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 46600C433EF for ; Tue, 24 May 2022 14:33:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232632AbiEXOdn (ORCPT ); Tue, 24 May 2022 10:33:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232272AbiEXOdm (ORCPT ); Tue, 24 May 2022 10:33:42 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89E0166F84 for ; Tue, 24 May 2022 07:33:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 2EE3FB818F7 for ; Tue, 24 May 2022 14:33:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE08FC385AA; Tue, 24 May 2022 14:33:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653402818; bh=uJe7035b21o5k3OU08seVvA/khYOdy/5WhxDrU94Yhs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=T1X7lEiZ+5+Ytk6TWSqOdCZIe+ByLgMFwwY05w1QUQm5oI3nPLvGRlEn4R9/N/Eex ggJkKls25fswtNZAD+YCCKjpkRQT7R/YHlmhKUKr8EZwh1R9kS4/hbZNdRToygoRCO WKGbpIucDSnjQBaJYyj4TZUZJ7tQGf6R2eJMz+c+6sp9Gq9v4yGieLHd3nyS2uVxtK OUphRla9UWf1aBqxuTcbaf7AMFjA8ANYjeIzY896c9RGHHfLK9oxILZaQbjCa4KAtk 1YJDbL2wR1+j5mDNfkw9jjCWP7oTfuorRiRRX3I5fnqdNCGWdpImpb1j4jOQ+mhV/L HqJH92iFhPg/w== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 6BA2C4007E; Tue, 24 May 2022 11:33:35 -0300 (-03) Date: Tue, 24 May 2022 11:33:35 -0300 From: Arnaldo Carvalho de Melo To: Jiri Olsa Cc: Thomas Richter , "linux-perf-use." , 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: X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Em Tue, May 24, 2022 at 02:10:17PM +0200, Jiri Olsa escreveu: > 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 I'm adding comments, testing and applying that series in my local tree, so far so good, will push to tmp.perf/core later. Please let us know if you guys looked at the patches in Jiri's perf/weak branch and if you are ok with it so that I can add Tested-by/acked-by/reviewed-by, which are always more than welcome. Thanks, - Arnaldo