[PATCH net-next] net: page_pool: scale alloc cache with PAGE_SIZE
From: Nimrod Oren <hidden>
Date: 2026-03-09 08:12:58
Also in:
lkml
Subsystem:
networking [general], page pool, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jesper Dangaard Brouer, Ilias Apalodimas, Linus Torvalds
The current page_pool alloc-cache size and refill values were chosen to match the NAPI budget and to leave headroom for XDP_DROP recycling. These fixed values do not scale well with large pages, as they significantly increase a given page_pool's memory footprint. Scale these values to better balance memory footprint across page sizes, while keeping behavior on 4KB-page systems unchanged. Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Signed-off-by: Nimrod Oren <redacted> --- Changes since RFC [1]: - Converted from RFC to PATCH - Scale defines instead of dynamically capping values [1] RFC: https://lore.kernel.org/20260223092410.2149014-1-noren@nvidia.com/ (local) --- include/net/page_pool/types.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 0d453484a585..08ffa766c26d 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h@@ -44,6 +44,8 @@ * use-case. The NAPI budget is 64 packets. After a NAPI poll the RX * ring is usually refilled and the max consumed elements will be 64, * thus a natural max size of objects needed in the cache. + * The refill watermark is set to 64 for 4KB pages, + * and scales to balance its size in bytes across page sizes. * * Keeping room for more objects, is due to XDP_DROP use-case. As * XDP_DROP allows the opportunity to recycle objects directly into
@@ -51,8 +53,15 @@ * cache is already full (or partly full) then the XDP_DROP recycles * would have to take a slower code path. */ -#define PP_ALLOC_CACHE_SIZE 128 +#if PAGE_SIZE >= SZ_64K +#define PP_ALLOC_CACHE_REFILL 4 +#elif PAGE_SIZE >= SZ_16K +#define PP_ALLOC_CACHE_REFILL 16 +#else #define PP_ALLOC_CACHE_REFILL 64 +#endif + +#define PP_ALLOC_CACHE_SIZE (PP_ALLOC_CACHE_REFILL * 2) struct pp_alloc_cache { u32 count; netmem_ref cache[PP_ALLOC_CACHE_SIZE];
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2.45.0