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page_pool: convert to use netmem

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Abstract the memory type from the page_pool so we can later add support
for new memory types. Convert the page_pool to use the new netmem type
abstraction, rather than use struct page directly.

As of this patch the netmem type is a no-op abstraction: it's always a
struct page underneath. All the page pool internals are converted to
use struct netmem instead of struct page, and the page pool now exports
2 APIs:

1. The existing struct page API.
2. The new struct netmem API.

Keeping the existing API is transitional; we do not want to refactor all
the current drivers using the page pool at once.

The netmem abstraction is currently a no-op. The page_pool uses
page_to_netmem() to convert allocated pages to netmem, and uses
netmem_to_page() to convert the netmem back to pages to pass to mm APIs,

Follow up patches to this series add non-paged netmem support to the
page_pool. This change is factored out on its own to limit the code
churn to this 1 patch, for ease of code review.

Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/20240628003253.1694510-6-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Mina Almasry 2024-06-28 00:32:42 +00:00 committed by Jakub Kicinski
parent ac26327635
commit 4dec64c52e
8 changed files with 288 additions and 185 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/linux/skbuff_ref.h
View File

@ -32,13 +32,13 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f)
__skb_frag_ref(&skb_shinfo(skb)->frags[f]);
}
bool napi_pp_put_page(struct page *page);
bool napi_pp_put_page(netmem_ref netmem);
static inline void
skb_page_unref(struct page *page, bool recycle)
{
#ifdef CONFIG_PAGE_POOL
if (recycle && napi_pp_put_page(page))
if (recycle && napi_pp_put_page(page_to_netmem(page)))
return;
#endif
put_page(page);

15
include/net/netmem.h
View File

@ -38,4 +38,19 @@ static inline netmem_ref page_to_netmem(struct page *page)
return (__force netmem_ref)page;
}
static inline int netmem_ref_count(netmem_ref netmem)
{
return page_ref_count(netmem_to_page(netmem));
}
static inline unsigned long netmem_to_pfn(netmem_ref netmem)
{
return page_to_pfn(netmem_to_page(netmem));
}
static inline netmem_ref netmem_compound_head(netmem_ref netmem)
{
return page_to_netmem(compound_head(netmem_to_page(netmem)));
}
#endif /* _NET_NETMEM_H */

