From patchwork Thu Oct 22 08:21:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 298691 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9945C388F7 for ; Thu, 22 Oct 2020 08:22:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B7A5223C7 for ; Thu, 22 Oct 2020 08:22:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603354946; bh=grrujud9EHPu2ij7pJxYCd0l9+KzN+YRkFGQSDx/LVk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QwswWZ33THPTaUSDk0Elqel4u+mhKzEOjuFpVdlM677SMDP49VaPvskz/gj4UMaIJ Mg5qMNuRGGhAl70DrzOTkunqvkCqADZr4tp3RPKN6c32AjPnH69KSHn2qeC6js4OPn RKrY9sZ+dqV8Kc5vx08xGNcuIBlF07k90si9MSp8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2895270AbgJVIWZ convert rfc822-to-8bit (ORCPT ); Thu, 22 Oct 2020 04:22:25 -0400 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:59074 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2443118AbgJVIWZ (ORCPT ); Thu, 22 Oct 2020 04:22:25 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-144-O96xkGQbMumUIQ-GyHKVXQ-1; Thu, 22 Oct 2020 04:22:20 -0400 X-MC-Unique: O96xkGQbMumUIQ-GyHKVXQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0AB57186DD31; Thu, 22 Oct 2020 08:22:18 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.195.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id CE75C60BFA; Thu, 22 Oct 2020 08:22:14 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Daniel Xu , Steven Rostedt , Jesper Brouer , =?utf-8?q?Toke_H=C3=B8ilan?= =?utf-8?q?d-J=C3=B8rgensen?= , Viktor Malik Subject: [RFC bpf-next 08/16] bpf: Use delayed link free in bpf_link_put Date: Thu, 22 Oct 2020 10:21:30 +0200 Message-Id: <20201022082138.2322434-9-jolsa@kernel.org> In-Reply-To: <20201022082138.2322434-1-jolsa@kernel.org> References: <20201022082138.2322434-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jolsa@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Moving bpf_link_free call into delayed processing so we don't need to wait for it when releasing the link. For example bpf_tracing_link_release could take considerable amount of time in bpf_trampoline_put function due to synchronize_rcu_tasks call. It speeds up bpftrace release time in following example: Before: Performance counter stats for './src/bpftrace -ve kfunc:__x64_sys_s* { printf("test\n"); } i:ms:10 { printf("exit\n"); exit();}' (5 runs): 3,290,457,628 cycles:k ( +- 0.27% ) 933,581,973 cycles:u ( +- 0.20% ) 50.25 +- 4.79 seconds time elapsed ( +- 9.53% ) After: Performance counter stats for './src/bpftrace -ve kfunc:__x64_sys_s* { printf("test\n"); } i:ms:10 { printf("exit\n"); exit();}' (5 runs): 2,535,458,767 cycles:k ( +- 0.55% ) 940,046,382 cycles:u ( +- 0.27% ) 33.60 +- 3.27 seconds time elapsed ( +- 9.73% ) Signed-off-by: Jiri Olsa --- kernel/bpf/syscall.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 1110ecd7d1f3..61ef29f9177d 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2346,12 +2346,8 @@ void bpf_link_put(struct bpf_link *link) if (!atomic64_dec_and_test(&link->refcnt)) return; - if (in_atomic()) { - INIT_WORK(&link->work, bpf_link_put_deferred); - schedule_work(&link->work); - } else { - bpf_link_free(link); - } + INIT_WORK(&link->work, bpf_link_put_deferred); + schedule_work(&link->work); } static int bpf_link_release(struct inode *inode, struct file *filp)