On a system with 4GB of memory, and without the user space patch that spilts user space
just a stock kernel, I am seeing memory allocation failures with X server and simple
apps on a machine with a Pentium 4 processor and 500MB of memory.
If you load large apps and do a lot of skb traffic, the mempool abd slab caches start gobbling up pages
and don't seem to balance them very well, resulting in memory allocation failures over time if
the system stays up for a week or more.
I am also seeing the same behavior on another system which has been
running for almost 30 days with an skb based traffic regeneration test calling and sending skb's
in kernel between two interfaces.
The pages over time get stuck in the slab allocator and user
space apps start to fail on alloc
requests.
Rebooting the system clears
the problem, which slowly over time
comes back. I am seeing this with
stock kernels from kernel.org and on kernels I have patched,
so the problem seems to be
in the base code. I have spent
the last two weeks observing the problem to verify I can
reproduce it and it keeps happening.
Jeff