From d65a1906b31246492449eafe9cace188cb59e26c Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Fri, 21 Jan 2022 11:09:48 +0100 Subject: net: xdp: add xdp_update_skb_shared_info utility routine Introduce xdp_update_skb_shared_info routine to update frags array metadata in skb_shared_info data structure converting to a skb from a xdp_buff or xdp_frame. According to the current skb_shared_info architecture in xdp_frame/xdp_buff and to the xdp frags support, there is no need to run skb_add_rx_frag() and reset frags array converting the buffer to a skb since the frag array will be in the same position for xdp_buff/xdp_frame and for the skb, we just need to update memory metadata. Introduce XDP_FLAGS_PF_MEMALLOC flag in xdp_buff_flags in order to mark the xdp_buff or xdp_frame as under memory-pressure if pages of the frags array are under memory pressure. Doing so we can avoid looping over all fragments in xdp_update_skb_shared_info routine. The driver is expected to set the flag constructing the xdp_buffer using xdp_buff_set_frag_pfmemalloc utility routine. Rely on xdp_update_skb_shared_info in __xdp_build_skb_from_frame routine converting the non-linear xdp_frame to a skb after performing a XDP_REDIRECT. Acked-by: Toke Hoiland-Jorgensen Acked-by: John Fastabend Acked-by: Jesper Dangaard Brouer Signed-off-by: Lorenzo Bianconi Link: https://lore.kernel.org/r/bfd23fb8a8d7438724f7819c567cdf99ffd6226f.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov --- include/net/xdp.h | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) (limited to 'include/net') diff --git a/include/net/xdp.h b/include/net/xdp.h index 485e9495a690..1f8641ec658e 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -67,7 +67,10 @@ struct xdp_txq_info { }; enum xdp_buff_flags { - XDP_FLAGS_HAS_FRAGS = BIT(0), /* non-linear xdp buff */ + XDP_FLAGS_HAS_FRAGS = BIT(0), /* non-linear xdp buff */ + XDP_FLAGS_FRAGS_PF_MEMALLOC = BIT(1), /* xdp paged memory is under + * pressure + */ }; struct xdp_buff { @@ -96,6 +99,16 @@ static __always_inline void xdp_buff_clear_frags_flag(struct xdp_buff *xdp) xdp->flags &= ~XDP_FLAGS_HAS_FRAGS; } +static __always_inline bool xdp_buff_is_frag_pfmemalloc(struct xdp_buff *xdp) +{ + return !!(xdp->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC); +} + +static __always_inline void xdp_buff_set_frag_pfmemalloc(struct xdp_buff *xdp) +{ + xdp->flags |= XDP_FLAGS_FRAGS_PF_MEMALLOC; +} + static __always_inline void xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq) { @@ -151,6 +164,11 @@ static __always_inline bool xdp_frame_has_frags(struct xdp_frame *frame) return !!(frame->flags & XDP_FLAGS_HAS_FRAGS); } +static __always_inline bool xdp_frame_is_frag_pfmemalloc(struct xdp_frame *frame) +{ + return !!(frame->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC); +} + #define XDP_BULK_QUEUE_SIZE 16 struct xdp_frame_bulk { int count; @@ -186,6 +204,19 @@ static inline void xdp_scrub_frame(struct xdp_frame *frame) frame->dev_rx = NULL; } +static inline void +xdp_update_skb_shared_info(struct sk_buff *skb, u8 nr_frags, + unsigned int size, unsigned int truesize, + bool pfmemalloc) +{ + skb_shinfo(skb)->nr_frags = nr_frags; + + skb->len += size; + skb->data_len += size; + skb->truesize += truesize; + skb->pfmemalloc |= pfmemalloc; +} + /* Avoids inlining WARN macro in fast-path */ void xdp_warn(const char *msg, const char *func, const int line); #define XDP_WARN(msg) xdp_warn(msg, __func__, __LINE__) -- cgit v1.2.3