1 /* SPDX-License-Identifier: GPL-2.0
4 * Author: Jesper Dangaard Brouer <netoptimizer@brouer.com>
5 * Copyright (C) 2016 Red Hat, Inc.
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/device.h>
13 #include <net/page_pool.h>
16 #include <linux/dma-direction.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/page-flags.h>
19 #include <linux/mm.h> /* for __put_page() */
20 #include <linux/poison.h>
21 #include <linux/ethtool.h>
23 #include <trace/events/page_pool.h>
25 #define DEFER_TIME (msecs_to_jiffies(1000))
26 #define DEFER_WARN_INTERVAL (60 * HZ)
28 #define BIAS_MAX LONG_MAX
30 #ifdef CONFIG_PAGE_POOL_STATS
31 /* alloc_stat_inc is intended to be used in softirq context */
32 #define alloc_stat_inc(pool, __stat) (pool->alloc_stats.__stat++)
33 /* recycle_stat_inc is safe to use when preemption is possible. */
34 #define recycle_stat_inc(pool, __stat) \
36 struct page_pool_recycle_stats __percpu *s = pool->recycle_stats; \
37 this_cpu_inc(s->__stat); \
40 #define recycle_stat_add(pool, __stat, val) \
42 struct page_pool_recycle_stats __percpu *s = pool->recycle_stats; \
43 this_cpu_add(s->__stat, val); \
46 static const char pp_stats[][ETH_GSTRING_LEN] = {
49 "rx_pp_alloc_slow_ho",
53 "rx_pp_recycle_cached",
54 "rx_pp_recycle_cache_full",
56 "rx_pp_recycle_ring_full",
57 "rx_pp_recycle_released_ref",
60 bool page_pool_get_stats(struct page_pool *pool,
61 struct page_pool_stats *stats)
68 /* The caller is responsible to initialize stats. */
69 stats->alloc_stats.fast += pool->alloc_stats.fast;
70 stats->alloc_stats.slow += pool->alloc_stats.slow;
71 stats->alloc_stats.slow_high_order += pool->alloc_stats.slow_high_order;
72 stats->alloc_stats.empty += pool->alloc_stats.empty;
73 stats->alloc_stats.refill += pool->alloc_stats.refill;
74 stats->alloc_stats.waive += pool->alloc_stats.waive;
76 for_each_possible_cpu(cpu) {
77 const struct page_pool_recycle_stats *pcpu =
78 per_cpu_ptr(pool->recycle_stats, cpu);
80 stats->recycle_stats.cached += pcpu->cached;
81 stats->recycle_stats.cache_full += pcpu->cache_full;
82 stats->recycle_stats.ring += pcpu->ring;
83 stats->recycle_stats.ring_full += pcpu->ring_full;
84 stats->recycle_stats.released_refcnt += pcpu->released_refcnt;
89 EXPORT_SYMBOL(page_pool_get_stats);
91 u8 *page_pool_ethtool_stats_get_strings(u8 *data)
95 for (i = 0; i < ARRAY_SIZE(pp_stats); i++) {
96 memcpy(data, pp_stats[i], ETH_GSTRING_LEN);
97 data += ETH_GSTRING_LEN;
102 EXPORT_SYMBOL(page_pool_ethtool_stats_get_strings);
104 int page_pool_ethtool_stats_get_count(void)
106 return ARRAY_SIZE(pp_stats);
108 EXPORT_SYMBOL(page_pool_ethtool_stats_get_count);
110 u64 *page_pool_ethtool_stats_get(u64 *data, void *stats)
112 struct page_pool_stats *pool_stats = stats;
114 *data++ = pool_stats->alloc_stats.fast;
115 *data++ = pool_stats->alloc_stats.slow;
116 *data++ = pool_stats->alloc_stats.slow_high_order;
117 *data++ = pool_stats->alloc_stats.empty;
118 *data++ = pool_stats->alloc_stats.refill;
119 *data++ = pool_stats->alloc_stats.waive;
120 *data++ = pool_stats->recycle_stats.cached;
121 *data++ = pool_stats->recycle_stats.cache_full;
122 *data++ = pool_stats->recycle_stats.ring;
123 *data++ = pool_stats->recycle_stats.ring_full;
124 *data++ = pool_stats->recycle_stats.released_refcnt;
128 EXPORT_SYMBOL(page_pool_ethtool_stats_get);
131 #define alloc_stat_inc(pool, __stat)
132 #define recycle_stat_inc(pool, __stat)
133 #define recycle_stat_add(pool, __stat, val)
136 static int page_pool_init(struct page_pool *pool,
137 const struct page_pool_params *params)
139 unsigned int ring_qsize = 1024; /* Default */
141 memcpy(&pool->p, params, sizeof(pool->p));
143 /* Validate only known flags were used */
144 if (pool->p.flags & ~(PP_FLAG_ALL))
147 if (pool->p.pool_size)
148 ring_qsize = pool->p.pool_size;
150 /* Sanity limit mem that can be pinned down */
151 if (ring_qsize > 32768)
154 /* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL.
