Re: [AOLSERVER] linux 2.4 and threading causes panic?

2002-01-22 Thread Titus Brown

- Anyone here running AOLserver (or developing other threaded
- apps.) under Linux 2.4?  Specifically, I'm using 2.4.17.
-
- I've got a box with a 2.4.1 kernel running a lightly-used AOLserver; it's
- been up for about 60 days with no kernel panic.  The data point may not
- correlate to your situation, though, considering that it's a different
- kernel and probably a really different workload.

I'm running 2.4.12 on a machine with about six different moderately used
AOLserver processes running.  No problems; AOLserver uptime corresponds
to the machine's uptime, ~90 days...

--titus



Re: [AOLSERVER] linux 2.4 and threading causes panic?

2002-01-22 Thread Dossy

It seems people misunderstood my original question.  Let me respond
to those who responded, then at the BOTTOM of this email, better
elaborate on my original question.


On 2002.01.22, Peter M. Jansson [EMAIL PROTECTED] wrote:
 I've got a box with a 2.4.1 kernel running a lightly-used AOLserver; it's
 been up for about 60 days with no kernel panic.  The data point may not
 correlate to your situation, though, considering that it's a different
 kernel and probably a really different workload.

Does the nsd process uptime match the machine uptime?  If so, then
you wouldn't have seen the problem.

On 2002.01.22, Titus Brown [EMAIL PROTECTED] wrote:
 I'm running 2.4.12 on a machine with about six different moderately used
 AOLserver processes running.  No problems; AOLserver uptime corresponds
 to the machine's uptime, ~90 days...

You wouldn't see the problem, then.

On 2002.01.22, Jon Griffin [EMAIL PROTECTED] wrote:
 I am running multiple AOLservers on 2.4.17 hardened boxes and have no
 problems.

Doing any virtual hosting with nsvhr?

===

Okay, what I was asking was, is anyone doing _development_ of AOLserver
on Linux 2.4.x kernels.  Particularly, development where you've made
a small boo-boo and scribbled some memory, causing a segfault, due to
bad pointer use -- in my case, memcpy()'ing more data into a pointer
than was allocated.

Normally, this just causes a segfault, and the process gets cleaned up,
and you start over.  However, on my machine, it causes a segfault, and
kills and reaps the process, but somewhere between the segfault,
reaping the process, and slightly afterwards ... the machine kernel
panics.  No oops gets saved because it refuses to sync on this kernel
panic.  Plus, since I'm guessing that it's kernel memory that's getting
stomped on, the oops output may be erroneous anyway.

Does someone have a dev. box running x86 Linux 2.4.17 with libc6 2.2.4
where they'd be willing to run an experiment?  Inside a thread, just
do something like this:

char *foo;
char *bar;
int i;

foo = malloc(10);
bar = malloc(100);

for (i = 0; i  100; i++) bar[i] = i;

memcpy(foo, bar, 50);

That should segfault, but if it's inside a thread, memory protection
in the Linux kernel doesn't seem to stop the thread from hosing memory
it's not allowed to touch.  That's my guess as to why my box keeps
panicking, at least.

Maybe someone like Rob could speak up about this, since he seems to
be very knowledgeable about these sorts of things.

-- Dossy

--
Dossy Shiobara   mail: [EMAIL PROTECTED]
Panoptic Computer Network web: http://www.panoptic.com/
  He realized the fastest way to change is to laugh at your own
folly -- then you can let go and quickly move on. (p. 70)



Re: [AOLSERVER] linux 2.4 and threading causes panic?

2002-01-22 Thread Lamar Owen

On Tuesday 22 January 2002 02:20 pm, Dossy wrote:
 That should segfault, but if it's inside a thread, memory protection
 in the Linux kernel doesn't seem to stop the thread from hosing memory
 it's not allowed to touch.  That's my guess as to why my box keeps
 panicking, at least.

Trying to stave off the obvious here:  you have at least twice as much swap
as physical RAM, right?  The 2.4.x kernel can die a horrible screaming death
if swap isn't larger than twice RAM -- under many conditions, segfaulting
being one of them.
--
Lamar Owen
WGCR Internet Radio
1 Peter 4:11