93
include/net/page_pool/helpers.h
View File

@ -55,6 +55,8 @@
#include <linux/dma-mapping.h>
#include <net/page_pool/types.h>
#include <net/net_debug.h>
#include <net/netmem.h>
#ifdef CONFIG_PAGE_POOL_STATS
/* Deprecated driver-facing API, use netlink instead */
@ -212,6 +214,11 @@ page_pool_get_dma_dir(const struct page_pool *pool)
return pool->p.dma_dir;
}
static inline void page_pool_fragment_netmem(netmem_ref netmem, long nr)
{
atomic_long_set(&netmem_to_page(netmem)->pp_ref_count, nr);
}
/**
* page_pool_fragment_page() - split a fresh page into fragments
* @page: page to split
@ -232,11 +239,12 @@ page_pool_get_dma_dir(const struct page_pool *pool)
*/
static inline void page_pool_fragment_page(struct page *page, long nr)
{
atomic_long_set(&page->pp_ref_count, nr);
page_pool_fragment_netmem(page_to_netmem(page), nr);
}
static inline long page_pool_unref_page(struct page *page, long nr)
static inline long page_pool_unref_netmem(netmem_ref netmem, long nr)
{
struct page *page = netmem_to_page(netmem);
long ret;
/* If nr == pp_ref_count then we have cleared all remaining
@ -279,15 +287,41 @@ static inline long page_pool_unref_page(struct page *page, long nr)
return ret;
}
static inline void page_pool_ref_page(struct page *page)
static inline long page_pool_unref_page(struct page *page, long nr)
{
atomic_long_inc(&page->pp_ref_count);
return page_pool_unref_netmem(page_to_netmem(page), nr);
}
static inline bool page_pool_is_last_ref(struct page *page)
static inline void page_pool_ref_netmem(netmem_ref netmem)
{
atomic_long_inc(&netmem_to_page(netmem)->pp_ref_count);
}
static inline void page_pool_ref_page(struct page *page)
{
page_pool_ref_netmem(page_to_netmem(page));
}
static inline bool page_pool_is_last_ref(netmem_ref netmem)
{
/* If page_pool_unref_page() returns 0, we were the last user */
return page_pool_unref_page(page, 1) == 0;
return page_pool_unref_netmem(netmem, 1) == 0;
}
static inline void page_pool_put_netmem(struct page_pool *pool,
netmem_ref netmem,
unsigned int dma_sync_size,
bool allow_direct)
{
/* When page_pool isn't compiled-in, net/core/xdp.c doesn't
* allow registering MEM_TYPE_PAGE_POOL, but shield linker.
*/
#ifdef CONFIG_PAGE_POOL
if (!page_pool_is_last_ref(netmem))
return;
page_pool_put_unrefed_netmem(pool, netmem, dma_sync_size, allow_direct);
#endif
}
/**
@ -308,15 +342,15 @@ static inline void page_pool_put_page(struct page_pool *pool,
unsigned int dma_sync_size,
bool allow_direct)
{
/* When page_pool isn't compiled-in, net/core/xdp.c doesn't
* allow registering MEM_TYPE_PAGE_POOL, but shield linker.
*/
#ifdef CONFIG_PAGE_POOL
if (!page_pool_is_last_ref(page))
return;
page_pool_put_netmem(pool, page_to_netmem(page), dma_sync_size,
allow_direct);
}
page_pool_put_unrefed_page(pool, page, dma_sync_size, allow_direct);
#endif
static inline void page_pool_put_full_netmem(struct page_pool *pool,
netmem_ref netmem,
bool allow_direct)
{
page_pool_put_netmem(pool, netmem, -1, allow_direct);
}
/**
@ -331,7 +365,7 @@ static inline void page_pool_put_page(struct page_pool *pool,
static inline void page_pool_put_full_page(struct page_pool *pool,
struct page *page, bool allow_direct)
{
page_pool_put_page(pool, page, -1, allow_direct);
page_pool_put_netmem(pool, page_to_netmem(page), -1, allow_direct);
}
/**
@ -365,6 +399,18 @@ static inline void page_pool_free_va(struct page_pool *pool, void *va,
page_pool_put_page(pool, virt_to_head_page(va), -1, allow_direct);
}
static inline dma_addr_t page_pool_get_dma_addr_netmem(netmem_ref netmem)
{
struct page *page = netmem_to_page(netmem);
dma_addr_t ret = page->dma_addr;
if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
ret <<= PAGE_SHIFT;
return ret;
}
/**
* page_pool_get_dma_addr() - Retrieve the stored DMA address.
* @page: page allocated from a page pool
@ -374,16 +420,14 @@ static inline void page_pool_free_va(struct page_pool *pool, void *va,
*/
static inline dma_addr_t page_pool_get_dma_addr(const struct page *page)
{
dma_addr_t ret = page->dma_addr;
if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
ret <<= PAGE_SHIFT;
return ret;
return page_pool_get_dma_addr_netmem(page_to_netmem((struct page *)page));
}
static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
static inline bool page_pool_set_dma_addr_netmem(netmem_ref netmem,
dma_addr_t addr)
{
struct page *page = netmem_to_page(netmem);
if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) {
page->dma_addr = addr >> PAGE_SHIFT;
@ -419,6 +463,11 @@ static inline void page_pool_dma_sync_for_cpu(const struct page_pool *pool,
page_pool_get_dma_dir(pool));
}
static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
{
return page_pool_set_dma_addr_netmem(page_to_netmem(page), addr);
}
static inline bool page_pool_put(struct page_pool *pool)
{
return refcount_dec_and_test(&pool->user_cnt);

14
include/net/page_pool/types.h
View File

@ -6,6 +6,7 @@
#include <linux/dma-direction.h>
#include <linux/ptr_ring.h>
#include <linux/types.h>
#include <net/netmem.h>
#define PP_FLAG_DMA_MAP BIT(0) /* Should page_pool do the DMA
* map/unmap
@ -40,7 +41,7 @@
#define PP_ALLOC_CACHE_REFILL 64
struct pp_alloc_cache {
u32 count;
struct page *cache[PP_ALLOC_CACHE_SIZE];
netmem_ref cache[PP_ALLOC_CACHE_SIZE];
};
/**
@ -73,7 +74,7 @@ struct page_pool_params {
struct net_device *netdev;
unsigned int flags;
/* private: used by test code only */
void (*init_callback)(struct page *page, void *arg);
void (*init_callback)(netmem_ref netmem, void *arg);
void *init_arg;
);
};
@ -151,7 +152,7 @@ struct page_pool {
*/
__cacheline_group_begin(frag) __aligned(4 * sizeof(long));
long frag_users;
struct page *frag_page;
netmem_ref frag_page;
unsigned int frag_offset;
__cacheline_group_end(frag);
@ -220,8 +221,12 @@ struct page_pool {
};
struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);
netmem_ref page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp);
struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset,
unsigned int size, gfp_t gfp);
netmem_ref page_pool_alloc_frag_netmem(struct page_pool *pool,
unsigned int *offset, unsigned int size,
gfp_t gfp);
struct page_pool *page_pool_create(const struct page_pool_params *params);
struct page_pool *page_pool_create_percpu(const struct page_pool_params *params,
int cpuid);
@ -252,6 +257,9 @@ static inline void page_pool_put_page_bulk(struct page_pool *pool, void **data,
}
#endif
void page_pool_put_unrefed_netmem(struct page_pool *pool, netmem_ref netmem,
unsigned int dma_sync_size,
bool allow_direct);
void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page,
unsigned int dma_sync_size,
bool allow_direct);

