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 B488B2FF490; Wed, 2 Jul 2025 17:14:31 +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=1751476471; cv=none; b=uVs2Qv38RXWMTZFhpudcOqMm33EeM4dy3uhogjyxzlWLpOuvrR0LO6P0y8b9QPrhvuHJuUBla4GHEYkciVLJNpMpjC1amNVOjFKOEwIdVmXTHeMsjfz5HMDAMykHu+lcfXnbl0T/UXEIxOHfJZi8CCI/iGg26nJxa83kQVAmgn8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751476471; c=relaxed/simple; bh=PrCZpvNyjYfUaaLn7PMgQspsagzM2AeP465bCGdyST8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JzkNVMQPmZ60TFbtwV+p+4Msyi2u6QwGgFEp242n5enDlczMKcdQXdxtRPVqFbjwLHuRD8B9MS9jNXXnHgrONem096s56uUeykdJ53K8k034cViRkFIl0Rh6eH4/L6TbpAxSB30cq2D9GldYO6yG3+mmTGhBn7c3YoTaohHFk7s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZFa93k7p; 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="ZFa93k7p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B466C4CEE7; Wed, 2 Jul 2025 17:14:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751476471; bh=PrCZpvNyjYfUaaLn7PMgQspsagzM2AeP465bCGdyST8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZFa93k7pHQsnWvDkyWsuQF6QgXzetPQCMJskiOaJ1VM+3PLN4VXJQ4bG88BXOLydy LtIjmllWrZrKlGpufY6hjlCSqekM8AR93RfG5wsuOU9SovGYci4NfHnM/MSajgnfn2 lVh4HU6KgiamaKrBIxtYbzC9ft22tyQsh1SWMlbfSG69FM4W2DfBpGR47gQdiBFxpv 5XNj7ghmU4PyomU5oL0Lak5EMRXnj5LpnVdrt8s1NCeQ1bz8zA0npppO6PbXmT2x11 Am8HBiWxOL25C2lDSHEZXulMrCCemm0wrksiAWoWlb8rTUdyFfVvdrh9nwhsqiIAbL VWvua0nZaStPg== Date: Wed, 2 Jul 2025 10:14:29 -0700 From: Namhyung Kim To: Steven Rostedt Cc: Sam James , fweimer@redhat.com, akpm@linux-foundation.org, andrii@kernel.org, axboe@kernel.dk, beaub@linux.microsoft.com, bpf@vger.kernel.org, indu.bhagat@oracle.com, jemarch@gnu.org, jolsa@kernel.org, jpoimboe@kernel.org, jremus@linux.ibm.com, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, mhiramat@kernel.org, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, x86@kernel.org Subject: Re: [PATCH v11 00/14] unwind_user: x86: Deferred unwinding infrastructure Message-ID: References: <878ql9mlzn.fsf@oldenburg.str.redhat.com> <87wm8qlsuk.fsf@gentoo.org> <20250702121502.6e9d6102@batman.local.home> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250702121502.6e9d6102@batman.local.home> On Wed, Jul 02, 2025 at 12:15:02PM -0400, Steven Rostedt wrote: > On Wed, 02 Jul 2025 12:44:51 +0100 > Sam James wrote: > > > In one of the commit messages in the perf series, Steven also gave > > `perf record -g -vv true` which was convenient for making sure it's > > correctly discovered deferred unwinding support. > > Although I posted the patch, the command "perf record -g -vv true" was > Namhyung's idea. Just wanted to give credit where credit was due. Yep, it's to check if perf tool ask the deferred callchain to the kernel. To check if the kernel returns the callchain properly is: $ perf report -D | grep -A5 CALLCHAIN_DEFERRED Thanks, Namhyung