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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 61B7AC3A5A7 for ; Wed, 4 Sep 2019 15:37:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3336722CF7 for ; Wed, 4 Sep 2019 15:37:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Tu8rI1Ku" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731420AbfIDPhg (ORCPT ); Wed, 4 Sep 2019 11:37:36 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:34461 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731360AbfIDPhf (ORCPT ); Wed, 4 Sep 2019 11:37:35 -0400 Received: by mail-lf1-f65.google.com with SMTP id z21so16344603lfe.1 for ; Wed, 04 Sep 2019 08:37:34 -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=+Ye9YWn7/omSBzztqXrART/0Y1Y+95q9ms0+sQVUL6s=; b=Tu8rI1Kuamg9Y649dTRy6XriM1ep1WSj4qoLBaUx7TjgzUtiI/VEEby+la8mEBB+PG Xob6GPod8Ha5e3Ql6YmSLrIt0VPwwW5obmWhP4XmSFp6kBz55UhtazRKHVcLIhVxZ//7 1BPVanhCbQj82kRCTkiF0rX2mWpspkpCTlkh/dXJa0rrJBOulWhJ6SKVbtcJo2Bz8wBs SW0JMWKmqtd74JWL921q4RgUWsjLjeTu/4LlLiIjKU+vdznmtuaGqFQe8FYG2sYFDDHF o4sug+VflmpMgVuiPzwZZ3/hMP9mTRTeuLpolRv5BEMEf7pbBoz9okuIWD5yjYdqyjiB s/ww== 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=+Ye9YWn7/omSBzztqXrART/0Y1Y+95q9ms0+sQVUL6s=; b=C3410y6FVNdCKaWsZno9PYaIuJ6Hs+7m+8i177KEwK+MdXoqFMCBSojoJLneNIrQpa Hb4TySesnxecT6eNnBA8m9Am29sL26VTtiSOwo8BKIWMHZ9bkYpho+LtSPAA3fvzLme+ xpNq37jJtEVFeKCCR+eq3lD3FktnwkiFh1rBf8oWQhGtZZKluwbCAqx3+H/XJKmJwE2t 6jQr79DtWKxrrksIytESnVaxmWErDXpLvB00mL9OUm3ZWRKgc+2uE1waGrxGkGyEbNkh ppZqiK3N2nlTuFwIHcm/L1/LFmmhM4EKpJr0lPumDuaKD3hUTwKl1l5qmVzkbGsH0mVx UqJQ== X-Gm-Message-State: APjAAAWCh4QQd6rvlcRu53bM9OTY7pFleS9JzyU3t0zYan3qLehtk3cc 0nahkmi+vdBuNA1pUIxSLBljGWRpNh6w6lkAZIE= X-Google-Smtp-Source: APXvYqxVMjCIJsj8a0ahcD1Ttkk6UogqOJ9pBT3H31FXsfLdy0wTZNjRvPRuriAaSVEmYEHYFc/9ssoPjOp9pmWdrC8= X-Received: by 2002:ac2:558a:: with SMTP id v10mr3132487lfg.162.1567611453657; Wed, 04 Sep 2019 08:37:33 -0700 (PDT) MIME-Version: 1.0 References: <20190903154340.860299-1-rkrcmar@redhat.com> <20190903154340.860299-3-rkrcmar@redhat.com> <20190904042310.GA159235@google.com> <20190904081448.GZ2349@hirez.programming.kicks-ass.net> <20190904131154.GF144846@google.com> <20190904153330.GI240514@google.com> In-Reply-To: <20190904153330.GI240514@google.com> From: Alexei Starovoitov Date: Wed, 4 Sep 2019 08:37:22 -0700 Message-ID: Subject: Re: [PATCH 2/2] sched/debug: add sched_update_nr_running tracepoint To: Joel Fernandes Cc: Peter Zijlstra , Valentin Schneider , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , LKML , Ingo Molnar , Thomas Gleixner , Borislav Petkov , Dave Hansen , Steven Rostedt , "H. Peter Anvin" , Andy Lutomirski , =?UTF-8?Q?Jirka_Hladk=C3=BD?= , =?UTF-8?B?SmnFmcOtIFZvesOhcg==?= , X86 ML , Qais Yousef Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 4, 2019 at 8:33 AM Joel Fernandes wrote: > > On Wed, Sep 04, 2019 at 08:26:52AM -0700, Alexei Starovoitov wrote: > > On Wed, Sep 4, 2019 at 6:14 AM Joel Fernandes wrote: > > > > > > True. However, for kprobes-based BPF program - it does check for kernel > > > version to ensure that the BPF program is built against the right kernel > > > version (in order to ensure the program is built against the right set of > > > kernel headers). If it is not, then BPF refuses to load the program. > > > > This is not true anymore. Users found few ways to workaround that check > > in practice. It became useless and it was deleted some time ago. > > Wow, Ok! Interesting! the other part of your email says about kernel header requirement. This is not true any more as well :) BTF relocations are already supported by the kernel, llvm, libbpf, bpftool, pahole. We'll be posting sample code soon.