30
include/trace/events/page_pool.h
View File

@ -42,51 +42,53 @@ TRACE_EVENT(page_pool_release,
TRACE_EVENT(page_pool_state_release,
TP_PROTO(const struct page_pool *pool,
const struct page *page, u32 release),
netmem_ref netmem, u32 release),
TP_ARGS(pool, page, release),
TP_ARGS(pool, netmem, release),
TP_STRUCT__entry(
__field(const struct page_pool *, pool)
__field(const struct page *, page)
__field(unsigned long, netmem)
__field(u32, release)
__field(unsigned long, pfn)
),
TP_fast_assign(
__entry->pool = pool;
__entry->page = page;
__entry->netmem = (__force unsigned long)netmem;
__entry->release = release;
__entry->pfn = page_to_pfn(page);
__entry->pfn = netmem_to_pfn(netmem);
),
TP_printk("page_pool=%p page=%p pfn=0x%lx release=%u",
__entry->pool, __entry->page, __entry->pfn, __entry->release)
TP_printk("page_pool=%p netmem=%p pfn=0x%lx release=%u",
__entry->pool, (void *)__entry->netmem,
__entry->pfn, __entry->release)
);
TRACE_EVENT(page_pool_state_hold,
TP_PROTO(const struct page_pool *pool,
const struct page *page, u32 hold),
netmem_ref netmem, u32 hold),
TP_ARGS(pool, page, hold),
TP_ARGS(pool, netmem, hold),
TP_STRUCT__entry(
__field(const struct page_pool *, pool)
__field(const struct page *, page)
__field(unsigned long, netmem)
__field(u32, hold)
__field(unsigned long, pfn)
),
TP_fast_assign(
__entry->pool = pool;
__entry->page = page;
__entry->netmem = (__force unsigned long)netmem;
__entry->hold = hold;
__entry->pfn = page_to_pfn(page);
__entry->pfn = netmem_to_pfn(netmem);
),
TP_printk("page_pool=%p page=%p pfn=0x%lx hold=%u",
__entry->pool, __entry->page, __entry->pfn, __entry->hold)
TP_printk("page_pool=%p netmem=%p pfn=0x%lx hold=%u",
__entry->pool, (void *)__entry->netmem,
__entry->pfn, __entry->hold)
);
TRACE_EVENT(page_pool_update_nid,

5
net/bpf/test_run.c
View File

@ -127,9 +127,10 @@ struct xdp_test_data {
#define TEST_XDP_FRAME_SIZE (PAGE_SIZE - sizeof(struct xdp_page_head))
#define TEST_XDP_MAX_BATCH 256
static void xdp_test_run_init_page(struct page *page, void *arg)
static void xdp_test_run_init_page(netmem_ref netmem, void *arg)
{
struct xdp_page_head *head = phys_to_virt(page_to_phys(page));
struct xdp_page_head *head =
phys_to_virt(page_to_phys(netmem_to_page(netmem)));
struct xdp_buff *new_ctx, *orig_ctx;
u32 headroom = XDP_PACKET_HEADROOM;
struct xdp_test_data *xdp = arg;

