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=-6.8 required=3.0 tests=BAYES_00,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 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 744A7C433E2 for ; Wed, 2 Sep 2020 06:15:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D7F320665 for ; Wed, 2 Sep 2020 06:15:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="GUNAzZkp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726406AbgIBGPJ (ORCPT ); Wed, 2 Sep 2020 02:15:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726144AbgIBGPH (ORCPT ); Wed, 2 Sep 2020 02:15:07 -0400 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60AD4C061244; Tue, 1 Sep 2020 23:15:06 -0700 (PDT) Received: by mail-pj1-x102d.google.com with SMTP id mm21so1856125pjb.4; Tue, 01 Sep 2020 23:15:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=7UexMl4Oz9FPSyV+T67D6cz0OdUMIiPQjUqcVWaXsGQ=; b=GUNAzZkpecE92/CDBLaZgdVB3RrJt39Lo7RvumJAh+07vh239+s5SmaDRMP7Y5ivo0 qlfr4Yymf/ia4jkUiuGP7sc+l/05Z4ZRELPxP0I/x/ywlt2BsglVz8xcU+ZHS0b3Lspj 787WnOsMf1+EEfrUQE2zus+9DkjLuemMSkgeXoQpnR5k5cVhddLGQlD4I0qUJS3UOQDZ QkMXIVk/BPldPIcniCpGhDs6XVW8vc7chb72NvDqLD4GXq5vQSkuSARpHsUUnFHEJ/+A un6x/dYEfFINTo4EnAdRlkd+YdEOhjuL2/em/pU06zVh7R84FGVTEHQ0kGW2j5nEA0if RuSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=7UexMl4Oz9FPSyV+T67D6cz0OdUMIiPQjUqcVWaXsGQ=; b=BH4PST6jSoeWaIXSkFL++MfID/gY7K/JaZkQMMKQXMr1xtki+/qaTVzfiDKVJ3ZwDT Qq8w4dHVWV0RfIsrAQ6OjNdByh/9FRPDuZp6yFM6rfdfVVapIIBobixTjKllROh74CSr 4DsO/F7DZ2mcduw53ImIrIB5bZb+RNLfFq/5zqeJMe6e76ncwPUSeh8E0hFEZ9MmQlFc jBJ/zA5e3CEJ7Bve0AJB/C3m1QLB/TY64ewnNJiQqsioP8DAH9RHezTP8NkSW1MfGOfN mgi6DD4t9u8AOjfpqcCf5mul5I7AvNmE/5wzu8jQI+MT4MMhiDSIy5GVe6/X063qAHs5 vENg== X-Gm-Message-State: AOAM533ofTs5pbgwiB5c85mmDlPoyRj8llKVkcvCAbF4qsyDTDrspwhY kUpjMFSNmAeOCvxBUbuSmpo= X-Google-Smtp-Source: ABdhPJwIFwbvs0jkx65H9HyddcBDPgvXBsvrP1yzp9EI7UkwnTzcwJrx666RyFZQCC3i4RByRk/N3g== X-Received: by 2002:a17:90a:aa8a:: with SMTP id l10mr903919pjq.110.1599027302505; Tue, 01 Sep 2020 23:15:02 -0700 (PDT) Received: from localhost ([184.63.162.180]) by smtp.gmail.com with ESMTPSA id n2sm4149342pfa.182.2020.09.01.23.15.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Sep 2020 23:15:01 -0700 (PDT) Date: Tue, 01 Sep 2020 23:14:53 -0700 From: John Fastabend To: Andrii Nakryiko , bpf@vger.kernel.org, netdev@vger.kernel.org, ast@fb.com, daniel@iogearbox.net Cc: andrii.nakryiko@gmail.com, kernel-team@fb.com, Andrii Nakryiko Message-ID: <5f4f385de8cd3_5f39820863@john-XPS-13-9370.notmuch> In-Reply-To: <20200901015003.2871861-4-andriin@fb.com> References: <20200901015003.2871861-1-andriin@fb.com> <20200901015003.2871861-4-andriin@fb.com> Subject: RE: [PATCH v2 bpf-next 03/14] libbpf: support CO-RE relocations for multi-prog sections Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Andrii Nakryiko wrote: > Fix up CO-RE relocation code to handle relocations against ELF sections > containing multiple BPF programs. This requires lookup of a BPF program by its > section name and instruction index it contains. While it could have been done > as a simple loop, it could run into performance issues pretty quickly, as > number of CO-RE relocations can be quite large in real-world applications, and > each CO-RE relocation incurs BPF program look up now. So instead of simple > loop, implement a binary search by section name + insn offset. > > Signed-off-by: Andrii Nakryiko > --- > tools/lib/bpf/libbpf.c | 82 +++++++++++++++++++++++++++++++++++++----- > 1 file changed, 74 insertions(+), 8 deletions(-) > Acked-by: John Fastabend