155 * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
156 * which is the XDP_TX use-case.
158 if (pool->p.flags & PP_FLAG_DMA_MAP) {
159 if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
160 (pool->p.dma_dir != DMA_BIDIRECTIONAL))
164 if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) {
165 /* In order to request DMA-sync-for-device the page
168 if (!(pool->p.flags & PP_FLAG_DMA_MAP))
171 if (!pool->p.max_len)
174 /* pool->p.offset has to be set according to the address
175 * offset used by the DMA engine to start copying rx data
179 if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT &&
180 pool->p.flags & PP_FLAG_PAGE_FRAG)
183 #ifdef CONFIG_PAGE_POOL_STATS
184 pool->recycle_stats = alloc_percpu(struct page_pool_recycle_stats);
185 if (!pool->recycle_stats)
189 if (ptr_ring_init(&pool->ring, ring_qsize, GFP_KERNEL) < 0)
192 atomic_set(&pool->pages_state_release_cnt, 0);
194 /* Driver calling page_pool_create() also call page_pool_destroy() */
195 refcount_set(&pool->user_cnt, 1);
197 if (pool->p.flags & PP_FLAG_DMA_MAP)
198 get_device(pool->p.dev);
203 struct page_pool *page_pool_create(const struct page_pool_params *params)
205 struct page_pool *pool;
208 pool = kzalloc_node(sizeof(*pool), GFP_KERNEL, params->nid);
210 return ERR_PTR(-ENOMEM);
212 err = page_pool_init(pool, params);
214 pr_warn("%s() gave up with errno %d\n", __func__, err);
221 EXPORT_SYMBOL(page_pool_create);
223 static void page_pool_return_page(struct page_pool *pool, struct page *page);
226 static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)
228 struct ptr_ring *r = &pool->ring;
230 int pref_nid; /* preferred NUMA node */
232 /* Quicker fallback, avoid locks when ring is empty */
233 if (__ptr_ring_empty(r)) {
234 alloc_stat_inc(pool, empty);
238 /* Softirq guarantee CPU and thus NUMA node is stable. This,
239 * assumes CPU refilling driver RX-ring will also run RX-NAPI.
242 pref_nid = (pool->p.nid == NUMA_NO_NODE) ? numa_mem_id() : pool->p.nid;
244 /* Ignore pool->p.nid setting if !CONFIG_NUMA, helps compiler */
245 pref_nid = numa_mem_id(); /* will be zero like page_to_nid() */
248 /* Refill alloc array, but only if NUMA match */
250 page = __ptr_ring_consume(r);
254 if (likely(page_to_nid(page) == pref_nid)) {
255 pool->alloc.cache[pool->alloc.count++] = page;
258 * (1) release 1 page to page-allocator and
259 * (2) break out to fallthrough to alloc_pages_node.
260 * This limit stress on page buddy alloactor.
262 page_pool_return_page(pool, page);
263 alloc_stat_inc(pool, waive);
267 } while (pool->alloc.count < PP_ALLOC_CACHE_REFILL);
269 /* Return last page */
270 if (likely(pool->alloc.count > 0)) {
271 page = pool->alloc.cache[--pool->alloc.count];
272 alloc_stat_inc(pool, refill);
279 static struct page *__page_pool_get_cached(struct page_pool *pool)
283 /* Caller MUST guarantee safe non-concurrent access, e.g. softirq */
284 if (likely(pool->alloc.count)) {
286 page = pool->alloc.cache[--pool->alloc.count];
287 alloc_stat_inc(pool, fast);
289 page = page_pool_refill_alloc_cache(pool);
295 static void page_pool_dma_sync_for_device(struct page_pool *pool,
297 unsigned int dma_sync_size)
299 dma_addr_t dma_addr = page_pool_get_dma_addr(page);
301 dma_sync_size = min(dma_sync_size, pool->p.max_len);
302 dma_sync_single_range_for_device(pool->p.dev, dma_addr,
303 pool->p.offset, dma_sync_size,
307 static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
311 /* Setup DMA mapping: use 'struct page' area for storing DMA-addr
312 * since dma_addr_t can be either 32 or 64 bits and does not always fit
313 * into page private data (i.e 32bit cpu with 64bit DMA caps)
314 * This mapping is kept for lifetime of page, until leaving pool.