304
net/core/page_pool.c
View File

@ -327,19 +327,18 @@ struct page_pool *page_pool_create(const struct page_pool_params *params)
}
EXPORT_SYMBOL(page_pool_create);
static void page_pool_return_page(struct page_pool *pool, struct page *page);
static void page_pool_return_page(struct page_pool *pool, netmem_ref netmem);
noinline
static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)
static noinline netmem_ref page_pool_refill_alloc_cache(struct page_pool *pool)
{
struct ptr_ring *r = &pool->ring;
struct page *page;
netmem_ref netmem;
int pref_nid; /* preferred NUMA node */
/* Quicker fallback, avoid locks when ring is empty */
if (__ptr_ring_empty(r)) {
alloc_stat_inc(pool, empty);
return NULL;
return 0;
}
/* Softirq guarantee CPU and thus NUMA node is stable. This,
@ -354,57 +353,57 @@ static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)
/* Refill alloc array, but only if NUMA match */
do {
page = __ptr_ring_consume(r);
if (unlikely(!page))
netmem = (__force netmem_ref)__ptr_ring_consume(r);
if (unlikely(!netmem))
break;
if (likely(page_to_nid(page) == pref_nid)) {
pool->alloc.cache[pool->alloc.count++] = page;
if (likely(page_to_nid(netmem_to_page(netmem)) == pref_nid)) {
pool->alloc.cache[pool->alloc.count++] = netmem;
} else {
/* NUMA mismatch;
* (1) release 1 page to page-allocator and
* (2) break out to fallthrough to alloc_pages_node.
* This limit stress on page buddy alloactor.
*/
page_pool_return_page(pool, page);
page_pool_return_page(pool, netmem);
alloc_stat_inc(pool, waive);
page = NULL;
netmem = 0;
break;
}
} while (pool->alloc.count < PP_ALLOC_CACHE_REFILL);
/* Return last page */
if (likely(pool->alloc.count > 0)) {
page = pool->alloc.cache[--pool->alloc.count];
netmem = pool->alloc.cache[--pool->alloc.count];
alloc_stat_inc(pool, refill);
}
return page;
return netmem;
}
/* fast path */
static struct page *__page_pool_get_cached(struct page_pool *pool)
static netmem_ref __page_pool_get_cached(struct page_pool *pool)
{
struct page *page;
netmem_ref netmem;
/* Caller MUST guarantee safe non-concurrent access, e.g. softirq */
if (likely(pool->alloc.count)) {
/* Fast-path */
page = pool->alloc.cache[--pool->alloc.count];
netmem = pool->alloc.cache[--pool->alloc.count];
alloc_stat_inc(pool, fast);
} else {
page = page_pool_refill_alloc_cache(pool);
netmem = page_pool_refill_alloc_cache(pool);
}
return page;
return netmem;
}
static void __page_pool_dma_sync_for_device(const struct page_pool *pool,
const struct page *page,
netmem_ref netmem,
u32 dma_sync_size)
{
#if defined(CONFIG_HAS_DMA) && defined(CONFIG_DMA_NEED_SYNC)
dma_addr_t dma_addr = page_pool_get_dma_addr(page);
dma_addr_t dma_addr = page_pool_get_dma_addr_netmem(netmem);
dma_sync_size = min(dma_sync_size, pool->p.max_len);
__dma_sync_single_for_device(pool->p.dev, dma_addr + pool->p.offset,
@ -414,14 +413,14 @@ static void __page_pool_dma_sync_for_device(const struct page_pool *pool,
static __always_inline void
page_pool_dma_sync_for_device(const struct page_pool *pool,
const struct page *page,
netmem_ref netmem,
u32 dma_sync_size)
{
if (pool->dma_sync && dma_dev_need_sync(pool->p.dev))
__page_pool_dma_sync_for_device(pool, page, dma_sync_size);
__page_pool_dma_sync_for_device(pool, netmem, dma_sync_size);
}
static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem)
{
dma_addr_t dma;
@ -430,17 +429,17 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
* into page private data (i.e 32bit cpu with 64bit DMA caps)
* This mapping is kept for lifetime of page, until leaving pool.
*/
dma = dma_map_page_attrs(pool->p.dev, page, 0,
(PAGE_SIZE << pool->p.order),
pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC |
DMA_ATTR_WEAK_ORDERING);
dma = dma_map_page_attrs(pool->p.dev, netmem_to_page(netmem), 0,
(PAGE_SIZE << pool->p.order), pool->p.dma_dir,
DMA_ATTR_SKIP_CPU_SYNC |
DMA_ATTR_WEAK_ORDERING);
if (dma_mapping_error(pool->p.dev, dma))
return false;
if (page_pool_set_dma_addr(page, dma))
if (page_pool_set_dma_addr_netmem(netmem, dma))
goto unmap_failed;
page_pool_dma_sync_for_device(pool, page, pool->p.max_len);
page_pool_dma_sync_for_device(pool, netmem, pool->p.max_len);
return true;
