can i say that swap area created by linux is nothign >but virtual memory. (2)is it correct to use the term >interchangeably > >thanks > >ankit > > (1) A swap file or swap partition can be used as virtual memory. (2) I am not sure. Why one would wish to use 'swap area' interchangeably with 'virtual memory'. :-| Chuck - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 1:57 ` chuck gelm @ 2004-10-07 6:01 ` kernel kernel 2004-10-07 9:15 ` Ankit Jain 1 sibling, 0 replies; 17+ messages in thread From: kernel kernel @ 2004-10-07 6:01 UTC (permalink / raw) To: chuck; +Cc: Ankit Jain, newbie swap area forms a part of the memory which is used for the memory objects like the stack when executable starts running. This anonymous segment will grow dependin upon the pattern of the functions calls in ur executable On Wed, 06 Oct 2004 21:57:27 -0400, chuck gelm <chuck@gelm.net> wrote: > Ankit Jain wrote: > > >hi > > > >if somebody can tell me that is this correct? > > > >(1)can i say that swap area created by linux is nothign > >but virtual memory. (2)is it correct to use the term > >interchangeably > > > >thanks > > > >ankit > > > > > (1) A swap file or swap partition can be used as virtual memory. > (2) I am not sure. Why one would wish to use 'swap area' > interchangeably with 'virtual memory'. > :-| > Chuck > > > > > - > To unsubscribe from this list: send the line "unsubscribe linux-newbie" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.linux-learn.org/faqs > - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 1:57 ` chuck gelm 2004-10-07 6:01 ` kernel kernel @ 2004-10-07 9:15 ` Ankit Jain 2004-10-07 9:25 ` kernel kernel 2004-10-07 10:41 ` chuck gelm 1 sibling, 2 replies; 17+ messages in thread From: Ankit Jain @ 2004-10-07 9:15 UTC (permalink / raw) To: chuck; +Cc: newbie how will u differentiate virtual memory and swap area thanks ankit --- chuck gelm <chuck@gelm.net> wrote: > Ankit Jain wrote: > > >hi > > > >if somebody can tell me that is this correct? > > > >(1)can i say that swap area created by linux is > nothign > >but virtual memory. (2)is it correct to use the > term > >interchangeably > > > >thanks > > > >ankit > > > > > (1) A swap file or swap partition can be used as > virtual memory. > (2) I am not sure. Why one would wish to use 'swap > area' > interchangeably with 'virtual memory'. > :-| > Chuck > > > ________________________________________________________________________ Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now http://uk.messenger.yahoo.com/download/index.html - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 9:15 ` Ankit Jain @ 2004-10-07 9:25 ` kernel kernel 2004-10-07 9:37 ` Ankit Jain 2004-10-07 10:41 ` chuck gelm 1 sibling, 1 reply; 17+ messages in thread From: kernel kernel @ 2004-10-07 9:25 UTC (permalink / raw) To: Ankit Jain; +Cc: chuck, newbie Virtual Memory is a policy. Swap Area is a artifact, u use to implement this policy Hope makes sense On Thu, 7 Oct 2004 10:15:15 +0100 (BST), Ankit Jain <ankitjain1580@yahoo.com> wrote: > how will u differentiate virtual memory and swap area > > thanks > > ankit > --- chuck gelm <chuck@gelm.net> wrote: > > Ankit Jain wrote: > > > > >hi > > > > > >if somebody can tell me that is this correct? > > > > > >(1)can i say that swap area created by linux is > > nothign > > >but virtual memory. (2)is it correct to use the > > term > > >interchangeably > > > > > >thanks > > > > > >ankit > > > > > > > > (1) A swap file or swap partition can be used as > > virtual memory. > > (2) I am not sure. Why one would wish to use 'swap > > area' > > interchangeably with 'virtual memory'. > > :-| > > Chuck > > > > > > > > ________________________________________________________________________ > Yahoo! Messenger - Communicate instantly..."Ping" > your friends today! Download Messenger Now > http://uk.messenger.yahoo.com/download/index.html > > > - > To unsubscribe from this list: send the line "unsubscribe linux-newbie" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.linux-learn.org/faqs > - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 9:25 ` kernel kernel @ 2004-10-07 9:37 ` Ankit Jain 2004-10-07 10:31 ` chuck gelm ` (2 more replies) 0 siblings, 3 replies; 17+ messages in thread From: Ankit Jain @ 2004-10-07 9:37 UTC (permalink / raw) To: kernel kernel; +Cc: newbie well if we dont have a swap area then shall i say my system dosent have virtual