Dmitry Yusupov wrote:

On Tue, 2005-03-29 at 17:20 +0200, Andi Kleen wrote:

quoted

quoted

In your scenario, if we're out of memory and the system needs several
ACK's to the swap device for pages to be released to the system, I don't
see how we make forward progress since without a reserved resource to
allocate from how does the ack make it up the stack to the storage
driver layer?

Typically because the RX ring of the driver has some packets left.

You can not be sure. Some NICs has very small number for possible HW
ring buffers. Under OOM pressure, most likely, host will be so slow that
resources might not just be returned back to the HW in time. Though it
depends on link-layer driver implementation.

This seems to become part of the whole thing... in other words, in an 
OOM situation, may have to free RX ring entries by just dropping packets 
as necessary...

	-hpa