From mboxrd@z Thu Jan 1 00:00:00 1970 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=-4.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 3B50DC433DF for ; Tue, 30 Jun 2020 00:58:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1475F20781 for ; Tue, 30 Jun 2020 00:58:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AGCzq5Sc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726226AbgF3A6u (ORCPT ); Mon, 29 Jun 2020 20:58:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41720 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726175AbgF3A6u (ORCPT ); Mon, 29 Jun 2020 20:58:50 -0400 Received: from mail-qt1-x844.google.com (mail-qt1-x844.google.com [IPv6:2607:f8b0:4864:20::844]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3804DC061755; Mon, 29 Jun 2020 17:58:50 -0700 (PDT) Received: by mail-qt1-x844.google.com with SMTP id h23so14446945qtr.0; Mon, 29 Jun 2020 17:58:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=k8JPo/MRdDtQmsz/fwYcyAAt5f70n0S8x1+bnn70EMc=; b=AGCzq5ScGJKEZa0pAhrXN+4oRqcY/tDqrJNThwziEDxbIwTKX895Gmk36T/vOl77NQ F/Qk0MOlcMge8TzVAwmu3AkJJnWTyK3ikJtNGZD0c5i1WwYkBKyCFSpgAES/LFfbn+tZ jlLq1gxqBcgbS0jG41BTOZHc86faMjr/7rQi+TiWx4p4QRE74HqzZpX2B3dn62ndEBf/ Hjjg96cPwDFItSsIRigYdUhTX2WmJJM362yfXfgJ66u6UvbHPDFpx/Q5OWC/w/WO6eXO yfJcoVYQQoFPUKaJFVj9BPpvmOUVRb0AsnBVPnvZT/jmAtJJ3m90tDMFySKKnUVv/fcq gDXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=k8JPo/MRdDtQmsz/fwYcyAAt5f70n0S8x1+bnn70EMc=; b=BvFj9TWs+I64tu7/0tZqzoho4blxyRmuFd4vBvVDJyuacmbEYgja3f1xvSYnbSY9zM Wab2LehpafRI/hg+uoa6jPtVQwj9flXGSCR5izQEjUFSR5NdN0i8OjGoATPcFkrZQJ7Q VlKu1kdmOSlM6i9yF4MHrDB6c+W8WQtWkDlu7miG4HarQfQqfgYBXiA40kVDiM3zDUPi eg69x6rUEmdeSeWW3Q8NyxH32O9Yir4WG1pEtQzwVpIQ8AEeB5zAxQ1u/xzWLnsmdI8v iwhEU9/lYVXAR2AF3z0xVnbBiGI/QidUH36utHnh5enxNSIcyzh8qpu0yOZZIwHmrZXl 2Wmg== X-Gm-Message-State: AOAM532ZyLjyQcNA4yWYBSiEjwZ8n0gvq7drcVT2sLwrYpgmsL3VrJhY Hra3R1PU4+AVgw4LVvIJERCDHAMLnk0Y4B15D/B7g6UT X-Google-Smtp-Source: ABdhPJyj2tlK4BHxtQNdgkkHACBQbL8CsdI8VFvbVoDT0vScG2ZadtRPa8Rf9zeoXSwgXMl/drqX2Uhtm6rPQz7jTrs= X-Received: by 2002:ac8:1991:: with SMTP id u17mr17805577qtj.93.1593478729427; Mon, 29 Jun 2020 17:58:49 -0700 (PDT) MIME-Version: 1.0 References: <20200630003441.42616-1-alexei.starovoitov@gmail.com> <20200630003441.42616-2-alexei.starovoitov@gmail.com> In-Reply-To: <20200630003441.42616-2-alexei.starovoitov@gmail.com> From: Andrii Nakryiko Date: Mon, 29 Jun 2020 17:58:38 -0700 Message-ID: Subject: Re: [PATCH v4 bpf-next 1/5] bpf: Remove redundant synchronize_rcu. To: Alexei Starovoitov Cc: "David S. Miller" , Daniel Borkmann , "Paul E . McKenney" , Networking , bpf , Kernel Team Content-Type: text/plain; charset="UTF-8" Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Mon, Jun 29, 2020 at 5:35 PM Alexei Starovoitov wrote: > > From: Alexei Starovoitov > > bpf_free_used_maps() or close(map_fd) will trigger map_free callback. > bpf_free_used_maps() is called after bpf prog is no longer executing: > bpf_prog_put->call_rcu->bpf_prog_free->bpf_free_used_maps. > Hence there is no need to call synchronize_rcu() to protect map elements. > > Signed-off-by: Alexei Starovoitov > --- Seems correct. And nice that maps don't have to care about this anymore. Acked-by: Andrii Nakryiko > kernel/bpf/arraymap.c | 9 --------- > kernel/bpf/hashtab.c | 8 +++----- > kernel/bpf/lpm_trie.c | 5 ----- > kernel/bpf/queue_stack_maps.c | 7 ------- > kernel/bpf/reuseport_array.c | 2 -- > kernel/bpf/ringbuf.c | 7 ------- > kernel/bpf/stackmap.c | 3 --- > 7 files changed, 3 insertions(+), 38 deletions(-) >