On Thu, Feb 15, 2024 at 08:22:44PM -0500, Pasha Tatashin wrote: > On Thu, Feb 15, 2024 at 8:00 PM Kent Overstreet > <kent.overstreet@xxxxxxxxx> wrote: > > > > On Thu, Feb 15, 2024 at 04:54:38PM -0800, Andrew Morton wrote: > > > On Mon, 12 Feb 2024 13:38:59 -0800 Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > > > > > > +Example output. > > > > + > > > > +:: > > > > + > > > > + > cat /proc/allocinfo > > > > + > > > > + 153MiB mm/slub.c:1826 module:slub func:alloc_slab_page > > > > + 6.08MiB mm/slab_common.c:950 module:slab_common func:_kmalloc_order > > > > + 5.09MiB mm/memcontrol.c:2814 module:memcontrol func:alloc_slab_obj_exts > > > > + 4.54MiB mm/page_alloc.c:5777 module:page_alloc func:alloc_pages_exact > > > > + 1.32MiB include/asm-generic/pgalloc.h:63 module:pgtable func:__pte_alloc_one > > > > > > I don't really like the fancy MiB stuff. Wouldn't it be better to just > > > present the amount of memory in plain old bytes, so people can use sort > > > -n on it? > > > > They can use sort -h on it; the string_get_size() patch was specifically > > so that we could make the output compatible with sort -h > > > > > And it's easier to tell big-from-small at a glance because > > > big has more digits. > > > > > > Also, the first thing any sort of downstream processing of this data is > > > going to have to do is to convert the fancified output back into > > > plain-old-bytes. So why not just emit plain-old-bytes? > > > > > > If someone wants the fancy output (and nobody does) then that can be > > > done in userspace. > > > > I like simpler, more discoverable tools; e.g. we've got a bunch of > > interesting stuff in scripts/ but it doesn't get used nearly as much - > > not as accessible as cat'ing a file, definitely not going to be > > installed by default. > > I also prefer plain bytes instead of MiB. A driver developer that > wants to verify up-to the byte allocations for a new data structure > that they added is going to be disappointed by the rounded MiB > numbers. That's a fair point. > The data contained in this file is not consumable without at least > "sort -h -r", so why not just output bytes instead? > > There is /proc/slabinfo and there is a slabtop tool. > For raw /proc/allocinfo we can create an alloctop tool that would > parse, sort and show data in human readable format based on various > criteria. > > We should also add at the top of this file "allocinfo - version: 1.0", > to allow future extensions (i.e. column for proc name). How would we feel about exposing two different versions in /proc? It should be a pretty minimal addition to .text. Personally, I hate trying to count long strings digits by eyeball...