316 dma = dma_map_page_attrs(pool->p.dev, page, 0,
317 (PAGE_SIZE << pool->p.order),
318 pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
319 if (dma_mapping_error(pool->p.dev, dma))
322 page_pool_set_dma_addr(page, dma);
324 if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
325 page_pool_dma_sync_for_device(pool, page, pool->p.max_len);
330 static void page_pool_set_pp_info(struct page_pool *pool,
334 page->pp_magic |= PP_SIGNATURE;
335 if (pool->p.init_callback)
336 pool->p.init_callback(page, pool->p.init_arg);
339 static void page_pool_clear_pp_info(struct page *page)
345 static struct page *__page_pool_alloc_page_order(struct page_pool *pool,
351 page = alloc_pages_node(pool->p.nid, gfp, pool->p.order);
355 if ((pool->p.flags & PP_FLAG_DMA_MAP) &&
356 unlikely(!page_pool_dma_map(pool, page))) {
361 alloc_stat_inc(pool, slow_high_order);
362 page_pool_set_pp_info(pool, page);
364 /* Track how many pages are held 'in-flight' */
365 pool->pages_state_hold_cnt++;
366 trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt);
372 static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
375 const int bulk = PP_ALLOC_CACHE_REFILL;
376 unsigned int pp_flags = pool->p.flags;
377 unsigned int pp_order = pool->p.order;
381 /* Don't support bulk alloc for high-order pages */
382 if (unlikely(pp_order))
383 return __page_pool_alloc_page_order(pool, gfp);
385 /* Unnecessary as alloc cache is empty, but guarantees zero count */
386 if (unlikely(pool->alloc.count > 0))
387 return pool->alloc.cache[--pool->alloc.count];
389 /* Mark empty alloc.cache slots "empty" for alloc_pages_bulk_array */
390 memset(&pool->alloc.cache, 0, sizeof(void *) * bulk);
392 nr_pages = alloc_pages_bulk_array(gfp, bulk, pool->alloc.cache);
393 if (unlikely(!nr_pages))
396 /* Pages have been filled into alloc.cache array, but count is zero and
397 * page element have not been (possibly) DMA mapped.
399 for (i = 0; i < nr_pages; i++) {
400 page = pool->alloc.cache[i];
401 if ((pp_flags & PP_FLAG_DMA_MAP) &&
402 unlikely(!page_pool_dma_map(pool, page))) {
407 page_pool_set_pp_info(pool, page);
408 pool->alloc.cache[pool->alloc.count++] = page;
409 /* Track how many pages are held 'in-flight' */
410 pool->pages_state_hold_cnt++;
411 trace_page_pool_state_hold(pool, page,
412 pool->pages_state_hold_cnt);
415 /* Return last page */
416 if (likely(pool->alloc.count > 0)) {
417 page = pool->alloc.cache[--pool->alloc.count];
418 alloc_stat_inc(pool, slow);
423 /* When page just alloc'ed is should/must have refcnt 1. */
427 /* For using page_pool replace: alloc_pages() API calls, but provide
428 * synchronization guarantee for allocation side.
