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| author | alc <alc@FreeBSD.org> | 2012-06-11 21:41:16 +0000 |
|---|---|---|
| committer | alc <alc@FreeBSD.org> | 2012-06-11 21:41:16 +0000 |
| commit | fece26df6f404ac528422ccf427a99e286577eaf (patch) | |
| tree | 0143fe2ad61b368bf3afdbfcd8b2de1cd83398af /sys/amd64 | |
| parent | 6a1a47c355eb1428f5c14e63ee76b3eb5644813a (diff) | |
| download | FreeBSD-src-fece26df6f404ac528422ccf427a99e286577eaf.zip FreeBSD-src-fece26df6f404ac528422ccf427a99e286577eaf.tar.gz | |
Avoid unnecessary atomic operations for clearing PGA_WRITEABLE in
pmap_remove_pages(). This reduces pmap_remove_pages()'s running time by
4 to 11% in my tests.
MFC after: 1 week
Diffstat (limited to 'sys/amd64')
| -rw-r--r-- | sys/amd64/amd64/pmap.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index 35cb131..507c685 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -4197,7 +4197,8 @@ pmap_remove_pages(pmap_t pmap) TAILQ_REMOVE(&pvh->pv_list, pv, pv_list); if (TAILQ_EMPTY(&pvh->pv_list)) { for (mt = m; mt < &m[NBPDR / PAGE_SIZE]; mt++) - if (TAILQ_EMPTY(&mt->md.pv_list)) + if ((mt->aflags & PGA_WRITEABLE) != 0 && + TAILQ_EMPTY(&mt->md.pv_list)) vm_page_aflag_clear(mt, PGA_WRITEABLE); } mpte = pmap_lookup_pt_page(pmap, pv->pv_va); @@ -4213,7 +4214,8 @@ pmap_remove_pages(pmap_t pmap) } else { pmap_resident_count_dec(pmap, 1); TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); - if (TAILQ_EMPTY(&m->md.pv_list) && + if ((m->aflags & PGA_WRITEABLE) != 0 && + TAILQ_EMPTY(&m->md.pv_list) && (m->flags & PG_FICTITIOUS) == 0) { pvh = pa_to_pvh(VM_PAGE_TO_PHYS(m)); if (TAILQ_EMPTY(&pvh->pv_list)) |
