Hello Michal! ----- Original Message ----- > From: "Michal Hocko" <mhocko@xxxxxxxxxx> > To: "Rodrigo Freire" <rfreire@xxxxxxxxxx> > Cc: linux-mm@xxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx > Sent: Monday, July 2, 2018 8:29:06 AM > Subject: Re: [PATCH] mm: be more informative in OOM task list > > On Mon 02-07-18 07:22:13, Rodrigo Freire wrote: > > Hello Michal, > > > > ----- Original Message ----- > > > From: "Michal Hocko" <mhocko@xxxxxxxxxx> > > > To: "Rodrigo Freire" <rfreire@xxxxxxxxxx> > > > Cc: linux-mm@xxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx > > > Sent: Monday, July 2, 2018 6:30:43 AM > > > Subject: Re: [PATCH] mm: be more informative in OOM task list > > > > > > On Sun 01-07-18 13:09:40, Rodrigo Freire wrote: > > > > The default page memory unit of OOM task dump events might not be > > > > intuitive for the non-initiated when debugging OOM events. Add > > > > a small printk prior to the task dump informing that the memory > > > > units are actually memory _pages_. > > > > > > Does this really help? I understand the the oom report might be not the > > > easiest thing to grasp but wouldn't it be much better to actually add > > > documentation with clarification of each part of it? > > > > That would be great: After a quick grep -ri for oom in Documentation, > > I found several other files containing its own OOM behaviour modifier > > configurations. But it indeed lacks a central and canonical Doc file > > which documents the OOM Killer behavior and workflows. > > > > However, I still stand by my proposed patch: It is unobtrusive, infers > > no performance issue and clarifying: I recently worked in a case (for > > full disclosure: I am a far cry from a MM expert) where the sum of the > > RSS pages made sense when interpreted as real kB pages. Reason: There > > were processes sharing (a good amount of) memory regions, misleading > > the interpretation and that misled not only me, but some other > > colleagues a well: The pages was only sorted out after actually > > inspecting the source code. > > > > This patch is user-friendly and can be a great time saver to others in > > the community. > > Well, all other counters we print are in page units unless explicitly > kB. Your statement is correct. And I thought about that too. And then the doubt: * Maybe someone forgot to state that these values are in kB? > So I am not sure we really need to do anything but document the > output better. Maybe others will find it more important though. The thing is, it also led some other colleagues (a few!) to think the very same as me: That raised the flag and made me write the patch: That was indeed misleading. And you may not have a MM and OOM-versed specialist available all the time! ;-) Still ask you to reconsider. My best regards, - RF.
