On (10/09/19 16:26), Michal Hocko wrote: > On Wed 09-10-19 15:56:32, Peter Oberparleiter wrote: > [...] > > A generic solution would be preferable from my point of view though, > > because otherwise each console driver owner would need to ensure that any > > lock taken in their console.write implementation is never held while > > memory is allocated/released. > > Considering that console.write is called from essentially arbitrary code > path IIUC then all the locks used in this path should be pretty much > tail locks or console internal ones without external dependencies. That's a good expectation, but I guess it's not always the case. One example might be NET console - net subsystem locks, net device drivers locks, maybe even some MM locks (skb allocations?). But even more "commonly used" consoles sometimes break that expectation. E.g. 8250 serial8250_console_write() serial8250_modem_status() wake_up_interruptible() And so on. -ss
