• Jason A. Harmening's avatar
    amd64 pmap: convert to counter(9), add PV and pagetable page counts · e4b8deb2
    Jason A. Harmening authored
    This change converts most of the counters in the amd64 pmap from
    global atomics to scalable counter(9) counters.  Per discussion
    with kib@, it also removes the handrolled per-CPU PCID save count
    as it isn't considered generally useful.
    The bulk of these counters remain guarded by PV_STATS, as it seems
    unlikely that they will be useful outside of very specific debugging
    scenarios.  However, this change does add two new counters that
    are available without PV_STATS.  pt_page_count and pv_page_count
    track the number of active physical-to-virtual list pages and page
    table pages, respectively.  These will be useful in evaluating
    the memory footprint of pmap structures under various workloads,
    which will help to guide future changes in this area.
    Reviewed by:	kib
    Differential Revision:	https://reviews.freebsd.org/D28923