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 34E262E62A0 for ; Sat, 5 Apr 2025 09:07:00 +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=1743844021; cv=none; b=UGjP9JuFZhLx4MfayUPWc7DNxlJMhqF8odLsysLVAE2zGY/yYzxJfufACgjLp3/3IVxm4PG0PNhnoWVnuFDDoz3llRLA6WaNNIN4d0rW8hj7WkHfWK1W1Q6mmwzeh3KMZItFu7KI0WfGNm+vJ8UVTZDob6do7juDRSwSIGLOX5c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743844021; c=relaxed/simple; bh=hmo4SkEfKVQ+JtittZixzT5qMxahWc1LMsBGP6j/eDI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=H+d8G8spJaBMXChMOZknQ2cA67Wm2wuF0pBRXqUQ6tHbhmL4MEL1YcsI1uWnpMCVUVZWdE2LyNYvT+w5YuRipZ8faiskErfaWTqKfeMUwVqfMBrgoouxtqPjjLXSBeikLxsyXnLkmHblHBfqbe0cXPNht0dBbuh9cjv9xDvfxz8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B1I+YMgL; 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="B1I+YMgL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60D81C4CEE4; Sat, 5 Apr 2025 09:06:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743844020; bh=hmo4SkEfKVQ+JtittZixzT5qMxahWc1LMsBGP6j/eDI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=B1I+YMgLbUZLoiXEBIQVW+nP7YLIl5gMopWOdGVmV2AA8PSdseBoLdc0QpoeyW/3B UvBue9CJE+COrwhTJtP5jMub9OyFVPIKs02p0iVrzgDMJyuX1xtz9Jtw1Nu0arzDrV nI/agJS6i4xMWjte7nbMq7sttPEQhYwuglAKdpuUzS0/VCUJV0cAZR1xNnCJ095jT4 tsx2aRoeVjJYRVcOLTJi/8SWzuFtZ6gor3YWqUKtcx7+PWaSy4Geh7wCPyn0eLeA1m bRYHi9gPIi59Hc0DlBwJ8/hsePL0+6E3kwpeq1cJteJPiT8e7MPfIUPMDpbb9ppsKF jcr123+aVYujA== Date: Sat, 5 Apr 2025 11:06:50 +0200 From: Ingo Molnar To: Namhyung Kim Cc: Arnaldo Carvalho de Melo , Ian Rogers , Kan Liang , Jiri Olsa , Adrian Hunter , Peter Zijlstra , linux-perf-users@vger.kernel.org, Dmitry Vyukov Subject: Re: [perf top] annotation doesn't work, libunwind doesn't seem to be working either Message-ID: References: <20250307080829.354947-1-namhyung@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: * Namhyung Kim wrote: > > /usr/bin/ld: test-libunwind.c:(.text+0x44): undefined reference to `_Ux86_64_init_remote' > > /usr/bin/ld: test-libunwind.c:(.text+0x6b): undefined reference to `_Ux86_64_dwarf_search_unwind_table' > > collect2: error: ld returned 1 exit status > > > > I tried to install the libunwind-19-dev package, I tried to > > uninstall/reinstall - no combination seems to work. > > > > perf is also totally unhelpful about resolving such issues - it used to > > issue tips about what packages to install, but those tips are not > > present anymore, for this one at least. > > Since v6.13, we switched to disable libunwind by default and used > unwinding in libdw. > > commit 13e17c9ff491 ("perf build: Make libunwind opt-in rather than > opt-out") > > You need to pass LIBUNWIND=1 to build with it. So, users (including me) have absolutely no idea which unwinding library they want to build with: 99% of them would like to have a clean, full-featured perf build with all libraries marked as '[ on ]' in the build log. :-) > > Within 'perf top' I go into a function, and I press 's', which is > > supposed to toggle the source code annotation ... but nothing happens. > > > > 'nothing happens' is perhaps the most passive-aggressive reaction a > > tool can give to a user. I'd prefer a *crash* to ignoring the keypress > > ... > > Oh ok. I prefer a warning. :) There's a zillion other things I'd prefer over the current behavior, what I wanted to say was that *even a crash* is superior to a puzzling 'nothing' :-) Thanks, Ingo