430 struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
434 /* Fast-path: Get a page from cache */
435 page = __page_pool_get_cached(pool);
439 /* Slow-path: cache empty, do real allocation */
440 page = __page_pool_alloc_pages_slow(pool, gfp);
443 EXPORT_SYMBOL(page_pool_alloc_pages);
445 /* Calculate distance between two u32 values, valid if distance is below 2^(31)
446 * https://en.wikipedia.org/wiki/Serial_number_arithmetic#General_Solution
448 #define _distance(a, b) (s32)((a) - (b))
450 static s32 page_pool_inflight(struct page_pool *pool)
452 u32 release_cnt = atomic_read(&pool->pages_state_release_cnt);
453 u32 hold_cnt = READ_ONCE(pool->pages_state_hold_cnt);
456 inflight = _distance(hold_cnt, release_cnt);
458 trace_page_pool_release(pool, inflight, hold_cnt, release_cnt);
459 WARN(inflight < 0, "Negative(%d) inflight packet-pages", inflight);
464 /* Disconnects a page (from a page_pool). API users can have a need
465 * to disconnect a page (from a page_pool), to allow it to be used as
466 * a regular page (that will eventually be returned to the normal
467 * page-allocator via put_page).
469 void page_pool_release_page(struct page_pool *pool, struct page *page)
474 if (!(pool->p.flags & PP_FLAG_DMA_MAP))
475 /* Always account for inflight pages, even if we didn't
480 dma = page_pool_get_dma_addr(page);
482 /* When page is unmapped, it cannot be returned to our pool */
483 dma_unmap_page_attrs(pool->p.dev, dma,
484 PAGE_SIZE << pool->p.order, pool->p.dma_dir,
485 DMA_ATTR_SKIP_CPU_SYNC);
486 page_pool_set_dma_addr(page, 0);
488 page_pool_clear_pp_info(page);
490 /* This may be the last page returned, releasing the pool, so
491 * it is not safe to reference pool afterwards.
493 count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt);
494 trace_page_pool_state_release(pool, page, count);
496 EXPORT_SYMBOL(page_pool_release_page);
498 /* Return a page to the page allocator, cleaning up our state */
499 static void page_pool_return_page(struct page_pool *pool, struct page *page)
501 page_pool_release_page(pool, page);
504 /* An optimization would be to call __free_pages(page, pool->p.order)
505 * knowing page is not part of page-cache (thus avoiding a
506 * __page_cache_release() call).
510 static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
513 /* BH protection not needed if current is serving softirq */
514 if (in_serving_softirq())
515 ret = ptr_ring_produce(&pool->ring, page);
517 ret = ptr_ring_produce_bh(&pool->ring, page);
520 recycle_stat_inc(pool, ring);
527 /* Only allow direct recycling in special circumstances, into the
528 * alloc side cache. E.g. during RX-NAPI processing for XDP_DROP use-case.
530 * Caller must provide appropriate safe context.
532 static bool page_pool_recycle_in_cache(struct page *page,
533 struct page_pool *pool)
535 if (unlikely(pool->alloc.count == PP_ALLOC_CACHE_SIZE)) {
536 recycle_stat_inc(pool, cache_full);
540 /* Caller MUST have verified/know (page_ref_count(page) == 1) */
541 pool->alloc.cache[pool->alloc.count++] = page;
542 recycle_stat_inc(pool, cached);
546 /* If the page refcnt == 1, this will try to recycle the page.
547 * if PP_FLAG_DMA_SYNC_DEV is set, we'll try to sync the DMA area for
548 * the configured size min(dma_sync_size, pool->max_len).
549 * If the page refcnt != 1, then the page will be returned to memory
552 static __always_inline struct page *
553 __page_pool_put_page(struct page_pool *pool, struct page *page,
554 unsigned int dma_sync_size, bool allow_direct)
556 /* This allocator is optimized for the XDP mode that uses
557 * one-frame-per-page, but have fallbacks that act like the
558 * regular page allocator APIs.
560 * refcnt == 1 means page_pool owns page, and can recycle it.
562 * page is NOT reusable when allocated when system is under
563 * some pressure. (page_is_pfmemalloc)
565 if (likely(page_ref_count(page) == 1 && !page_is_pfmemalloc(page))) {
566 /* Read barrier done in page_ref_count / READ_ONCE */
568 if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
569 page_pool_dma_sync_for_device(pool, page,
572 if (allow_direct && in_serving_softirq() &&
573 page_pool_recycle_in_cache(page, pool))
576 /* Page found as candidate for recycling */
579 /* Fallback/non-XDP mode: API user have elevated refcnt.
581 * Many drivers split up the page into fragments, and some
582 * want to keep doing this to save memory and do refcnt based
583 * recycling. Support this use case too, to ease drivers
584 * switching between XDP/non-XDP.
