On Thu, 23 Aug 2001, Federico Sevilla III wrote:
..
> o I now have 15 instances (is this the right term?) of soffice.bin every
> one of them with the same memory and CPU usages, using supposedly only
> 52MB for the entire lot.
Those are threads. Threading on Linux is implemented using the clone()
system call, which is a superset of fork(). Since threads share the same
memory space, the VSZ (virtual size) and RSS (resident size) columns will
be IDENTICAL.
..
> > o Opera (opera-static) has two, again with identical CPU and memory
> usages, so I deduce that again these are threads, and only use 20MB
> for the pair.
You deduce correctly. Most modern UI's use threads (Mozilla has five).
..
> o Apache-SSL (apache-ssl), though, has a bunch of processes running with
> different CPU and memory usages. Is it correct to deduce that the
> memory of these must be summed up to find out how much RAM apache-ssl
> in its entirety is using?
No. Total the RSS, this will give you the total resident size of all the
processes. But these processes also have common memory areas (for example,
every program needs libc.so.6 but for 20 apache processes, they're all
sharing a single copy of libc.so.6). So the answer is, It Depends. =)
p.s. subtracting the RSS from the VSZ should give you the shared memory
size (on a system which is not swapping yet). But for example, I'm using
StarOffice right now, my VSZ is 348MB!!! but my RSS is 65MB. I think it's
my X server causing that frightful bloat (multiple mmap()'s of the video
memory, most likely). So in this case VSZ - RSS will NOT give the shared
library memory.
--
Orlando Andico <[EMAIL PROTECTED]>
Mosaic Communications, Inc.
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