jb@koko.UUCP (John Birchfield) (03/15/89)
How much swap space is provided as a default on the PC7300 (3b1)? I have a 3b1 with 2 megs of memory (around 1.7 meg available) and a 67 meg hard disk. I wrote a program to allocate memory until it failed and it managed to suck up around 2.3 megs before malloc failed. It seems to me I should be able to do a little better than that. Any help would be greatly appreciated. I can't seem to find any documentation on the swap device. Thanks in advance...
mvadh@cbnews.ATT.COM (andrew.d.hay) (03/16/89)
In article <914@koko.UUCP> jb@koko.UUCP (John Birchfield) writes:
"How much swap space is provided as a default on the PC7300 (3b1)?
[]
"Any help would be greatly appreciated. I can't seem to find any
"documentation on the swap device.
"Thanks in advance...
try
iv -tv /dev/rfp000
partition 1 is the swap partition; the usual sizes are 4000 blocks for
single-user selection and 5000 blocks for multi-user.
you can make it any size you want. we have a machine here with an
8000 block swap space. it didn't seem to improve anything...
--
Andrew Hay +------------------------------------------------------+
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mvuxq.att.com!adh +------------------------------------------------------+alex@otter.UMBC.EDU (alex) (03/17/89)
In article <914@koko.UUCP>, jb@koko.UUCP (John Birchfield) writes: > How much swap space is provided as a default on the PC7300 (3b1)? > I have a 3b1 with 2 megs of memory (around 1.7 meg available) and > a 67 meg hard disk. I wrote a program to allocate memory until it > failed and it managed to suck up around 2.3 megs before malloc failed. > It seems to me I should be able to do a little better than that. Well, no actually. The 2.3 megs is limited by the process memory map, which only knows about the (virtual) addresses between 0x80000 and 0x300000. processes live in virtual memory, which is mapped like this: 0 -> 80000 Kernal 80000 -> 300000 Process user space 300000 -> 380000 Shared library space 380000 -> 400000 Dynamic Kernal space All processes live in a world like the one above, and the kernal keeps the worlds from conflicting. Although a process doesn't have to use all of the space allocated to it (unused pages don't exist, sortof.), Multiple copies of the VM map exist, and thats what the swap spacve is for. Malloc stops at 2.3 meg because the user world reserves 100K or so for stack space. (2ef000 comes to mind as an upper limit, but I'm not sure) :alex Alex Crain Systems Programmer alex@umbc3.umbc.edu Univ Md Baltimore County nerwin!alex@umbc3.umbc.edu
ditto@cbmvax.UUCP (Michael "Ford" Ditto) (03/17/89)
In article <914@koko.UUCP> jb@koko.UUCP (John Birchfield) writes: >How much swap space is provided as a default on the PC7300 (3b1)? >I have a 3b1 with 2 megs of memory (around 1.7 meg available) and >a 67 meg hard disk. I wrote a program to allocate memory until it >failed and it managed to suck up around 2.3 megs before malloc failed. >It seems to me I should be able to do a little better than that. That 2.3 megs amount represents the address space limitation of the Unix PC - The total of text, data, and stack segments can not exceed 2.5Meg. This is because only addresses 0x80000 - 0x300000 are available for normal use. The shared library text and data areas are separate from and in addition to that 2.5M amount. Between your text segment and your stack, you probably have about 2.3 Meg of mallocable memory left, so your results seem quite reasonable. -- -=] Ford [=- "The number of Unix installations (In Real Life: Mike Ditto) has grown to 10, with more expected." ford@kenobi.commodore.com - The Unix Programmer's Manual, ...!sdcsvax!crash!kenobi!ford 2nd Edition, June, 1972. ditto@cbmvax.commodore.com
todd@ivucsb.UUCP (Todd Day) (03/19/89)
In article <4891@cbnews.ATT.COM> mvadh@cbnews.ATT.COM (andrew.d.hay) writes:
~iv -tv /dev/rfp000
I tried this and got:
Cylinder 167, Track 2, Sector 16, uses Track 2, Sector 16 as Alternate.
Cylinder 149, Track 4, Sector 16, uses Track 4, Sector 16 as Alternate.
Cylinder 306, Track 5, Sector 16, uses Track 5, Sector 16 as Alternate.
Cylinder 150, Track 6, Sector 16, uses Track 6, Sector 16 as Alternate.
Cylinder 696, Track 6, Sector 16, uses Track 6, Sector 16 as Alternate.
^^??? ^^???
What does this mean?
--
-Todd Day-
Internet: todd%ivucsb.UUCP@anise.acc.com
UUCP: {pyramid, ucbvax}!ucsbcsl!nessus!ivucsb!todd
Other: todd@ivucsb.UUCP may not work yet.richm@cbnewsm.ATT.COM (richard.a.miani) (05/22/89)
Hi, I have a 3b1 with a 40 meg drive and 2 meg of core . Does anyone know a way to reconfigure the disk in place so that the swap space is different ? On other UNIX's it is easy, but the 3b1 kernel "panic"s when I try. I don't want to have to back up the disk and then reformat it !!! I will summarize any results I get and post later. Please reply via email. Thanks in advance ... Rich ------- Rich Miani ram%lcuxlf@research.att.com AT&T Bell Laboratories ram@lcuxlf.att.com Liberty Corner, New Jersey arpa!lcuxlf!ram