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.
