On Wed, May 28, 2025 at 07:57:26AM +0200, Holger Hoffstätte wrote: > I have been running with v2 on 6.15.0 without any issues so far, but just > found this in my server's kern.log: Thanks for testing! > It seems the condition (!n) in __ep_remove is not always true and the WARN_ON triggers. > This is the first and only time I've seen this. Currently rebuilding with v3. Yeah this means __ep_remove() thinks the item is in epoll's rdllist and attempt to remove it, but then couldn't actually find the item in the list. __ep_remove() relies on the 'ready' flag, and this flags is quite complicated. And as my colleague pointed out off-list, I got memory ordering wrong for this flag. Therefore it is likely that you stepped on a bug with this flag. I got rid of this flag in v3, so hopefully the problem goes away. Best regards, Nam
