Re: [PATCH] mm: don't show nr_indirectly_reclaimable in /proc/vmstat

From: Vlastimil Babka
Date: Mon Apr 30 2018 - 11:32:27 EST

On 04/27/2018 08:41 PM, David Rientjes wrote:
> On Fri, 27 Apr 2018, Vlastimil Babka wrote:
>> It was in the original thread, see e.g.
>> <08524819-14ef-81d0-fa90-d7af13c6b9d5@xxxxxxx>
>> However it will take some time to get that in mainline, and meanwhile
>> the current implementation does prevent a DOS. So I doubt it can be
>> fully reverted - as a compromise I just didn't want the counter to
>> become ABI. TBH though, other people at LSF/MM didn't seem concerned
>> that /proc/vmstat is an ABI that we can't change (i.e. counters have
>> been presumably removed in the past already).
> What prevents this from being a simple atomic_t that gets added to in
> __d_alloc(), subtracted from in __d_free_external_name(), and read in
> si_mem_available() and __vm_enough_memory()?

The counter is already in mainline, so I think it's easier to simply
just stop printing it now than trying to replace its implementation with
one that can cause cache ping pongs.