Hi Jann, On 10/12/20 4:52 PM, Jann Horn wrote: > On Mon, Oct 12, 2020 at 1:49 PM Jann Horn <jannh@xxxxxxxxxx> wrote: >> Since 34e55232e59f7b19050267a05ff1226e5cd122a5 (introduced back in >> v2.6.34), Linux uses per-thread RSS counters to reduce cache contention on >> the per-mm counters. With a 4K page size, that means that you can end up >> with the counters off by up to 252KiB per thread. > > Actually, as Mark Mossberg pointed out to me off-thread, the counters > can actually be off by many times more... So, does your patch to proc.5 need tweaking, or can I just apply as is? Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/