Hello, Peter. On Wed, Jan 24, 2018 at 10:36:07AM +0100, Peter Zijlstra wrote: > On Wed, Jan 10, 2018 at 09:02:23AM -0800, Tejun Heo wrote: > > 1. Console is IPMI emulated serial console. Super slow. Also > > netconsole is in use. > > So my IPMI SoE typically run at 115200 Baud (or higher) and I've not had > trouble like that (granted I don't typically trigger OOM storms, but > they do occasionally happen). > > Is your IPMI much slower and not fixable to be faster? It looks like the latest machines have the baud rate at 57600 and I'm pretty sure we have a lot of slower ones. 57600 isn't 9600 but is still slow enough to get into trouble often enough. There are a huge number of machines running all sorts of things under heavy load and trying to rapidly deploy new kernels / features contributes to encountering bugs and weird corner cases. UART can run a lot faster and I have no idea why IPMI consoles behave as if they were connected over mile-long DB9 cables. Maybe we can convince hardware people to improve it but, even if that happened today, we'd still be looking at years of dealing with slower ones, and IPMI situation here is likely better than what many others are facing. idk, it's not a particularly difficult problem to solve from kernel side. Just need to figure out a better / more robust trade-off. Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