@ -452,9 +451,10 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
return false;
}
static void page_pool_set_pp_info(struct page_pool *pool,
struct page *page)
static void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem)
{
struct page *page = netmem_to_page(netmem);
page->pp = pool;
page->pp_magic |= PP_SIGNATURE;
@ -464,13 +464,15 @@ static void page_pool_set_pp_info(struct page_pool *pool,
* is dirtying the same cache line as the page->pp_magic above, so
* the overhead is negligible.
*/
page_pool_fragment_page(page, 1);
page_pool_fragment_netmem(netmem, 1);
if (pool->has_init_callback)
pool->slow.init_callback(page, pool->slow.init_arg);
pool->slow.init_callback(netmem, pool->slow.init_arg);
}
static void page_pool_clear_pp_info(struct page *page)
static void page_pool_clear_pp_info(netmem_ref netmem)
{
struct page *page = netmem_to_page(netmem);
page->pp_magic = 0;
page->pp = NULL;
}
@ -485,34 +487,34 @@ static struct page *__page_pool_alloc_page_order(struct page_pool *pool,
if (unlikely(!page))
return NULL;
if (pool->dma_map && unlikely(!page_pool_dma_map(pool, page))) {
if (pool->dma_map && unlikely(!page_pool_dma_map(pool, page_to_netmem(page)))) {
put_page(page);
return NULL;
}
alloc_stat_inc(pool, slow_high_order);
page_pool_set_pp_info(pool, page);
page_pool_set_pp_info(pool, page_to_netmem(page));
/* Track how many pages are held 'in-flight' */
pool->pages_state_hold_cnt++;
trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt);
trace_page_pool_state_hold(pool, page_to_netmem(page),
pool->pages_state_hold_cnt);
return page;
}
/* slow path */
noinline
static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
gfp_t gfp)
static noinline netmem_ref __page_pool_alloc_pages_slow(struct page_pool *pool,
gfp_t gfp)
{
const int bulk = PP_ALLOC_CACHE_REFILL;
unsigned int pp_order = pool->p.order;
bool dma_map = pool->dma_map;
struct page *page;
netmem_ref netmem;
int i, nr_pages;
/* Don't support bulk alloc for high-order pages */
if (unlikely(pp_order))
return __page_pool_alloc_page_order(pool, gfp);
return page_to_netmem(__page_pool_alloc_page_order(pool, gfp));
/* Unnecessary as alloc cache is empty, but guarantees zero count */
if (unlikely(pool->alloc.count > 0))
@ -521,56 +523,63 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
/* Mark empty alloc.cache slots "empty" for alloc_pages_bulk_array */
memset(&pool->alloc.cache, 0, sizeof(void *) * bulk);
nr_pages = alloc_pages_bulk_array_node(gfp, pool->p.nid, bulk,
pool->alloc.cache);
nr_pages = alloc_pages_bulk_array_node(gfp,
pool->p.nid, bulk,
(struct page **)pool->alloc.cache);
if (unlikely(!nr_pages))
return NULL;
return 0;
/* Pages have been filled into alloc.cache array, but count is zero and
* page element have not been (possibly) DMA mapped.
*/
for (i = 0; i < nr_pages; i++) {
page = pool->alloc.cache[i];
if (dma_map && unlikely(!page_pool_dma_map(pool, page))) {
put_page(page);
netmem = pool->alloc.cache[i];
if (dma_map && unlikely(!page_pool_dma_map(pool, netmem))) {
put_page(netmem_to_page(netmem));
continue;
}
page_pool_set_pp_info(pool, page);
pool->alloc.cache[pool->alloc.count++] = page;
page_pool_set_pp_info(pool, netmem);
pool->alloc.cache[pool->alloc.count++] = netmem;
/* Track how many pages are held 'in-flight' */
pool->pages_state_hold_cnt++;
trace_page_pool_state_hold(pool, page,
trace_page_pool_state_hold(pool, netmem,
pool->pages_state_hold_cnt);
}
/* Return last page */
if (likely(pool->alloc.count > 0)) {
page = pool->alloc.cache[--pool->alloc.count];
netmem = pool->alloc.cache[--pool->alloc.count];
alloc_stat_inc(pool, slow);
} else {
page = NULL;
netmem = 0;
}
/* When page just alloc'ed is should/must have refcnt 1. */
return page;
return netmem;
}
/* For using page_pool replace: alloc_pages() API calls, but provide
* synchronization guarantee for allocation side.
*/
struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
netmem_ref page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp)
{
struct page *page;
netmem_ref netmem;
/* Fast-path: Get a page from cache */
page = __page_pool_get_cached(pool);
if (page)
return page;
netmem = __page_pool_get_cached(pool);
if (netmem)
return netmem;
/* Slow-path: cache empty, do real allocation */
