Re: [PATCH] mm/slab: Increase width of first /proc/slabinfo column

Tobin C. Harding
2019-02-04T01:35:58Z

On Thu, Jan 31, 2019 at 06:43:10PM -0800, Matthew Wilcox wrote:
> On Fri, Feb 01, 2019 at 11:42:42AM +1100, Tobin C. Harding wrote:
> > Currently when displaying /proc/slabinfo if any cache names are too long
> > then the output columns are not aligned. We could do something fancy to
> > get the maximum length of any cache name in the system or we could just
> > increase the hardcoded width. Currently it is 17 characters. Monitors
> > are wide these days so lets just increase it to 30 characters.
>
> I had a proposal some time ago to turn the slab name from being kmalloced
> to being an inline 16 bytes (with some fun hacks for cgroups). I think
> that's a better approach than permitting such long names. For example,
> ext4_allocation_context could be shortened to ext4_alloc_ctx without
> losing any expressivity.
>
> Let me know if you can't find that and I'll try to dig it up.

Hi Willy,

I haven't managed to find the patch, I grep'ed LKML using a bunch of
search terms via the google group linux.kernel. Then I tried a bunch of
different search strings in google prefixed with `site:kernel.org`. All
to no avail.

I have an idea how to fix it without making life less convenient for
developers *or* for users, I know we don't discuss changes without a
patch so I'll hack it up.

I'm sure your solution contains things I don't understand yet (read: the
cgroups bit) so I'd love to bring your patch back to life but am happy
to work on another solution as well in the name of education.

thanks,
Tobin.