Author: markj Date: Tue Dec 10 18:15:20 2019 New Revision: 355587 URL: https://svnweb.freebsd.org/changeset/base/355587
Log: Add a helper function to the swapout daemon's deactivation code. vm_swapout_object_deactivate_pages() is renamed to vm_swapout_object_deactivate(), and the loop body is moved into the new vm_swapout_object_deactivate_page(). This makes the code a bit easier to follow and is in preparation for some functional changes. Reviewed by: jeff, kib Sponsored by: Netflix, Intel Differential Revision: https://reviews.freebsd.org/D22651 Modified: head/sys/vm/vm_swapout.c Modified: head/sys/vm/vm_swapout.c ============================================================================== --- head/sys/vm/vm_swapout.c Tue Dec 10 18:14:50 2019 (r355586) +++ head/sys/vm/vm_swapout.c Tue Dec 10 18:15:20 2019 (r355587) @@ -165,13 +165,64 @@ static int last_swapin; static void swapclear(struct proc *); static int swapout(struct proc *); static void vm_swapout_map_deactivate_pages(vm_map_t, long); -static void vm_swapout_object_deactivate_pages(pmap_t, vm_object_t, long); +static void vm_swapout_object_deactivate(pmap_t, vm_object_t, long); static void swapout_procs(int action); static void vm_req_vmdaemon(int req); static void vm_thread_swapout(struct thread *td); +static void +vm_swapout_object_deactivate_page(pmap_t pmap, vm_page_t m, bool unmap) +{ + int act_delta; + + if (vm_page_tryxbusy(m) == 0) + return; + VM_CNT_INC(v_pdpages); + + /* + * The page may acquire a wiring after this check. + * The page daemon handles wired pages, so there is + * no harm done if a wiring appears while we are + * attempting to deactivate the page. + */ + if (vm_page_wired(m) || !pmap_page_exists_quick(pmap, m)) { + vm_page_xunbusy(m); + return; + } + act_delta = pmap_ts_referenced(m); + vm_page_lock(m); + if ((m->a.flags & PGA_REFERENCED) != 0) { + if (act_delta == 0) + act_delta = 1; + vm_page_aflag_clear(m, PGA_REFERENCED); + } + if (!vm_page_active(m) && act_delta != 0) { + vm_page_activate(m); + m->a.act_count += act_delta; + } else if (vm_page_active(m)) { + /* + * The page daemon does not requeue pages + * after modifying their activation count. + */ + if (act_delta == 0) { + m->a.act_count -= min(m->a.act_count, ACT_DECLINE); + if (unmap && m->a.act_count == 0) { + (void)vm_page_try_remove_all(m); + vm_page_deactivate(m); + } + } else { + vm_page_activate(m); + if (m->a.act_count < ACT_MAX - ACT_ADVANCE) + m->a.act_count += ACT_ADVANCE; + } + } else if (vm_page_inactive(m)) + (void)vm_page_try_remove_all(m); + vm_page_unlock(m); + vm_page_xunbusy(m); +} + /* - * vm_swapout_object_deactivate_pages + * vm_swapout_object_deactivate * * Deactivate enough pages to satisfy the inactive target * requirements. @@ -179,12 +230,12 @@ static void vm_thread_swapout(struct thread *td); * The object and map must be locked. */ static void -vm_swapout_object_deactivate_pages(pmap_t pmap, vm_object_t first_object, +vm_swapout_object_deactivate(pmap_t pmap, vm_object_t first_object, long desired) { vm_object_t backing_object, object; - vm_page_t p; - int act_delta, remove_mode; + vm_page_t m; + bool unmap; VM_OBJECT_ASSERT_LOCKED(first_object); if ((first_object->flags & OBJ_FICTITIOUS) != 0) @@ -197,63 +248,19 @@ vm_swapout_object_deactivate_pages(pmap_t pmap, vm_obj REFCOUNT_COUNT(object->paging_in_progress) > 0) goto unlock_return; - remove_mode = 0; + unmap = true; if (object->shadow_count > 1) - remove_mode = 1; + unmap = false; + /* * Scan the object's entire memory queue. */ - TAILQ_FOREACH(p, &object->memq, listq) { + TAILQ_FOREACH(m, &object->memq, listq) { if (pmap_resident_count(pmap) <= desired) goto unlock_return; if (should_yield()) goto unlock_return; - if (vm_page_tryxbusy(p) == 0) - continue; - VM_CNT_INC(v_pdpages); - - /* - * The page may acquire a wiring after this check. - * The page daemon handles wired pages, so there is - * no harm done if a wiring appears while we are - * attempting to deactivate the page. - */ - if (vm_page_wired(p) || !pmap_page_exists_quick(pmap, p)) { - vm_page_xunbusy(p); - continue; - } - act_delta = pmap_ts_referenced(p); - vm_page_lock(p); - if ((p->a.flags & PGA_REFERENCED) != 0) { - if (act_delta == 0) - act_delta = 1; - vm_page_aflag_clear(p, PGA_REFERENCED); - } - if (!vm_page_active(p) && act_delta != 0) { - vm_page_activate(p); - p->a.act_count += act_delta; - } else if (vm_page_active(p)) { - /* - * The page daemon does not requeue pages - * after modifying their activation count. - */ - if (act_delta == 0) { - p->a.act_count -= min(p->a.act_count, - ACT_DECLINE); - if (!remove_mode && p->a.act_count == 0) { - (void)vm_page_try_remove_all(p); - vm_page_deactivate(p); - } - } else { - vm_page_activate(p); - if (p->a.act_count < ACT_MAX - - ACT_ADVANCE) - p->a.act_count += ACT_ADVANCE; - } - } else if (vm_page_inactive(p)) - (void)vm_page_try_remove_all(p); - vm_page_unlock(p); - vm_page_xunbusy(p); + vm_swapout_object_deactivate_page(pmap, m, unmap); } if ((backing_object = object->backing_object) == NULL) goto unlock_return; @@ -307,7 +314,7 @@ vm_swapout_map_deactivate_pages(vm_map_t map, long des } if (bigobj != NULL) { - vm_swapout_object_deactivate_pages(map->pmap, bigobj, desired); + vm_swapout_object_deactivate(map->pmap, bigobj, desired); VM_OBJECT_RUNLOCK(bigobj); } /* @@ -321,8 +328,8 @@ vm_swapout_map_deactivate_pages(vm_map_t map, long des obj = tmpe->object.vm_object; if (obj != NULL) { VM_OBJECT_RLOCK(obj); - vm_swapout_object_deactivate_pages(map->pmap, - obj, desired); + vm_swapout_object_deactivate(map->pmap, obj, + desired); VM_OBJECT_RUNLOCK(obj); } } _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
