sys/uvm/uvm_anon.c

30  * uvm_anon.c: uvm anon ops
54  * uvm_analloc: allocate a new anon.
56  * => anon will have no lock associated.
61 	struct vm_anon *anon;
63 	anon = pool_get(&uvm_anon_pool, PR_NOWAIT);
64 	if (anon) {
65 		anon->an_lock = NULL;
66 		anon->an_ref = 1;
67 		anon->an_page = NULL;
68 		anon->an_swslot = 0;
70 	return anon;
74  * uvm_anfree_list: free a single anon structure
76  * => anon must be removed from the amap (if anon was in an amap).
77  * => amap must be locked, if anon was owned by amap.
81 uvm_anfree_list(struct vm_anon *anon, struct pglist *pgl)
83 	struct vm_page *pg = anon->an_page;
85 	KASSERT(anon->an_lock == NULL || rw_write_held(anon->an_lock));
86 	KASSERT(anon->an_ref == 0);
92 		KASSERT(anon->an_lock != NULL);
100 			rw_obj_hold(anon->an_lock);
119 		if (anon->an_swslot != 0 && anon->an_swslot != SWSLOT_BAD) {
125 	anon->an_lock = NULL;
130 	uvm_anon_dropswap(anon);
132 	KASSERT(anon->an_page == NULL);
133 	KASSERT(anon->an_swslot == 0);
135 	pool_put(&uvm_anon_pool, anon);
139  * uvm_anwait: wait for memory to become available to allocate an anon.
144 	struct vm_anon *anon;
147 	anon = pool_get(&uvm_anon_pool, PR_WAITOK);
148 	pool_put(&uvm_anon_pool, anon);
152  * uvm_anon_pagein: fetch an anon's page.
154  * => anon must be locked, and is unlocked upon return.
159 uvm_anon_pagein(struct vm_amap *amap, struct vm_anon *anon)
164 	KASSERT(rw_write_held(anon->an_lock));
165 	KASSERT(anon->an_lock == amap->am_lock);
168 	 * Get the page of the anon.
170 	rv = uvmfault_anonget(NULL, amap, anon);
174 		KASSERT(rw_write_held(anon->an_lock));
182 		 * VM_PAGER_REFAULT  means that the anon was freed.
198 	pg = anon->an_page;
199 	if (anon->an_swslot > 0) {
200 		uvm_swap_free(anon->an_swslot, 1);
202 	anon->an_swslot = 0;
213 	rw_exit(anon->an_lock);
219  * uvm_anon_dropswap: release any swap resources from this anon.
221  * => anon must be locked or have a reference count of 0.
224 uvm_anon_dropswap(struct vm_anon *anon)
226 	KASSERT(anon->an_ref == 0 || rw_lock_held(anon->an_lock));
228 	if (anon->an_swslot == 0)
231 	uvm_swap_free(anon->an_swslot, 1);
232 	anon->an_swslot = 0;
237  * uvm_anon_release: release an anon and its page.
239  * => anon should not have any references.
240  * => anon must be locked.
244 uvm_anon_release(struct vm_anon *anon)
246 	struct vm_page *pg = anon->an_page;
249 	KASSERT(rw_write_held(anon->an_lock));
254 	KASSERT(pg->uanon == anon);
255 	KASSERT(anon->an_ref == 0);
261 	KASSERT(anon->an_page == NULL);
262 	lock = anon->an_lock;
263 	uvm_anon_dropswap(anon);
264 	pool_put(&uvm_anon_pool, anon);