On Thu, Nov 02, 2023 at 10:24:04AM -0400, Pasha Tatashin wrote: > On Thu, Nov 2, 2023 at 1:42 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Wed, Nov 01, 2023 at 04:08:16PM -0700, Sourav Panda wrote: > > > Adds a new per-node PageMetadata field to > > > /sys/devices/system/node/nodeN/meminfo > > > > No, this file is already an abuse of sysfs and we need to get rid of it > > (it has multiple values in one file.) Please do not add to the > > nightmare by adding new values. > > Hi Greg, > > Today, nodeN/meminfo is a counterpart of /proc/meminfo, they contain > almost identical fields, but show node-wide and system-wide views. And that is wrong, and again, an abuse of sysfs, please do not continue to add to it, that will only cause problems. > Since per-page metadata is added into /proc/meminfo, it is logical to > add into nodeN/meminfo, some nodes can have more or less struct page > data based on size of the node, and also the way memory is configured, > such as use of vmemamp optimization etc, therefore this information is > useful to users. > > I am not aware of any example of where a system-wide field from > /proc/meminfo is represented as a separate sysfs file under node0/. If > nodeN/meminfo is ever broken down into separate files it will affect > all the fields in it the same way with or without per-page metadata All of the fields should be individual files, please start adding them if you want to add new items, I do not want to see additional abuse here as that will cause problems (as you are seeing with the proc file.) > > Also, even if you did want to do this, you didn't document it properly > > in Documentation/ABI/ :( > > The documentation for the fields in nodeN/meminfo is only specified > in Documentation/filesystems/proc.rst, there is no separate sysfs > Documentation for the fields in this file, we could certainly add > that. All sysfs files need to be documented in Documentation/ABI/ otherwise you should get a warning when running our testing scripts. thanks, greg k-h
