diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2025-02-21 18:44:27 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-02-27 09:39:44 -0800 |
| commit | c9eb8102e21e8c4c6fb74d1921d99e4d43713520 (patch) | |
| tree | e236a453607f51e48c9c3910f57fae94fb5bbe15 | |
| parent | e8d78dbd0199a42f4e8599d768e77348f3e59741 (diff) | |
bpf: Use try_alloc_pages() to allocate pages for bpf needs.
Use try_alloc_pages() and free_pages_nolock() for BPF needs
when context doesn't allow using normal alloc_pages.
This is a prerequisite for further work.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20250222024427.30294-7-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | include/linux/bpf.h | 2 | ||||
| -rw-r--r-- | kernel/bpf/arena.c | 5 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 23 |
3 files changed, 23 insertions, 7 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f3f50e29d639..e1838a341817 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2348,7 +2348,7 @@ int generic_map_delete_batch(struct bpf_map *map, struct bpf_map *bpf_map_get_curr_or_next(u32 *id); struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id); -int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid, +int bpf_map_alloc_pages(const struct bpf_map *map, int nid, unsigned long nr_pages, struct page **page_array); #ifdef CONFIG_MEMCG void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c index 870aeb51d70a..aa43d6c34c46 100644 --- a/kernel/bpf/arena.c +++ b/kernel/bpf/arena.c @@ -287,7 +287,7 @@ static vm_fault_t arena_vm_fault(struct vm_fault *vmf) return VM_FAULT_SIGSEGV; /* Account into memcg of the process that created bpf_arena */ - ret = bpf_map_alloc_pages(map, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE, 1, &page); + ret = bpf_map_alloc_pages(map, NUMA_NO_NODE, 1, &page); if (ret) { range_tree_set(&arena->rt, vmf->pgoff, 1); return VM_FAULT_SIGSEGV; @@ -465,8 +465,7 @@ static long arena_alloc_pages(struct bpf_arena *arena, long uaddr, long page_cnt if (ret) goto out_free_pages; - ret = bpf_map_alloc_pages(&arena->map, GFP_KERNEL | __GFP_ZERO, - node_id, page_cnt, pages); + ret = bpf_map_alloc_pages(&arena->map, node_id, page_cnt, pages); if (ret) goto out; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index c420edbfb7c8..a7af8d0185d0 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -569,7 +569,24 @@ static void bpf_map_release_memcg(struct bpf_map *map) } #endif -int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid, +static bool can_alloc_pages(void) +{ + return preempt_count() == 0 && !irqs_disabled() && + !IS_ENABLED(CONFIG_PREEMPT_RT); +} + +static struct page *__bpf_alloc_page(int nid) +{ + if (!can_alloc_pages()) + return try_alloc_pages(nid, 0); + + return alloc_pages_node(nid, + GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT + | __GFP_NOWARN, + 0); +} + +int bpf_map_alloc_pages(const struct bpf_map *map, int nid, unsigned long nr_pages, struct page **pages) { unsigned long i, j; @@ -582,14 +599,14 @@ int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid, old_memcg = set_active_memcg(memcg); #endif for (i = 0; i < nr_pages; i++) { - pg = alloc_pages_node(nid, gfp | __GFP_ACCOUNT, 0); + pg = __bpf_alloc_page(nid); if (pg) { pages[i] = pg; continue; } for (j = 0; j < i; j++) - __free_page(pages[j]); + free_pages_nolock(pages[j], 0); ret = -ENOMEM; break; } |