memory is this correct? because i feel even if this swap area is not there then also virtual memory concept exists? thanks ankit --- kernel kernel <unix.hacker@gmail.com> wrote: > Virtual Memory is a policy. Swap Area is a > artifact, u use to > implement this policy > > Hope makes sense > > > On Thu, 7 Oct 2004 10:15:15 +0100 (BST), Ankit Jain > <ankitjain1580@yahoo.com> wrote: > > how will u differentiate virtual memory and swap > area > > > > thanks > > > > ankit > > --- chuck gelm <chuck@gelm.net> wrote: > > > Ankit Jain wrote: > > > > > > >hi > > > > > > > >if somebody can tell me that is this correct? > > > > > > > >(1)can i say that swap area created by linux is > > > nothign > > > >but virtual memory. (2)is it correct to use the > > > term > > > >interchangeably > > > > > > > >thanks > > > > > > > >ankit > > > > > > > > > > > (1) A swap file or swap partition can be used as > > > virtual memory. > > > (2) I am not sure. Why one would wish to use > 'swap > > > area' > > > interchangeably with 'virtual memory'. > > > :-| > > > Chuck > > > > > > > > > > > > > > ________________________________________________________________________ > > Yahoo! Messenger - Communicate instantly..."Ping" > > your friends today! Download Messenger Now > > http://uk.messenger.yahoo.com/download/index.html > > > > > > - > > To unsubscribe from this list: send the line > "unsubscribe linux-newbie" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at > http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at > http://www.linux-learn.org/faqs > > > ________________________________________________________________________ Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now http://uk.messenger.yahoo.com/download/index.html - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 9:37 ` Ankit Jain @ 2004-10-07 10:31 ` chuck gelm 2004-10-07 16:05 ` Pratik Solanki 2004-10-07 16:07 ` Pratik Solanki 2 siblings, 0 replies; 17+ messages in thread From: chuck gelm @ 2004-10-07 10:31 UTC (permalink / raw) To: Ankit Jain; +Cc: kernel kernel, newbie Ankit Jain wrote: >well if we dont have a swap area then shall i say my >system dosent have virtual memory > > Yes, I think so. I think that it is difficult to say that a system has no 'swap area', because a 'swap area' could be a file. How can you be sure that none of the files on a system are a 'swap file' ? I think that you can say that a system has no 'swap' or 'virtual memory' if there are no swap areas enabled. I suggest that the output of 'free' will indicate your swap. If 'free' indicates that you have no swap, then you have no swap. If 'free' indicates that you have swap, then you have swap. >is this correct? because i feel even if this swap area >is not there then also virtual memory concept exists? > A system can have a swap partition and not use it. A system can have a swap file and not use it. Swap can be enabled and disabled on a running kernel. So, at any given instance, a running system can have or have not 'virtual memory'. >thanks > >ankit >--- kernel kernel <unix.hacker@gmail.com> wrote: > > >>Virtual Memory is a policy. Swap Area is a >>artifact, u use to >>implement this policy >> >>Hope makes sense >> >> >>On Thu, 7 Oct 2004 10:15:15 +0100 (BST), Ankit Jain >><ankitjain1580@yahoo.com> wrote: >> >> >>>how will u differentiate virtual memory and swap >>> >>> >>area >> >> >>>thanks >>> >>>ankit >>>--- chuck gelm <chuck@gelm.net> wrote: >>> >>> >>>>Ankit Jain wrote: >>>> >>>> >>>> >>>>>hi >>>>> >>>>>if somebody can tell me that is this correct? >>>>> >>>>>(1)can i say that swap area created by linux is >>>>> >>>>> >>>>nothign >>>> >>>> >>>>>but virtual memory. (2)is it correct to use the >>>>> >>>>> >>>>term >>>> >>>> >>>>>interchangeably >>>>> >>>>>thanks >>>>> >>>>>ankit >>>>> >>>>> >>>>> >>>>> >>>>(1) A swap file or swap partition can be used as >>>>virtual memory. >>>>(2) I am not sure. Why one would wish to use >>>> >>>> >>'swap >> >> >>>>area' >>>>interchangeably with 'virtual memory'. >>>>:-| >>>>Chuck >>>> >>>> - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 9:37 ` Ankit Jain 2004-10-07 10:31 ` chuck gelm @ 2004-10-07 16:05 ` Pratik Solanki 2004-10-07 16:07 ` Pratik Solanki 2 siblings, 0 replies; 17+ messages in thread From: Pratik Solanki @ 2004-10-07 16:05 UTC (permalink / raw) To: linux-newbie On Thu, 7 Oct 2004 10:37:40 +0100 (BST), Ankit Jain <ankitjain1580@yahoo.com> wrote: > well if we dont have a swap area then shall i say my > system dosent have virtual memory No. > is this correct? because i feel even if this swap area > is not there then also virtual memory concept exists? Virtual memory is the reason why applications can think they have 4GB of memory while your physical machine might actually have only 32MB. You don't need to have swap in order to have virtual memory, although its very advantageous to have swap with VM. Virtual memory maps the viurtual pages (from 0 to 4GB) to actually physical memory pages (from 0 to however much RAM you have). Swapping is the process of using the disk to store physical memory pages when they are not in use, and then restoring them when an application accesses them. - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 9:37 ` Ankit Jain 2004-10-07 10:31 ` chuck gelm 2004-10-07 16:05 ` Pratik Solanki @ 2004-10-07 16:07 ` Pratik Solanki 2004-10-08 3:29 ` kernel kernel 2 siblings, 1 reply; 17+ messages in thread From: Pratik Solanki @ 2004-10-07 16:07 UTC (permalink / raw) To: linux-newbie On Thu, 7 Oct 2004 10:37:40 +0100 (BST), Ankit Jain <ankitjain1580@yahoo.com> wrote: > well if we dont have a swap area then shall i say my > system dosent have virtual memory No. > is this correct? because i feel even if this swap area > is not there then also virtual memory concept exists? Virtual memory is the reason why applications can think they have 4GB of memory while your physical machine might actually have only 32MB. You don't need to have swap in order to have virtual memory, although its very advantageous to have swap with VM. Virtual memory maps the viurtual pages (from 0 to 4GB) to actually physical memory pages (from 0 to however much RAM you have). Swapping is the process of using the disk to store physical memory pages when they are not in use, and then restoring them when an application accesses them. Pratik. - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 16:07 ` Pratik Solanki @ 2004-10-08 3:29 ` kernel kernel 0 siblings, 0 replies; 17+ messages in thread From: kernel kernel @ 2004-10-08 3:29 UTC (permalink / raw) To: Pratik Solanki; +Cc: linux-newbie In That case, also. There is a implicit Swap area and a Explicit area. On Thu, 7 Oct 2004 12:07:21 -0400, Pratik Solanki <pratik.solanki.ml@gmail.com> wrote: > On Thu, 7 Oct 2004 10:37:40 +0100 (BST), Ankit Jain > <ankitjain1580@yahoo.com> wrote: > > well if we dont have a swap area then shall i say my > > system dosent have virtual memory > > No. > > > is this correct? because i feel even if this swap area > > is not there then also virtual memory concept exists? > > Virtual memory is the reason why applications can think they have 4GB > of memory while your physical machine might actually have only 32MB. > You don't need to have swap in order to have virtual memory, although > its very advantageous to have swap with VM. > > Virtual memory maps the viurtual pages (from 0 to 4GB) to actually > physical memory pages (from 0 to however much RAM you have). Swapping > is the process of using the disk to store physical memory pages when > they are not in use, and then restoring them when an application > accesses them. > > Pratik. > > > - > To unsubscribe from this list: send the line "unsubscribe linux-newbie" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.linux-learn.org/faqs > - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 9:15 ` Ankit Jain 2004-10-07 9:25 ` kernel kernel @ 2004-10-07 10:41 ` chuck gelm 2004-10-07 16:09 ` Pratik Solanki 1 sibling, 1 reply; 17+ messages in thread From: chuck gelm @ 2004-10-07 10:41 UTC (permalink / raw) To: Ankit Jain; +Cc: newbie Ankit Jain wrote: >how will u differentiate virtual memory and swap area > >thanks > >ankit > > Virtual memory is swap area in use. Regards, Chuck > --- chuck gelm <chuck@gelm.net> wrote: > > >>Ankit Jain wrote: >> >> >> >>>hi >>> >>>if somebody can tell me that is this correct? >>> >>>(1)can i say that swap area created by linux is >>> >>> >>nothign >> >> >>>but virtual memory. (2)is it correct to use the >>> >>> >>term >> >> >>>interchangeably >>> >>>thanks >>> >>>ankit >>> >>> >>> >>> >>(1) A swap file or swap partition can be used as >>virtual memory. >>(2) I am not sure. Why one would wish to use 'swap >>area' >>interchangeably with 'virtual memory'. >>:-| >>Chuck >> >> - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 