page_pool: always add GFP_NOWARN for ATOMIC allocations

Driver authors often forget to add GFP_NOWARN for page allocation
from the datapath. This is annoying to users as OOMs are a fact
of life, and we pretty much expect network Rx to hit page allocation
failures during OOM. Make page pool add GFP_NOWARN for ATOMIC allocations
by default.

Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250912161703.361272-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index ba70569bd4b051129d3ec7a56cd3c61fd57a0b79..36a98f2bcac3b435dd3ff42ce721c75faaf97e5f 100644 (file)
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -555,6 +555,12 @@ static noinline netmem_ref __page_pool_alloc_netmems_slow(struct page_pool *pool
        netmem_ref netmem;
        int i, nr_pages;
 
+       /* Unconditionally set NOWARN if allocating from NAPI.
+        * Drivers forget to set it, and OOM reports on packet Rx are useless.
+        */
+       if ((gfp & GFP_ATOMIC) == GFP_ATOMIC)
+               gfp |= __GFP_NOWARN;
+
        /* Don't support bulk alloc for high-order pages */
        if (unlikely(pp_order))
                return page_to_netmem(__page_pool_alloc_page_order(pool, gfp));