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| author | Alexei Starovoitov <ast@kernel.org> | 2025-02-22 05:44:27 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-02-27 20:39:44 +0300 |
| commit | c9eb8102e21e8c4c6fb74d1921d99e4d43713520 (patch) | |
| tree | e236a453607f51e48c9c3910f57fae94fb5bbe15 /kernel/bpf/syscall.c | |
| parent | e8d78dbd0199a42f4e8599d768e77348f3e59741 (diff) | |
| download | linux-c9eb8102e21e8c4c6fb74d1921d99e4d43713520.tar.xz | |
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>
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 23 |
1 files changed, 20 insertions, 3 deletions
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; } |