586 * In-case page_pool maintains the DMA mapping, API user must
587 * call page_pool_put_page once. In this elevated refcnt
588 * case, the DMA is unmapped/released, as driver is likely
589 * doing refcnt based recycle tricks, meaning another process
590 * will be invoking put_page.
592 recycle_stat_inc(pool, released_refcnt);
593 /* Do not replace this with page_pool_return_page() */
594 page_pool_release_page(pool, page);
600 void page_pool_put_defragged_page(struct page_pool *pool, struct page *page,
601 unsigned int dma_sync_size, bool allow_direct)
603 page = __page_pool_put_page(pool, page, dma_sync_size, allow_direct);
604 if (page && !page_pool_recycle_in_ring(pool, page)) {
605 /* Cache full, fallback to free pages */
606 recycle_stat_inc(pool, ring_full);
607 page_pool_return_page(pool, page);
610 EXPORT_SYMBOL(page_pool_put_defragged_page);
612 /* Caller must not use data area after call, as this function overwrites it */
613 void page_pool_put_page_bulk(struct page_pool *pool, void **data,
618 for (i = 0; i < count; i++) {
619 struct page *page = virt_to_head_page(data[i]);
621 /* It is not the last user for the page frag case */
622 if (!page_pool_is_last_frag(pool, page))
625 page = __page_pool_put_page(pool, page, -1, false);
626 /* Approved for bulk recycling in ptr_ring cache */
628 data[bulk_len++] = page;
631 if (unlikely(!bulk_len))
634 /* Bulk producer into ptr_ring page_pool cache */
635 page_pool_ring_lock(pool);
636 for (i = 0; i < bulk_len; i++) {
637 if (__ptr_ring_produce(&pool->ring, data[i])) {
639 recycle_stat_inc(pool, ring_full);
643 recycle_stat_add(pool, ring, i);
644 page_pool_ring_unlock(pool);
646 /* Hopefully all pages was return into ptr_ring */
647 if (likely(i == bulk_len))
650 /* ptr_ring cache full, free remaining pages outside producer lock
651 * since put_page() with refcnt == 1 can be an expensive operation
653 for (; i < bulk_len; i++)
654 page_pool_return_page(pool, data[i]);
656 EXPORT_SYMBOL(page_pool_put_page_bulk);
658 static struct page *page_pool_drain_frag(struct page_pool *pool,
661 long drain_count = BIAS_MAX - pool->frag_users;
663 /* Some user is still using the page frag */
664 if (likely(page_pool_defrag_page(page, drain_count)))
667 if (page_ref_count(page) == 1 && !page_is_pfmemalloc(page)) {
668 if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
669 page_pool_dma_sync_for_device(pool, page, -1);
674 page_pool_return_page(pool, page);
678 static void page_pool_free_frag(struct page_pool *pool)
680 long drain_count = BIAS_MAX - pool->frag_users;
681 struct page *page = pool->frag_page;
683 pool->frag_page = NULL;
685 if (!page || page_pool_defrag_page(page, drain_count))
688 page_pool_return_page(pool, page);
691 struct page *page_pool_alloc_frag(struct page_pool *pool,
692 unsigned int *offset,
693 unsigned int size, gfp_t gfp)
695 unsigned int max_size = PAGE_SIZE << pool->p.order;
696 struct page *page = pool->frag_page;
698 if (WARN_ON(!(pool->p.flags & PP_FLAG_PAGE_FRAG) ||
702 size = ALIGN(size, dma_get_cache_alignment());
703 *offset = pool->frag_offset;
705 if (page && *offset + size > max_size) {
706 page = page_pool_drain_frag(pool, page);
708 alloc_stat_inc(pool, fast);
714 page = page_pool_alloc_pages(pool, gfp);
715 if (unlikely(!page)) {
716 pool->frag_page = NULL;
720 pool->frag_page = page;
723 pool->frag_users = 1;
725 pool->frag_offset = size;
726 page_pool_fragment_page(page, BIAS_MAX);
731 pool->frag_offset = *offset + size;
732 alloc_stat_inc(pool, fast);
735 EXPORT_SYMBOL(page_pool_alloc_frag);
737 static void page_pool_empty_ring(struct page_pool *pool)
741 /* Empty recycle ring */
742 while ((page = ptr_ring_consume_bh(&pool->ring))) {
743 /* Verify the refcnt invariant of cached pages */
