Commit cd3c9316 authored by Toke Høiland-Jørgensen's avatar Toke Høiland-Jørgensen Committed by Jakub Kicinski
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page_pool: Move pp_magic check into helper functions 



Since we are about to stash some more information into the pp_magic
field, let's move the magic signature checks into a pair of helper
functions so it can be changed in one place.

Reviewed-by: default avatarMina Almasry <almasrymina@google.com>
Tested-by: default avatarYonglong Liu <liuyonglong@huawei.com>
Acked-by: default avatarJesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: default avatarIlias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409-page-pool-track-dma-v9-1-6a9ef2e0cba8@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 452446f8

drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c

+2 −2
Original line number Diff line number Diff line
@@ -707,8 +707,8 @@ static void mlx5e_free_xdpsq_desc(struct mlx5e_xdpsq *sq, 
				xdpi = mlx5e_xdpi_fifo_pop(xdpi_fifo);

				page = xdpi.page.page;



				/* No need to check ((page->pp_magic & ~0x3UL) == PP_SIGNATURE)

				 * as we know this is a page_pool page.

				/* No need to check page_pool_page_is_pp() as we

				 * know this is a page_pool page.

				 */

				page_pool_recycle_direct(page->pp, page);

			} while (++n < num);

include/linux/mm.h

+20 −0
Original line number Diff line number Diff line
@@ -4248,4 +4248,24 @@ int arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status); 
#define VM_SEALED_SYSMAP	VM_NONE

#endif



/* Mask used for checking in page_pool_page_is_pp() below. page->pp_magic is

 * OR'ed with PP_SIGNATURE after the allocation in order to preserve bit 0 for

 * the head page of compound page and bit 1 for pfmemalloc page.

 * page_is_pfmemalloc() is checked in __page_pool_put_page() to avoid recycling

 * the pfmemalloc page.

 */

#define PP_MAGIC_MASK ~0x3UL



#ifdef CONFIG_PAGE_POOL

static inline bool page_pool_page_is_pp(struct page *page)

{

	return (page->pp_magic & PP_MAGIC_MASK) == PP_SIGNATURE;

}

#else

static inline bool page_pool_page_is_pp(struct page *page)

{

	return false;

}

#endif



#endif /* _LINUX_MM_H */

mm/page_alloc.c

+2 −6
Original line number Diff line number Diff line
@@ -897,9 +897,7 @@ static inline bool page_expected_state(struct page *page, 
#ifdef CONFIG_MEMCG

			page->memcg_data |

#endif

#ifdef CONFIG_PAGE_POOL

			((page->pp_magic & ~0x3UL) == PP_SIGNATURE) |

#endif

			page_pool_page_is_pp(page) |

			(page->flags & check_flags)))

		return false;
@@ -926,10 +924,8 @@ static const char *page_bad_reason(struct page *page, unsigned long flags) 
	if (unlikely(page->memcg_data))

		bad_reason = "page still charged to cgroup";

#endif

#ifdef CONFIG_PAGE_POOL

	if (unlikely((page->pp_magic & ~0x3UL) == PP_SIGNATURE))

	if (unlikely(page_pool_page_is_pp(page)))

		bad_reason = "page_pool leak";

#endif

	return bad_reason;

}

net/core/netmem_priv.h

+5 −0
Original line number Diff line number Diff line
@@ -18,6 +18,11 @@ static inline void netmem_clear_pp_magic(netmem_ref netmem) 
	__netmem_clear_lsb(netmem)->pp_magic = 0;

}



static inline bool netmem_is_pp(netmem_ref netmem)

{

	return (netmem_get_pp_magic(netmem) & PP_MAGIC_MASK) == PP_SIGNATURE;

}



static inline void netmem_set_pp(netmem_ref netmem, struct page_pool *pool)

{

	__netmem_clear_lsb(netmem)->pp = pool;

net/core/skbuff.c

+2 −14
Original line number Diff line number Diff line
@@ -893,11 +893,6 @@ static void skb_clone_fraglist(struct sk_buff *skb) 
		skb_get(list);

}



static bool is_pp_netmem(netmem_ref netmem)

{

	return (netmem_get_pp_magic(netmem) & ~0x3UL) == PP_SIGNATURE;

}



int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,

		    unsigned int headroom)

{
@@ -995,14 +990,7 @@ bool napi_pp_put_page(netmem_ref netmem) 
{

	netmem = netmem_compound_head(netmem);



	/* page->pp_magic is OR'ed with PP_SIGNATURE after the allocation

	 * in order to preserve any existing bits, such as bit 0 for the

	 * head page of compound page and bit 1 for pfmemalloc page, so

	 * mask those bits for freeing side when doing below checking,

	 * and page_is_pfmemalloc() is checked in __page_pool_put_page()

	 * to avoid recycling the pfmemalloc page.

	 */

	if (unlikely(!is_pp_netmem(netmem)))

	if (unlikely(!netmem_is_pp(netmem)))

		return false;



	page_pool_put_full_netmem(netmem_get_pp(netmem), netmem, false);
@@ -1042,7 +1030,7 @@ static int skb_pp_frag_ref(struct sk_buff *skb) 


	for (i = 0; i < shinfo->nr_frags; i++) {

		head_netmem = netmem_compound_head(shinfo->frags[i].netmem);

		if (likely(is_pp_netmem(head_netmem)))

		if (likely(netmem_is_pp(head_netmem)))

			page_pool_ref_netmem(head_netmem);

		else

			page_ref_inc(netmem_to_page(head_netmem));