From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- include/net/dst_ops.h | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 include/net/dst_ops.h (limited to 'include/net/dst_ops.h') diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h new file mode 100644 index 000000000..3a9001a04 --- /dev/null +++ b/include/net/dst_ops.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_DST_OPS_H +#define _NET_DST_OPS_H +#include +#include +#include + +struct dst_entry; +struct kmem_cachep; +struct net_device; +struct sk_buff; +struct sock; +struct net; + +struct dst_ops { + unsigned short family; + unsigned int gc_thresh; + + void (*gc)(struct dst_ops *ops); + struct dst_entry * (*check)(struct dst_entry *, __u32 cookie); + unsigned int (*default_advmss)(const struct dst_entry *); + unsigned int (*mtu)(const struct dst_entry *); + u32 * (*cow_metrics)(struct dst_entry *, unsigned long); + void (*destroy)(struct dst_entry *); + void (*ifdown)(struct dst_entry *, + struct net_device *dev); + void (*negative_advice)(struct sock *sk, struct dst_entry *); + void (*link_failure)(struct sk_buff *); + void (*update_pmtu)(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu, + bool confirm_neigh); + void (*redirect)(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb); + int (*local_out)(struct net *net, struct sock *sk, struct sk_buff *skb); + struct neighbour * (*neigh_lookup)(const struct dst_entry *dst, + struct sk_buff *skb, + const void *daddr); + void (*confirm_neigh)(const struct dst_entry *dst, + const void *daddr); + + struct kmem_cache *kmem_cachep; + + struct percpu_counter pcpuc_entries ____cacheline_aligned_in_smp; +}; + +static inline int dst_entries_get_fast(struct dst_ops *dst) +{ + return percpu_counter_read_positive(&dst->pcpuc_entries); +} + +static inline int dst_entries_get_slow(struct dst_ops *dst) +{ + return percpu_counter_sum_positive(&dst->pcpuc_entries); +} + +#define DST_PERCPU_COUNTER_BATCH 32 +static inline void dst_entries_add(struct dst_ops *dst, int val) +{ + percpu_counter_add_batch(&dst->pcpuc_entries, val, + DST_PERCPU_COUNTER_BATCH); +} + +static inline int dst_entries_init(struct dst_ops *dst) +{ + return percpu_counter_init(&dst->pcpuc_entries, 0, GFP_KERNEL); +} + +static inline void dst_entries_destroy(struct dst_ops *dst) +{ + percpu_counter_destroy(&dst->pcpuc_entries); +} + +#endif -- cgit v1.3.1