[PATCH net-next v4 2/5] page_frag: unify gfp bits for order 3 page allocation
From: Yunsheng Lin <hidden>
Date: 2024-01-30 11:38:02
Also in:
kvm, linux-mm, lkml, virtualization
Subsystem:
memory management, memory management - page allocator, networking [general], networking [sockets], the rest, virtio host (vhost) · Maintainers:
Andrew Morton, Vlastimil Babka, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Currently there seems to be three page frag implementions which all try to allocate order 3 page, if that fails, it then fail back to allocate order 0 page, and each of them all allow order 3 page allocation to fail under certain condition by using specific gfp bits. The gfp bits for order 3 page allocation are different between different implementation, __GFP_NOMEMALLOC is or'd to forbid access to emergency reserves memory for __page_frag_cache_refill(), but it is not or'd in other implementions, __GFP_DIRECT_RECLAIM is masked off to avoid direct reclaim in skb_page_frag_refill(), but it is not masked off in __page_frag_cache_refill(). This patch unifies the gfp bits used between different implementions by or'ing __GFP_NOMEMALLOC and masking off __GFP_DIRECT_RECLAIM for order 3 page allocation to avoid possible pressure for mm. Signed-off-by: Yunsheng Lin <redacted> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> CC: Alexander Duyck <redacted> --- drivers/vhost/net.c | 2 +- mm/page_alloc.c | 4 ++-- net/core/sock.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index f2ed7167c848..e574e21cc0ca 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c@@ -670,7 +670,7 @@ static bool vhost_net_page_frag_refill(struct vhost_net *net, unsigned int sz, /* Avoid direct reclaim but allow kswapd to wake */ pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | __GFP_NOWARN | - __GFP_NORETRY, + __GFP_NORETRY | __GFP_NOMEMALLOC, SKB_FRAG_PAGE_ORDER); if (likely(pfrag->page)) { pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c0f7e67c4250..636145c29f70 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c@@ -4685,8 +4685,8 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, gfp_t gfp = gfp_mask; #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) - gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY | - __GFP_NOMEMALLOC; + gfp_mask = (gfp_mask & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | + __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC; page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, PAGE_FRAG_CACHE_MAX_ORDER); nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
diff --git a/net/core/sock.c b/net/core/sock.c
index 88bf810394a5..8289a3d8c375 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c@@ -2919,7 +2919,7 @@ bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp) /* Avoid direct reclaim but allow kswapd to wake */ pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | __GFP_NOWARN | - __GFP_NORETRY, + __GFP_NORETRY | __GFP_NOMEMALLOC, SKB_FRAG_PAGE_ORDER); if (likely(pfrag->page)) { pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
--
2.33.0