10:41 ` chuck gelm @ 2004-10-07 16:09 ` Pratik Solanki [not found] ` <20041007172157.63553.qmail@web52908.mail.yahoo.com> 0 siblings, 1 reply; 17+ messages in thread From: Pratik Solanki @ 2004-10-07 16:09 UTC (permalink / raw) To: linux-newbie On Thu, 07 Oct 2004 06:41:38 -0400, chuck gelm <chuck@gelm.net> wrote: > Ankit Jain wrote: > > >how will u differentiate virtual memory and swap area > > > >thanks > > > >ankit > > > > > Virtual memory is swap area in use. umm. A running system can or cannot have swap. Correct me if I am wrong but you can't disable virtual memory once its enabled, or at the very least it would be extremely tough to do so and I don't know of any system that does it. Virtual memory is enabled when the kernel starts up and stays that way. Swap is a different issue. Pratik. - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
[parent not found: <20041007172157.63553.qmail@web52908.mail.yahoo.com>]
* Re: VM Vs Swap space [not found] ` <20041007172157.63553.qmail@web52908.mail.yahoo.com> @ 2004-10-07 18:49 ` Pratik Solanki 2004-10-07 22:13 ` chuck gelm 0 siblings, 1 reply; 17+ messages in thread From: Pratik Solanki @ 2004-10-07 18:49 UTC (permalink / raw) To: Ankit Jain; +Cc: linux-newbie [CCing linux-newbie] On Thu, 7 Oct 2004 18:21:57 +0100 (BST), Ankit Jain <ankitjain1580@yahoo.com> wrote: > well i dont know exactly but somewhat i feel that > there must be some way to disable the virtual memory. > yaa of course there should be some way. it is not that > sys cant work without it Yes, you can have a system without virtual memory. Search for MMUless linux kernel and you'll see patches/websites. My point was that disabling VM after its been enabled would tough (if not impossible). Someone correct me if I am wrong here. Pratik. > ankit > --- Pratik Solanki <pratik.solanki.ml@gmail.com> > wrote: > > > > On Thu, 07 Oct 2004 06:41:38 -0400, chuck gelm > > <chuck@gelm.net> wrote: > > > Ankit Jain wrote: > > > > > > >how will u differentiate virtual memory and swap > > area > > > > > > > >thanks > > > > > > > >ankit > > > > > > > > > > > Virtual memory is swap area in use. > > > > umm. A running system can or cannot have swap. > > Correct me if I am > > wrong but you can't disable virtual memory once its > > enabled, or at the > > very least it would be extremely tough to do so and > > I don't know of > > any system that does it. Virtual memory is enabled > > when the kernel > > starts up and stays that way. Swap is a different > > issue. > > > > Pratik. > > - > > To unsubscribe from this list: send the line > > "unsubscribe linux-newbie" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at > > http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at > > http://www.linux-learn.org/faqs > > > > > > ________________________________________________________________________ > Yahoo! Messenger - Communicate instantly..."Ping" > your friends today! Download Messenger Now > http://uk.messenger.yahoo.com/download/index.html > - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 18:49 ` Pratik Solanki @ 2004-10-07 22:13 ` chuck gelm 2004-10-08 2:49 ` Jim Nelson 2004-10-08 15:25 ` Pratik Solanki 0 siblings, 2 replies; 17+ messages in thread From: chuck gelm @ 2004-10-07 22:13 UTC (permalink / raw) To: Pratik Solanki; +Cc: Ankit Jain, linux-newbie Pratik Solanki wrote: >[CCing linux-newbie] > >On Thu, 7 Oct 2004 18:21:57 +0100 (BST), Ankit Jain ><ankitjain1580@yahoo.com> wrote: > > >>well i dont know exactly but somewhat i feel that >>there must be some way to disable the virtual memory. >>yaa of course there should be some way. it is not that >>sys cant work without it >> >> > >Yes, you can have a system without virtual memory. Search for MMUless >linux kernel and you'll see patches/websites. > >My point was that disabling VM after its been enabled would tough (if >not impossible). Someone correct me if I am wrong here. > >Pratik. > I was thinking that an active swap partition was 'virtual memory'. Why are many folks using capital letters 'VM'. Am I missing something? Is 'VM' == virtual memory or is there a application or service called 'VM' ? Anywho, the only 'virtual memory' I know of is an active swap file or swap partition and either can be started or stopped in a running kernel. (I think.) Regards, Chuck - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 22:13 ` chuck gelm @ 2004-10-08 2:49 ` Jim