diff mbox series

[v4,bpf-next,13/15] bpf: Prepare bpf_mem_alloc to be used by sleepable bpf programs.

Message ID 20220826024430.84565-14-alexei.starovoitov@gmail.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: BPF specific memory allocator. | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR fail PR summary
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/cc_maintainers warning 8 maintainers not CCed: john.fastabend@gmail.com jolsa@kernel.org song@kernel.org yhs@fb.com haoluo@google.com martin.lau@linux.dev kpsingh@kernel.org sdf@google.com
netdev/build_clang success Errors and warnings before: 5 this patch: 5
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5 this patch: 5
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 32 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
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bpf/vmtest-bpf-next-VM_Test-9 success Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_progs_no_alu32 on s390x with gcc
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Commit Message

Alexei Starovoitov Aug. 26, 2022, 2:44 a.m. UTC 
From: Alexei Starovoitov <ast@kernel.org>

Use call_rcu_tasks_trace() to wait for sleepable progs to finish.
Then use call_rcu() to wait for normal progs to finish
and finally do free_one() on each element when freeing objects
into global memory pool.

Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/memalloc.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index 54455a64699b..9caeeaaf9bcb 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -225,6 +225,13 @@  static void __free_rcu(struct rcu_head *head)
 	atomic_set(&c->call_rcu_in_progress, 0);
 }
 
+static void __free_rcu_tasks_trace(struct rcu_head *head)
+{
+	struct bpf_mem_cache *c = container_of(head, struct bpf_mem_cache, rcu);
+
+	call_rcu(&c->rcu, __free_rcu);
+}
+
 static void enque_to_free(struct bpf_mem_cache *c, void *obj)
 {
 	struct llist_node *llnode = obj;
@@ -250,7 +257,11 @@  static void do_call_rcu(struct bpf_mem_cache *c)
 		 * from __free_rcu() and from drain_mem_cache().
 		 */
 		__llist_add(llnode, &c->waiting_for_gp);
-	call_rcu(&c->rcu, __free_rcu);
+	/* Use call_rcu_tasks_trace() to wait for sleepable progs to finish.
+	 * Then use call_rcu() to wait for normal progs to finish
+	 * and finally do free_one() on each element.
+	 */
+	call_rcu_tasks_trace(&c->rcu, __free_rcu_tasks_trace);
 }
 
 static void free_bulk(struct bpf_mem_cache *c)
@@ -453,6 +464,7 @@  void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma)
 		/* c->waiting_for_gp list was drained, but __free_rcu might
 		 * still execute. Wait for it now before we free 'c'.
 		 */
+		rcu_barrier_tasks_trace();
 		rcu_barrier();
 		free_percpu(ma->cache);
 		ma->cache = NULL;