Messages in this thread | | | Date | Wed, 10 Jan 2018 13:41:57 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup |
| |
On Wed, 10 Jan 2018 10:12:52 -0800 Tejun Heo <tj@kernel.org> wrote:
> Hello, Steven. > > So, everything else on your message, sure. You do what you have to > do, but I really don't understand the following part, and this has > been the main source of frustration in the whole discussion. > > On Wed, Jan 10, 2018 at 01:05:17PM -0500, Steven Rostedt wrote: > > You on the other hand are showing unrealistic scenarios, and crying > > that it's what you see in production, with no proof of it. > > I've explained the same scenario multiple times. Unless you're > assuming that I'm lying, it should be amply clear that the scenario is > unrealistic - we've been seeing them taking place repeatedly for quite > a while.
The one scenario you did show was the recursive OOM messages, and as Peter Zijlstra pointed out that's more of a bug in the net console than a printk bug.
> > What I don't understand is why we can't address this seemingly obvious > problem. If there are technical reasons and the consensus is to not > solve this within flushing logic, sure, we can deal with it otherwise, > but we at least have to be able to agree that there are actual issues > here, no?
The issue with the solution you want to do with printk is that it can break existing printk usages. As Petr said, people want printk to do two things. 1 - print out data ASAP, 2 - not lock up the system. The two are fighting each other. You care more about 2 where I (and others, like Peter Zijlstra and Linus) care more about 1.
My solution can help with 2 without doing anything to hurt 1.
You are NACKing my solution because it doesn't solve this bug with net console. I believe net console should be fixed. You believe that printk should have a work around to not let net console type bugs occur. Which to me is papering over the real bugs.
-- Steve
| |