page = __page_pool_alloc_pages_slow(pool, gfp);
return page;
netmem = __page_pool_alloc_pages_slow(pool, gfp);
return netmem;
}
EXPORT_SYMBOL(page_pool_alloc_netmem);
struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
{
return netmem_to_page(page_pool_alloc_netmem(pool, gfp));
}
EXPORT_SYMBOL(page_pool_alloc_pages);
ALLOW_ERROR_INJECTION(page_pool_alloc_pages, NULL);
@ -599,8 +608,8 @@ s32 page_pool_inflight(const struct page_pool *pool, bool strict)
return inflight;
}
static __always_inline
void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
static __always_inline void __page_pool_release_page_dma(struct page_pool *pool,
netmem_ref netmem)
{
dma_addr_t dma;
@ -610,13 +619,13 @@ void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
*/
return;
dma = page_pool_get_dma_addr(page);
dma = page_pool_get_dma_addr_netmem(netmem);
/* When page is unmapped, it cannot be returned to our pool */
dma_unmap_page_attrs(pool->p.dev, dma,
PAGE_SIZE << pool->p.order, pool->p.dma_dir,
DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING);
page_pool_set_dma_addr(page, 0);
page_pool_set_dma_addr_netmem(netmem, 0);
}
/* Disconnects a page (from a page_pool). API users can have a need
@ -624,35 +633,34 @@ void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
* a regular page (that will eventually be returned to the normal
* page-allocator via put_page).
*/
void page_pool_return_page(struct page_pool *pool, struct page *page)
void page_pool_return_page(struct page_pool *pool, netmem_ref netmem)
{
int count;
__page_pool_release_page_dma(pool, page);
page_pool_clear_pp_info(page);
__page_pool_release_page_dma(pool, netmem);
/* This may be the last page returned, releasing the pool, so
* it is not safe to reference pool afterwards.
*/
count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt);
trace_page_pool_state_release(pool, page, count);
trace_page_pool_state_release(pool, netmem, count);
put_page(page);
page_pool_clear_pp_info(netmem);
put_page(netmem_to_page(netmem));
/* An optimization would be to call __free_pages(page, pool->p.order)
* knowing page is not part of page-cache (thus avoiding a
* __page_cache_release() call).
*/
}
static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
static bool page_pool_recycle_in_ring(struct page_pool *pool, netmem_ref netmem)
{
int ret;
/* BH protection not needed if current is softirq */
if (in_softirq())
ret = ptr_ring_produce(&pool->ring, page);
ret = ptr_ring_produce(&pool->ring, (__force void *)netmem);
else
ret = ptr_ring_produce_bh(&pool->ring, page);
ret = ptr_ring_produce_bh(&pool->ring, (__force void *)netmem);
if (!ret) {
recycle_stat_inc(pool, ring);
@ -667,7 +675,7 @@ static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
*
* Caller must provide appropriate safe context.
*/
static bool page_pool_recycle_in_cache(struct page *page,
static bool page_pool_recycle_in_cache(netmem_ref netmem,
struct page_pool *pool)
{
if (unlikely(pool->alloc.count == PP_ALLOC_CACHE_SIZE)) {
@ -676,14 +684,15 @@ static bool page_pool_recycle_in_cache(struct page *page,
}
/* Caller MUST have verified/know (page_ref_count(page) == 1) */
pool->alloc.cache[pool->alloc.count++] = page;
pool->alloc.cache[pool->alloc.count++] = netmem;
recycle_stat_inc(pool, cached);
return true;
}
static bool __page_pool_page_can_be_recycled(const struct page *page)
static bool __page_pool_page_can_be_recycled(netmem_ref netmem)
{
return page_ref_count(page) == 1 && !page_is_pfmemalloc(page);
return page_ref_count(netmem_to_page(netmem)) == 1 &&
!page_is_pfmemalloc(netmem_to_page(netmem));
}
/* If the page refcnt == 1, this will try to recycle the page.
@ -692,8 +701,8 @@ static bool __page_pool_page_can_be_recycled(const struct page *page)
* If the page refcnt != 1, then the page will be returned to memory
* subsystem.
*/
static __always_inline struct page *
__page_pool_put_page(struct page_pool *pool, struct page *page,
static __always_inline netmem_ref
__page_pool_put_page(struct page_pool *pool, netmem_ref netmem,
unsigned int dma_sync_size, bool allow_direct)
{
lockdep_assert_no_hardirq();
@ -707,16 +716,16 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
