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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03BD9C433F5 for ; Tue, 24 May 2022 12:10:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235126AbiEXMKX (ORCPT ); Tue, 24 May 2022 08:10:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233396AbiEXMKW (ORCPT ); Tue, 24 May 2022 08:10:22 -0400 Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [IPv6:2a00:1450:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C641C68FAA for ; Tue, 24 May 2022 05:10:21 -0700 (PDT) Received: by mail-ed1-x52f.google.com with SMTP id ee42so2148281edb.1 for ; Tue, 24 May 2022 05:10:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=NqjBlbfOFsl5TUBF1M2MxoL6zErRxcfavrGqAXdBsRk=; b=DBOE0PffwqbypJOoPsKdgQ9N+Py5FHvbrq32Lci5rLmCI/6OKxgOSz77CptaCi9Y9a 55cC9VTI6oUXo/dX7dOI2SOWO6t7dS+k2po2lvxqjC9xLVwkKraKTnIRIX3bMasTDtku UYWz74aOt9Fehz5EH0cXOj5ryeFLM7hiSXMvL/ISq1/RHwbuJLlh/UJRTEcGJUm2biM0 lVQY9Pp59GMry4pT/WHgj3quWSXbAmqv8THtwpMcSknIbrsCvl8L5nsVkwhH1vk1MWMr pELSBGhUCipzKtK5c66+i1+etGSYCirw4uCiC074NyXWC9ZtUCx/1pxMev5CSnWaYCaJ Uf8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=NqjBlbfOFsl5TUBF1M2MxoL6zErRxcfavrGqAXdBsRk=; b=uhbYV5YE75akgm0mlaLBtZbn+DtH9nlesVOmmj5Sdw9UgaRwt+RXw8xtAVtPuNjhDZ Hvl2W8X3fPi6Qd4v58EiwH9QnN3f2y8a6yn55OoSCRqZqeJwaaYaL8yd7DbUmKnR/1ws abiTx2fKIKHxkdZYyyU3FibEbjPmBi4Ma+NQTxw05sFeQSrtejGuQlee4p5Sa6iCubmy Wl+9jmeUoIgu5V3dbObjGR5aiGC31PkRSwGDiIlQ2v1LKUJI1EWQ2kasfYOqopEh8ASP NUzCti0X9yQ7euHj5GCEAK9J/e1H2i6kdHW1KTEUQqmQkvUcd/IVDrFKm9MVOsYtf1b/ KoeA== X-Gm-Message-State: AOAM531D2hNmMsXglKgC5oK06gsPh02j0wFkBIdRj+wIV8giGLFzpNem DpJQNfiP/GuxOEQF46Nzuhw= X-Google-Smtp-Source: ABdhPJy9hkllC5OUf9ipZ+CqDjAPsuieoQbOlhmFtLJ/EDj8a6XRVWNOjyu6x3sHVs/zpPYb+M6dLA== X-Received: by 2002:a05:6402:424b:b0:42b:3871:75fa with SMTP id g11-20020a056402424b00b0042b387175famr17976424edb.92.1653394220270; Tue, 24 May 2022 05:10:20 -0700 (PDT) Received: from krava (net-93-147-242-253.cust.vodafonedsl.it. [93.147.242.253]) by smtp.gmail.com with ESMTPSA id o18-20020aa7d3d2000000b0042a96c77e9esm9253067edr.91.2022.05.24.05.10.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 May 2022 05:10:19 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Tue, 24 May 2022 14:10:17 +0200 To: Thomas Richter Cc: "linux-perf-use." , Arnaldo Carvalho de Melo , Jiri Olsa , Sumanth Korikkar , Heiko Carstens , vasily Gorbik , Ian Rogers , Ilya Leoshkevich , Sven Schnelle Subject: Re: perf test case 40 LLVM search and compile runs endless (eBPF linkage issue) Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org On Mon, May 23, 2022 at 01:09:51PM +0200, Jiri Olsa wrote: > On Mon, May 23, 2022 at 12:52:06PM +0200, Thomas Richter wrote: > > On s390 the test case 40 'LLVM search and compile' runs for ever: > > > > # date; timeout 30s perf test -F 40; date > > Mon May 23 12:35:48 PM CEST 2022 > > 40: LLVM search and compile : > > 40.1: Basic BPF llvm compile : > > Mon May 23 12:36:18 PM CEST 2022 > > # > > > > Investigation by Ilya Leoshkevich revealed: > > On s390 we hit an endless loop where bpf_object__next_program and bpf_program__next > > infinitely call each other. We tracked this down to ld.so preferring the perf's > > bpf_object__next_program weak copy over the libbpf's strong one. > > > > This is introduced with commit 2a4898fc264a ("perf tools: Add more weak libbpf functions") > > > > Also see discussion in > > https://lore.kernel.org/lkml/YY%2FAR2Dcaws0BAE9@kernel.org/ > > > > How can this be fixed asap? Thanks a lot. > > I was just suggesting to remove that: > https://lore.kernel.org/bpf/Yos8hq3NmBwemoJw@krava/T/#mda8abccbf475b99d25abe5498a5df1af2da82ee8 > > it's no longer needed and can cause problem apparently after discussing with Arnaldo we decided to go for another fix, could you please try this branch: git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git perf/weak thanks, jirka