Re: mm: remove vmalloc info from /proc/meminfo

[Dave Jones <dsj@fb.com>]

On Mon, Nov 02, 2015 at 11:29:15AM -0800, Linus Torvalds wrote:
 > On Mon, Nov 2, 2015 at 10:36 AM, Dave Jones <dsj@fb.com> wrote:
 > > Reading /proc/meminfo is really slow, as it requires recomputing the
 > > vmalloc data every time, which is a lot of work, when most (all?)
 > > consumers of meminfo don't even care about those statistics.
 > 
 > Ahh. My version of this patch (which I actually committed yesterday,
 > since I remembered - will wonders never cease?) leaves the fields
 > around in the /proc/meminfo file, but just makes the values be zero.
 > It also removes the actual function to compute the data that nobody
 > uses any more.
 > 
 > I agree that we can eventually look at even removing the fields
 > entirely, but that's much more likely to break things. I can imagine
 > system tools that just root around for values, and break and complain
 > when they don't exist, even if all they do is report them (rather than
 > actually *use* them for anythign).
 > 
 > I guess I should just push out my tree. I didn't want to keep people
 > from testing plain 4.3, so I didn't push out yesterday.
 > 
 > Can you test what is now (where "now" means "it might take a minute or
 > two to mirror out") in my git repo?

That looks like it'll do the job just as well yeah, and I suppose is
a touch more conservative than my "burn it all down" approach.

	Dave