> On 25 Jun 2017, at 17:32, Ryan Stone <ryst...@gmail.com> wrote: > > Having looking at the original email more closely, I see that you showed an > mlxen interface with a 9020 MTU. Seeing allocation failures of 9k mbuf > clusters increase while you are far below the zone's limit means that you're > definitely running into the bug I'm describing, and this bug could plausibly > cause the iSCSI errors that you describe. > > The issue is that the newer version of the driver tries to allocate a single > buffer to accommodate an MTU-sized packet. Over time, however, memory will > become fragmented and eventually it can become impossible to allocate a 9k > physically contiguous buffer. When this happens the driver is unable to > allocate buffers to receive packets and is forced to drop them. Presumably, > if iSCSI suffers too many packet drops it will terminate the connection. The > older version of the driver limited itself to page-sized buffers, so it was > immune to issues with memory fragmentation.
Thank you for your explanation Ryan. You say "over time", and you're right, I have to wait several days (here 88) before the problem occurs. Strange however that in 2500MB free memory system is unable to find 9k physically contiguous. But we never know :) Let's then wait for your patch ! (and reboot for now) Many thx ! Ben _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