Nelson 2004-10-08 15:25 ` Pratik Solanki 1 sibling, 0 replies; 17+ messages in thread From: Jim Nelson @ 2004-10-08 2:49 UTC (permalink / raw) To: chuck; +Cc: Pratik Solanki, Ankit Jain, linux-newbie chuck gelm wrote: > Pratik Solanki wrote: > >> [CCing linux-newbie] >> >> On Thu, 7 Oct 2004 18:21:57 +0100 (BST), Ankit Jain >> <ankitjain1580@yahoo.com> wrote: >> >> >>> well i dont know exactly but somewhat i feel that >>> there must be some way to disable the virtual memory. >>> yaa of course there should be some way. it is not that >>> sys cant work without it >>> >> >> >> Yes, you can have a system without virtual memory. Search for MMUless >> linux kernel and you'll see patches/websites. >> >> My point was that disabling VM after its been enabled would tough (if >> not impossible). Someone correct me if I am wrong here. >> >> Pratik. >> > I was thinking that an active swap partition was 'virtual memory'. > Why are many folks using capital letters 'VM'. Am I missing > something? Is 'VM' == virtual memory or is there a application > or service called 'VM' ? > > Anywho, the only 'virtual memory' I know of is an active > swap file or swap partition and either can be started > or stopped in a running kernel. > (I think.) > > Regards, Chuck From "Understanding the Linux Kernel": "Virtual memory acts as a logical layer between the application memory requests and the hardware Memory Management Unit (MMU)." It is an abstraction of system memory to provide an architecture-independent memory interface. It allows for a great many things, including swap functionality, but its primary function is to make the details of memory management invisible to application programmers. You just malloc() some memory, and you don't have to worry overmuch about far jumps, hardware cache alignment, or other annoying stuff. It also allows large malloc() calls to succeed, even if physical memory is completely fragmented, by maintaining a set of page tables that allow virtual-to-physical mapping of memory addresses. This is one of the most challenging areas of kernel development, and very hardware-specific. I tried to understand how it worked recently, gave myself a splitting headache after 30 minutes, and decided to let it sit for another year or so until I understand kernel internals, computer architecture, and assembler much better than I do now :) Jim - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
* Re: VM Vs Swap space 2004-10-07 22:13 ` chuck gelm 2004-10-08 2:49 ` Jim Nelson @ 2004-10-08 15:25 ` Pratik Solanki 1 sibling, 0 replies; 17+ messages in thread From: Pratik Solanki @ 2004-10-08 15:25 UTC (permalink / raw) To: chuck; +Cc: Ankit Jain, linux-newbie On Thu, 07 Oct 2004 18:13:52 -0400, chuck gelm <chuck@gelm.net> wrote: > Pratik Solanki wrote: > > >[CCing linux-newbie] > > > >On Thu, 7 Oct 2004 18:21:57 +0100 (BST), Ankit Jain > ><ankitjain1580@yahoo.com> wrote: > > > > > >>well i dont know exactly but somewhat i feel that > >>there must be some way to disable the virtual memory. > >>yaa of course there should be some way. it is not that > >>sys cant work without it > >> > >> > > > >Yes, you can have a system without virtual memory. Search for MMUless > >linux kernel and you'll see patches/websites. > > > >My point was that disabling VM after its been enabled would tough (if > >not impossible). Someone correct me if I am wrong here. > > > >Pratik. > > > I was thinking that an active swap partition was 'virtual memory'. > Why are many folks using capital letters 'VM'. Am I missing > something? Is 'VM' == virtual memory or is there a application > or service called 'VM' ? Yes, VM is virtual memory. > Anywho, the only 'virtual memory' I know of is an active > swap file or swap partition and either can be started > or stopped in a running kernel. > (I think.) Swap can be started or stopped. Virtual memory cannot be started or stopped. Just because you stopped swap does not mean the kernel is not using virtual memory. The kernel always uses virtual memory (except if its MMUless) . Swap is used only when the kernel needs more memory than what's physically available. Pratik. - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs ^ permalink raw reply [flat|nested] 17+ messages in thread
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2004-10-07 16:13 ` VM Vs Swap space Pratik Solanki
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