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()?