* page is NOT reusable when allocated when system is under
* some pressure. (page_is_pfmemalloc)
*/
if (likely(__page_pool_page_can_be_recycled(page))) {
if (likely(__page_pool_page_can_be_recycled(netmem))) {
/* Read barrier done in page_ref_count / READ_ONCE */
page_pool_dma_sync_for_device(pool, page, dma_sync_size);
page_pool_dma_sync_for_device(pool, netmem, dma_sync_size);
if (allow_direct && page_pool_recycle_in_cache(page, pool))
return NULL;
if (allow_direct && page_pool_recycle_in_cache(netmem, pool))
return 0;
/* Page found as candidate for recycling */
return page;
return netmem;
}
/* Fallback/non-XDP mode: API user have elevated refcnt.
*
@ -732,9 +741,9 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
* will be invoking put_page.
*/
recycle_stat_inc(pool, released_refcnt);
page_pool_return_page(pool, page);
page_pool_return_page(pool, netmem);
return NULL;
return 0;
}
static bool page_pool_napi_local(const struct page_pool *pool)
@ -760,19 +769,28 @@ static bool page_pool_napi_local(const struct page_pool *pool)
return napi && READ_ONCE(napi->list_owner) == cpuid;
}
void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page,
unsigned int dma_sync_size, bool allow_direct)
void page_pool_put_unrefed_netmem(struct page_pool *pool, netmem_ref netmem,
unsigned int dma_sync_size, bool allow_direct)
{
if (!allow_direct)
allow_direct = page_pool_napi_local(pool);
page = __page_pool_put_page(pool, page, dma_sync_size, allow_direct);
if (page && !page_pool_recycle_in_ring(pool, page)) {
netmem =
__page_pool_put_page(pool, netmem, dma_sync_size, allow_direct);
if (netmem && !page_pool_recycle_in_ring(pool, netmem)) {
/* Cache full, fallback to free pages */
recycle_stat_inc(pool, ring_full);
page_pool_return_page(pool, page);
page_pool_return_page(pool, netmem);
}
}
EXPORT_SYMBOL(page_pool_put_unrefed_netmem);
void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page,
unsigned int dma_sync_size, bool allow_direct)
{
page_pool_put_unrefed_netmem(pool, page_to_netmem(page), dma_sync_size,
allow_direct);
}
EXPORT_SYMBOL(page_pool_put_unrefed_page);
/**
@ -800,16 +818,16 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data,
allow_direct = page_pool_napi_local(pool);
for (i = 0; i < count; i++) {
struct page *page = virt_to_head_page(data[i]);
netmem_ref netmem = page_to_netmem(virt_to_head_page(data[i]));
/* It is not the last user for the page frag case */
if (!page_pool_is_last_ref(page))
if (!page_pool_is_last_ref(netmem))
continue;
page = __page_pool_put_page(pool, page, -1, allow_direct);
netmem = __page_pool_put_page(pool, netmem, -1, allow_direct);
/* Approved for bulk recycling in ptr_ring cache */
if (page)
data[bulk_len++] = page;
if (netmem)
data[bulk_len++] = (__force void *)netmem;
}
if (!bulk_len)
@ -835,98 +853,106 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data,
* since put_page() with refcnt == 1 can be an expensive operation
*/
for (; i < bulk_len; i++)
page_pool_return_page(pool, data[i]);
page_pool_return_page(pool, (__force netmem_ref)data[i]);
}
EXPORT_SYMBOL(page_pool_put_page_bulk);
static struct page *page_pool_drain_frag(struct page_pool *pool,
struct page *page)
static netmem_ref page_pool_drain_frag(struct page_pool *pool,
netmem_ref netmem)
{
long drain_count = BIAS_MAX - pool->frag_users;
/* Some user is still using the page frag */
if (likely(page_pool_unref_page(page, drain_count)))
return NULL;
if (likely(page_pool_unref_netmem(netmem, drain_count)))
return 0;
if (__page_pool_page_can_be_recycled(page)) {
page_pool_dma_sync_for_device(pool, page, -1);
return page;
if (__page_pool_page_can_be_recycled(netmem)) {
page_pool_dma_sync_for_device(pool, netmem, -1);
return netmem;
}
page_pool_return_page(pool, page);
return NULL;
page_pool_return_page(pool, netmem);
return 0;
}
static void page_pool_free_frag(struct page_pool *pool)
{
long drain_count = BIAS_MAX - pool->frag_users;
struct page *page = pool->frag_page;
netmem_ref netmem = pool->frag_page;
pool->frag_page = NULL;
pool->frag_page = 0;
if (!page || page_pool_unref_page(page, drain_count))
if (!netmem || page_pool_unref_netmem(netmem, drain_count))
return;
page_pool_return_page(pool, page);
