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Date: Fri, 19 Aug 2022 14:42:30 -0700 Message-Id: <20220819214232.18784-14-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220819214232.18784-1-alexei.starovoitov@gmail.com> References: <20220819214232.18784-1-alexei.starovoitov@gmail.com> MIME-Version: 1.0 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660945403; a=rsa-sha256; cv=none; b=0OHrkzipw0uO9JxBNH4JDvMwPjpYxfW1Zycifd0joeTUmoD8ig7NRqWqa3xCaf5LccvYnn zJFtLt+fJ/AfX81l9lePPRj5f5HWHFcVZZZ8dT2WGETvi2M/Unf45x9lun5bEiDkSwjyrm s2aWRTK+kPDX3yKuB/iAN77e+wO53Ik= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=AVNDNwVR; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf02.hostedemail.com: domain of alexei.starovoitov@gmail.com designates 209.85.216.54 as permitted sender) smtp.mailfrom=alexei.starovoitov@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660945403; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5M011h9hGg1xDHL/wlpIOyvMja4lICeITJBWcCRlji4=; b=6PEKTgTgFoNc6YnTelUTBYWLqy1F+2FfHMXil1WenLweiE56REtzCRlF5tz1zRhOFEDQzf mpKxkPi23dK6cuA8T+f8qdsUs/FgL/jiZhD4AnL52IXB7L3H3HkSn8qgSFTn9c8G4Wagsk NE421RGUaskf+9ovDRmLa43AWr9jG1M= X-Stat-Signature: awzmokr8d3nrcrj35p87csoha5cpzgyp X-Rspamd-Queue-Id: 964AC8008B Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=AVNDNwVR; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf02.hostedemail.com: domain of alexei.starovoitov@gmail.com designates 209.85.216.54 as permitted sender) smtp.mailfrom=alexei.starovoitov@gmail.com X-Rspamd-Server: rspam03 X-Rspam-User: X-HE-Tag: 1660945403-689582 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000076, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Alexei Starovoitov 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. Signed-off-by: Alexei Starovoitov --- kernel/bpf/memalloc.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index 9e5ad7dc4dc7..d34383dc12d9 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -224,6 +224,13 @@ 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; @@ -249,7 +256,11 @@ 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) @@ -452,6 +463,7 @@ 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;