Messages in this thread | | | Date | Wed, 5 Jan 2022 09:58:36 -0300 | Subject | Re: Occasional hung with UM after enable VMAP_STACK | From | Walter Lozano <> |
| |
Hi Johannes,
On 1/4/22 16:49, Johannes Berg wrote: > On Tue, 2022-01-04 at 16:26 -0300, Walter Lozano wrote: >> Thank you for your quick response. The Debian configuration on package >> user-mode-linux have these settings >> >> CONFIG_HAVE_ARCH_VMAP_STACK=y >> CONFIG_VMAP_STACK=y > OK, so it actually _is_ enabled. > >> as you can see in [1]. I did run some tests disabling those settings, >> which passed without any hung. >> >> Unfortunately the "occasional" behavior makes this issue a bit tricky to >> debug. >> > Right. > > Hm. I've been running our tests with it for about three months and > haven't observed any hangs, but I guess that doesn't mean much.
The issue is very rare at least in my setup, I had to prepare a test environment to stress the system in order to be able to reproduce it more or less consistently. I will continue investigating and share any useful information.
> To be honest, I have no particular reason to even want it, other than > that it catches accidental DMA from stack more easily ... so I guess if > we can't find anything, we might as well revert it.
I hope we will be able to find the root cause of the issue.
> Feels like it _should_ work though, since it's just a different location > for the stack.
I see. Thank you again for your quick reply, I will keep you updated.
Regards,
Walter
-- Walter Lozano Collabora Ltd.
| |