page_pool_return_page(pool, netmem);
}
struct page *page_pool_alloc_frag(struct page_pool *pool,
unsigned int *offset,
unsigned int size, gfp_t gfp)
netmem_ref page_pool_alloc_frag_netmem(struct page_pool *pool,
unsigned int *offset, unsigned int size,
gfp_t gfp)
{
unsigned int max_size = PAGE_SIZE << pool->p.order;
struct page *page = pool->frag_page;
netmem_ref netmem = pool->frag_page;
if (WARN_ON(size > max_size))
return NULL;
return 0;
size = ALIGN(size, dma_get_cache_alignment());
*offset = pool->frag_offset;
if (page && *offset + size > max_size) {
page = page_pool_drain_frag(pool, page);
if (page) {
if (netmem && *offset + size > max_size) {
netmem = page_pool_drain_frag(pool, netmem);
if (netmem) {
alloc_stat_inc(pool, fast);
goto frag_reset;
}
}
if (!page) {
page = page_pool_alloc_pages(pool, gfp);
if (unlikely(!page)) {
pool->frag_page = NULL;
return NULL;
if (!netmem) {
netmem = page_pool_alloc_netmem(pool, gfp);
if (unlikely(!netmem)) {
pool->frag_page = 0;
return 0;
}
pool->frag_page = page;
pool->frag_page = netmem;
frag_reset:
pool->frag_users = 1;
*offset = 0;
pool->frag_offset = size;
page_pool_fragment_page(page, BIAS_MAX);
return page;
page_pool_fragment_netmem(netmem, BIAS_MAX);
return netmem;
}
pool->frag_users++;
pool->frag_offset = *offset + size;
alloc_stat_inc(pool, fast);
return page;
return netmem;
}
EXPORT_SYMBOL(page_pool_alloc_frag_netmem);
struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset,
unsigned int size, gfp_t gfp)
{
return netmem_to_page(page_pool_alloc_frag_netmem(pool, offset, size,
gfp));
}
EXPORT_SYMBOL(page_pool_alloc_frag);
static void page_pool_empty_ring(struct page_pool *pool)
{
struct page *page;
netmem_ref netmem;
/* Empty recycle ring */
while ((page = ptr_ring_consume_bh(&pool->ring))) {
while ((netmem = (__force netmem_ref)ptr_ring_consume_bh(&pool->ring))) {
/* Verify the refcnt invariant of cached pages */
if (!(page_ref_count(page) == 1))
if (!(page_ref_count(netmem_to_page(netmem)) == 1))
pr_crit("%s() page_pool refcnt %d violation\n",
__func__, page_ref_count(page));
__func__, netmem_ref_count(netmem));
page_pool_return_page(pool, page);
page_pool_return_page(pool, netmem);
}
}
@ -942,7 +968,7 @@ static void __page_pool_destroy(struct page_pool *pool)
static void page_pool_empty_alloc_cache_once(struct page_pool *pool)
{
struct page *page;
netmem_ref netmem;
if (pool->destroy_cnt)
return;
@ -952,8 +978,8 @@ static void page_pool_empty_alloc_cache_once(struct page_pool *pool)
* call concurrently.
*/
while (pool->alloc.count) {
page = pool->alloc.cache[--pool->alloc.count];
page_pool_return_page(pool, page);
netmem = pool->alloc.cache[--pool->alloc.count];
page_pool_return_page(pool, netmem);
}
}
@ -1060,15 +1086,15 @@ EXPORT_SYMBOL(page_pool_destroy);
/* Caller must provide appropriate safe context, e.g. NAPI. */
void page_pool_update_nid(struct page_pool *pool, int new_nid)
{
struct page *page;
netmem_ref netmem;
trace_page_pool_update_nid(pool, new_nid);
pool->p.nid = new_nid;
/* Flush pool alloc cache, as refill will check NUMA node */
while (pool->alloc.count) {
page = pool->alloc.cache[--pool->alloc.count];
page_pool_return_page(pool, page);
netmem = pool->alloc.cache[--pool->alloc.count];
page_pool_return_page(pool, netmem);
}
}
EXPORT_SYMBOL(page_pool_update_nid);

8
net/core/skbuff.c
View File

@ -1015,8 +1015,10 @@ int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
EXPORT_SYMBOL(skb_cow_data_for_xdp);
#if IS_ENABLED(CONFIG_PAGE_POOL)
bool napi_pp_put_page(struct page *page)
bool napi_pp_put_page(netmem_ref netmem)
{
struct page *page = netmem_to_page(netmem);
page = compound_head(page);
/* page->pp_magic is OR'ed with PP_SIGNATURE after the allocation
@ -1029,7 +1031,7 @@ bool napi_pp_put_page(struct page *page)
if (unlikely(!is_pp_page(page)))
return false;
page_pool_put_full_page(page->pp, page, false);
page_pool_put_full_netmem(page->pp, page_to_netmem(page), false);
return true;
}
@ -1040,7 +1042,7 @@ static bool skb_pp_recycle(struct sk_buff *skb, void *data)
{
if (!IS_ENABLED(CONFIG_PAGE_POOL) || !skb->pp_recycle)
return false;
return napi_pp_put_page(virt_to_page(data));
return napi_pp_put_page(page_to_netmem(virt_to_page(data)));
}
/**