[9fans] memory limit for swapping?

[9fans] memory limit for swapping?

[okamoto]

Does swapping have any memory limit around 226MB?
This is caused from a bug of our program, however, it failes always
around swapping volume of 226MB.   Does it come from some limits
for swapping?  Or I'm just doing stupid?

Kenji

PS.  Sorry interrupting your vacation.  :-)

Re: [9fans] memory limit for swapping?

[okamoto]

Thank you very much, Russ.
Yes, I forgot the size of swap partition which I must have done long time
ago. ^_^

The openning message says:

19462 free pages
77848k bytes
311448k swap

According to your explanation, I'll have 233.6MB swap limits which
consistent with my observation.

Kenji

PS. Russ, when you take vacation?  Or programming is your rest?

Re: [9fans] memory limit for swapping?

[Russ Cox]

> Does swapping have any memory limit around 226MB?
> This is caused from a bug of our program, however, it failes always
> around swapping volume of 226MB.   Does it come from some limits
> for swapping?  Or I'm just doing stupid?

How big is your swap partition?  The system
does not fail gracefully once it gets full.

Also, there is a fixed limit on the swap size.  If you
follow through pc/main.c you can derive what the exact
limits on conf.nswap are.  I don't have the stomach, but
it's clear that it's proportional to the amount of memory in
the system but capped at a certain point.  The easiest
way to tell is to look at the message at boot: if it says

1000 free pages
10000K bytes
15000K swap

then the system swap space limit is 5MB (15000K-10000K).
The last number is actually physical user memory + swap space
(total user virtual memory) rather than swap space.
It would be more accurate to phrase it as

user memory: 1000 pages, 10M physical, 15M virtual

You might just be exhausting the virtual space.

Russ