From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5B133426EA3; Wed, 4 Feb 2026 15:20:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770218438; cv=none; b=lBdnpEXaOt/kHxsMTMDAHRPqzeQo+wKCByQVP4UaK6uYMYmF4ABJgCXJ7MMeUSxk/CsgfvhOAGc2ZhToTkEYDWHxbdFj0cnu7iBJicdkzBx41w81rDlw38rQXZ5sV9pQ4iwXmwPi161nVnHAgB2+N6i+OATtfxv32+b9ghWYH9Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770218438; c=relaxed/simple; bh=++9lYWzTdMOjgGXRPi1wm/r2DF+ABICab3CW23ZaRaU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nNk6u1XN+p4GvsGK9wHxDdd1YeTnoVPlsRMqtAkvzJ6yt5h5C9TkMHeb8lCKA0bQmRJ07w2eUChEKnJ9KYZuRImKKdiFYg8pydaUVcI/PGa1H872PXcJRBoPTOU2pXhQi186ih+deGxQVjDf46pv4n0jXrHvo79li5mG9QykAng= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PUXGSiyX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PUXGSiyX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60A23C116C6; Wed, 4 Feb 2026 15:20:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770218438; bh=++9lYWzTdMOjgGXRPi1wm/r2DF+ABICab3CW23ZaRaU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PUXGSiyX0isPBVHbRTYr/12v4GH9HH7Cqyv3xq1MajCbb/ofN2RFqCHIBuRNEWCX/ iT16LebdEOcYe+hSyVuv8eK72lPrJUwDbs67AoDd0W76PoHBlX2SG984hhlW2DQuI2 uAKqeNoNPqX6Y0unJevlyywBezRmKTpg86qDIiwrdx4cBnUhgmA7GXLSN2zNt+6rl1 cx4bDYiaSWkxYhFBa41IRgWM1+CI070nuJcGadMIFwM7GQpmeWtydHTAyHzb7rGIKd 78oZJpEFUtTe84/lSoaoxrLDQroTqS+DwGKpuhMOa1hdWNJb72t4svbPoyIbeh/rBC GsUj+a4Zh9nxA== Date: Wed, 4 Feb 2026 08:20:34 -0700 From: Tycho Andersen To: Namhyung Kim , Arnaldo Carvalho de Melo Cc: Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Chun-Tse Shao , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Ravi Bangoria , K Prateek Nayak Subject: Re: [PATCH] perf: fix segfault in `lock contention -b` Message-ID: References: <20260109164417.396138-1-tycho@kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Jan 13, 2026 at 01:18:52PM -0800, Namhyung Kim wrote: > On Mon, Jan 12, 2026 at 09:15:53AM -0700, Tycho Andersen wrote: > > On Fri, Jan 09, 2026 at 04:49:01PM -0800, Namhyung Kim wrote: > > > That said, can you add a NULL check in the init_numa_data() instead > > > and see how far it can go? > > > > Looks like not much further, it fails in lock_contention_bpf__load(): > > > > ./perf lock contention -b > > libbpf: kernel BTF is missing at '/sys/kernel/btf/vmlinux', was CONFIG_DEBUG_INFO_BTF enabled? > > libbpf: failed to find valid kernel BTF > > libbpf: kernel BTF is missing at '/sys/kernel/btf/vmlinux', was CONFIG_DEBUG_INFO_BTF enabled? > > libbpf: failed to find valid kernel BTF > > libbpf: Error loading vmlinux BTF: -ESRCH > > libbpf: failed to load BPF skeleton 'lock_contention_bpf': -ESRCH > > Failed to load lock-contention BPF skeleton > > lock contention BPF setup failed > > Thanks for checking this. I think it's ok to fail like this when BTF is > not enabled. Let me see if I can make some changes to run without it > later. Gentle ping, I was just reminded of this crash again this morning. Tycho