744 if (!(page_ref_count(page) == 1))
745 pr_crit("%s() page_pool refcnt %d violation\n",
746 __func__, page_ref_count(page));
748 page_pool_return_page(pool, page);
752 static void page_pool_free(struct page_pool *pool)
754 if (pool->disconnect)
755 pool->disconnect(pool);
757 ptr_ring_cleanup(&pool->ring, NULL);
759 if (pool->p.flags & PP_FLAG_DMA_MAP)
760 put_device(pool->p.dev);
762 #ifdef CONFIG_PAGE_POOL_STATS
763 free_percpu(pool->recycle_stats);
768 static void page_pool_empty_alloc_cache_once(struct page_pool *pool)
772 if (pool->destroy_cnt)
775 /* Empty alloc cache, assume caller made sure this is
776 * no-longer in use, and page_pool_alloc_pages() cannot be
779 while (pool->alloc.count) {
780 page = pool->alloc.cache[--pool->alloc.count];
781 page_pool_return_page(pool, page);
785 static void page_pool_scrub(struct page_pool *pool)
787 page_pool_empty_alloc_cache_once(pool);
790 /* No more consumers should exist, but producers could still
793 page_pool_empty_ring(pool);
796 static int page_pool_release(struct page_pool *pool)
800 page_pool_scrub(pool);
801 inflight = page_pool_inflight(pool);
803 page_pool_free(pool);
808 static void page_pool_release_retry(struct work_struct *wq)
810 struct delayed_work *dwq = to_delayed_work(wq);
811 struct page_pool *pool = container_of(dwq, typeof(*pool), release_dw);
814 inflight = page_pool_release(pool);
818 /* Periodic warning */
819 if (time_after_eq(jiffies, pool->defer_warn)) {
820 int sec = (s32)((u32)jiffies - (u32)pool->defer_start) / HZ;
822 pr_warn("%s() stalled pool shutdown %d inflight %d sec\n",
823 __func__, inflight, sec);
824 pool->defer_warn = jiffies + DEFER_WARN_INTERVAL;
827 /* Still not ready to be disconnected, retry later */
828 schedule_delayed_work(&pool->release_dw, DEFER_TIME);
831 void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *),
832 struct xdp_mem_info *mem)
834 refcount_inc(&pool->user_cnt);
835 pool->disconnect = disconnect;
836 pool->xdp_mem_id = mem->id;
839 void page_pool_destroy(struct page_pool *pool)
844 if (!page_pool_put(pool))
847 page_pool_free_frag(pool);
849 if (!page_pool_release(pool))
852 pool->defer_start = jiffies;
853 pool->defer_warn = jiffies + DEFER_WARN_INTERVAL;
855 INIT_DELAYED_WORK(&pool->release_dw, page_pool_release_retry);
856 schedule_delayed_work(&pool->release_dw, DEFER_TIME);
858 EXPORT_SYMBOL(page_pool_destroy);
860 /* Caller must provide appropriate safe context, e.g. NAPI. */
861 void page_pool_update_nid(struct page_pool *pool, int new_nid)
865 trace_page_pool_update_nid(pool, new_nid);
866 pool->p.nid = new_nid;
868 /* Flush pool alloc cache, as refill will check NUMA node */
869 while (pool->alloc.count) {
870 page = pool->alloc.cache[--pool->alloc.count];
871 page_pool_return_page(pool, page);
874 EXPORT_SYMBOL(page_pool_update_nid);
876 bool page_pool_return_skb_page(struct page *page)
878 struct page_pool *pp;
880 page = compound_head(page);
882 /* page->pp_magic is OR'ed with PP_SIGNATURE after the allocation
883 * in order to preserve any existing bits, such as bit 0 for the
884 * head page of compound page and bit 1 for pfmemalloc page, so
885 * mask those bits for freeing side when doing below checking,
886 * and page_is_pfmemalloc() is checked in __page_pool_put_page()
887 * to avoid recycling the pfmemalloc page.
889 if (unlikely((page->pp_magic & ~0x3UL) != PP_SIGNATURE))
894 /* Driver set this to memory recycling info. Reset it on recycle.
895 * This will *not* work for NIC using a split-page memory model.
896 * The page will be returned to the pool here regardless of the
897 * 'flipped' fragment being in use or not.
899 page_pool_put_full_page(pp, page, false);
903 EXPORT_SYMBOL(page_pool_return_skb_page);