Author: alc Date: Sat Jun 22 16:26:38 2019 New Revision: 349290 URL: https://svnweb.freebsd.org/changeset/base/349290
Log: Introduce pmap_remove_l3_range() and use it in two places: (1) pmap_remove(), where it eliminates redundant TLB invalidations by pmap_remove() and pmap_remove_l3(), and (2) pmap_enter_l2(), where it may optimize the TLB invalidations by batching them. Reviewed by: markj MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12725 Modified: head/sys/arm64/arm64/pmap.c Modified: head/sys/arm64/arm64/pmap.c ============================================================================== --- head/sys/arm64/arm64/pmap.c Sat Jun 22 15:39:34 2019 (r349289) +++ head/sys/arm64/arm64/pmap.c Sat Jun 22 16:26:38 2019 (r349290) @@ -2510,6 +2510,82 @@ pmap_remove_l3(pmap_t pmap, pt_entry_t *l3, vm_offset_ } /* + * Remove the specified range of addresses from the L3 page table that is + * identified by the given L2 entry. + */ +static void +pmap_remove_l3_range(pmap_t pmap, pd_entry_t l2e, vm_offset_t sva, + vm_offset_t eva, struct spglist *free, struct rwlock **lockp) +{ + struct md_page *pvh; + struct rwlock *new_lock; + pt_entry_t *l3, old_l3; + vm_offset_t va; + vm_page_t m; + + PMAP_LOCK_ASSERT(pmap, MA_OWNED); + KASSERT(rounddown2(sva, L2_SIZE) + L2_SIZE == roundup2(eva, L2_SIZE), + ("pmap_remove_l3_range: range crosses an L3 page table boundary")); + va = eva; + for (l3 = pmap_l2_to_l3(&l2e, sva); sva != eva; l3++, sva += L3_SIZE) { + if (!pmap_l3_valid(pmap_load(l3))) { + if (va != eva) { + pmap_invalidate_range(pmap, va, sva); + va = eva; + } + continue; + } + old_l3 = pmap_load_clear(l3); + if ((old_l3 & ATTR_SW_WIRED) != 0) + pmap->pm_stats.wired_count--; + pmap_resident_count_dec(pmap, 1); + if ((old_l3 & ATTR_SW_MANAGED) != 0) { + m = PHYS_TO_VM_PAGE(old_l3 & ~ATTR_MASK); + if (pmap_page_dirty(old_l3)) + vm_page_dirty(m); + if ((old_l3 & ATTR_AF) != 0) + vm_page_aflag_set(m, PGA_REFERENCED); + new_lock = PHYS_TO_PV_LIST_LOCK(VM_PAGE_TO_PHYS(m)); + if (new_lock != *lockp) { + if (*lockp != NULL) { + /* + * Pending TLB invalidations must be + * performed before the PV list lock is + * released. Otherwise, a concurrent + * pmap_remove_all() on a physical page + * could return while a stale TLB entry + * still provides access to that page. + */ + if (va != eva) { + pmap_invalidate_range(pmap, va, + sva); + va = eva; + } + rw_wunlock(*lockp); + } + *lockp = new_lock; + rw_wlock(*lockp); + } + pmap_pvh_free(&m->md, pmap, sva); + if (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)) + vm_page_aflag_clear(m, PGA_WRITEABLE); + } + } + if (va == eva) + va = sva; + if (pmap_unuse_pt(pmap, sva, l2e, free)) { + sva += L3_SIZE; + break; + } + } + if (va != eva) + pmap_invalidate_range(pmap, va, sva); +} + +/* * Remove the given range of addresses from the specified map. * * It is assumed that the start and end are properly @@ -2519,9 +2595,9 @@ void pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { struct rwlock *lock; - vm_offset_t va, va_next; + vm_offset_t va_next; pd_entry_t *l0, *l1, *l2; - pt_entry_t l3_paddr, *l3; + pt_entry_t l3_paddr; struct spglist free; /* @@ -2594,28 +2670,8 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t if (va_next > eva) va_next = eva; - va = va_next; - for (l3 = pmap_l2_to_l3(l2, sva); sva != va_next; l3++, - sva += L3_SIZE) { - if (l3 == NULL) - panic("l3 == NULL"); - if (pmap_load(l3) == 0) { - if (va != va_next) { - pmap_invalidate_range(pmap, va, sva); - va = va_next; - } - continue; - } - if (va == va_next) - va = sva; - if (pmap_remove_l3(pmap, l3, sva, l3_paddr, &free, - &lock)) { - sva += L3_SIZE; - break; - } - } - if (va != va_next) - pmap_invalidate_range(pmap, va, sva); + pmap_remove_l3_range(pmap, l3_paddr, sva, va_next, &free, + &lock); } if (lock != NULL) rw_wunlock(lock); @@ -3419,8 +3475,7 @@ pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t vm_page_t m, struct rwlock **lockp) { struct spglist free; - pd_entry_t *l2, *l3, old_l2; - vm_offset_t sva; + pd_entry_t *l2, old_l2; vm_page_t l2pg, mt; PMAP_LOCK_ASSERT(pmap, MA_OWNED); @@ -3449,13 +3504,8 @@ pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t (void)pmap_remove_l2(pmap, l2, va, pmap_load(pmap_l1(pmap, va)), &free, lockp); else - for (sva = va; sva < va + L2_SIZE; sva += PAGE_SIZE) { - l3 = pmap_l2_to_l3(l2, sva); - if (pmap_l3_valid(pmap_load(l3)) && - pmap_remove_l3(pmap, l3, sva, old_l2, &free, - lockp) != 0) - break; - } + pmap_remove_l3_range(pmap, old_l2, va, va + L2_SIZE, + &free, lockp); vm_page_free_pages_toq(&free, true); if (va >= VM_MAXUSER_ADDRESS) { /* _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
