The branch stable/13 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=077d3c4c467e5e27f88b8d70864000f3eb0dab3c
commit 077d3c4c467e5e27f88b8d70864000f3eb0dab3c Author: Konstantin Belousov <[email protected]> AuthorDate: 2021-10-20 20:30:34 +0000 Commit: Konstantin Belousov <[email protected]> CommitDate: 2021-11-04 00:56:39 +0000 amd64 pmap: adjust the empty pmap optimization in pmap_remove() (cherry picked from commit 0b3bc7288984c17da00d9f8c29f116d56bf44d35) --- sys/amd64/amd64/pmap.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index c759ff840a24..524b40ed2fee 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -6160,9 +6160,14 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) PG_V = pmap_valid_bit(pmap); /* + * If there are no resident pages besides the top level page + * table page(s), there is nothing to do. Kernel pmap always + * accounts whole preloaded area as resident, which makes its + * resident count > 2. * Perform an unsynchronized read. This is, however, safe. */ - if (pmap->pm_stats.resident_count == 0) + if (pmap->pm_stats.resident_count <= 1 + (pmap->pm_pmltopu != NULL ? + 1 : 0)) return; anyvalid = 0;
