forked from mirrors/linux
e65a5c6edb
This patch adds a few bpf mem allocator functions which will be used in the bpf_local_storage in a later patch. bpf_mem_cache_alloc_flags(..., gfp_t flags) is added. When the flags == GFP_KERNEL, it will fallback to __alloc(..., GFP_KERNEL). bpf_local_storage knows its running context is sleepable (GFP_KERNEL) and provides a better guarantee on memory allocation. bpf_local_storage has some uncommon cases that its selem cannot be reused immediately. It handles its own rcu_head and goes through a rcu_trace gp and then free it. bpf_mem_cache_raw_free() is added for direct free purpose without leaking the LLIST_NODE_SZ internal knowledge. During free time, the 'struct bpf_mem_alloc *ma' is no longer available. However, the caller should know if it is percpu memory or not and it can call different raw_free functions. bpf_local_storage does not support percpu value, so only the non-percpu 'bpf_mem_cache_raw_free()' is added in this patch. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230322215246.1675516-2-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
37 lines
1.3 KiB
C
37 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
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#ifndef _BPF_MEM_ALLOC_H
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#define _BPF_MEM_ALLOC_H
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#include <linux/compiler_types.h>
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#include <linux/workqueue.h>
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struct bpf_mem_cache;
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struct bpf_mem_caches;
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struct bpf_mem_alloc {
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struct bpf_mem_caches __percpu *caches;
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struct bpf_mem_cache __percpu *cache;
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struct work_struct work;
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};
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/* 'size != 0' is for bpf_mem_alloc which manages fixed-size objects.
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* Alloc and free are done with bpf_mem_cache_{alloc,free}().
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*
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* 'size = 0' is for bpf_mem_alloc which manages many fixed-size objects.
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* Alloc and free are done with bpf_mem_{alloc,free}() and the size of
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* the returned object is given by the size argument of bpf_mem_alloc().
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*/
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int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu);
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void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma);
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/* kmalloc/kfree equivalent: */
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void *bpf_mem_alloc(struct bpf_mem_alloc *ma, size_t size);
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void bpf_mem_free(struct bpf_mem_alloc *ma, void *ptr);
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/* kmem_cache_alloc/free equivalent: */
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void *bpf_mem_cache_alloc(struct bpf_mem_alloc *ma);
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void bpf_mem_cache_free(struct bpf_mem_alloc *ma, void *ptr);
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void bpf_mem_cache_raw_free(void *ptr);
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void *bpf_mem_cache_alloc_flags(struct bpf_mem_alloc *ma, gfp_t flags);
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#endif /* _BPF_MEM_ALLOC_H */
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