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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5255DEB5947 for ; Wed, 11 Feb 2026 00:17:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 77C106B0005; Tue, 10 Feb 2026 19:17:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 729DF6B0089; Tue, 10 Feb 2026 19:17:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6359F6B008A; Tue, 10 Feb 2026 19:17:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 4E64A6B0005 for ; Tue, 10 Feb 2026 19:17:52 -0500 (EST) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id DA2DA1A0191 for ; Wed, 11 Feb 2026 00:17:51 +0000 (UTC) X-FDA: 84430262742.29.7BC7E5E Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf28.hostedemail.com (Postfix) with ESMTP id 244A3C0007 for ; Wed, 11 Feb 2026 00:17:49 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=d3fBm5Gv; spf=pass (imf28.hostedemail.com: domain of namhyung@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=namhyung@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1770769070; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=WwSDm0jLIQl/Dzlvma40bCMmh0XbO9qBdOum/94FVCU=; b=39V0Twjud6cPpu7d19I/s1T+vJCTAfrIE88GWFpiLbUs7H0etvBmDE6tgp/LyV38z5zISR 9cT6e4E6kghDCPezoUBM4ToFxlrnuMDMIzGxuFgZMEpQboPwdoqtT4PBQmnalRFo951wQV vclLCUIV40932sREkkASc+D3y0YbQ80= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=d3fBm5Gv; spf=pass (imf28.hostedemail.com: domain of namhyung@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=namhyung@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770769070; a=rsa-sha256; cv=none; b=jqPURKw18cjlVBReXGRzOI1GZscNVMdeFxCbXSYUdGm+2qxlwzVUiHdshrXZ69GswNMALP RkUf63aAs4jQMhV+7a59VPbwkKinwKBPjmJZREc5BW2jVOiUL4q8PLbUsCbvmpUW5h6VVN imlA5K3rLu0hpn/eK0lJ6Dvkl5dgzeE= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 1E86142DA1; Wed, 11 Feb 2026 00:17:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D7E0C116C6; Wed, 11 Feb 2026 00:17:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770769069; bh=X/PX6FbL34s4xBDSZ/RSuiPyyQFzkoB8wVlhJlcXfNE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=d3fBm5GvY71c46Z3yyUGu+knRQsYtlO5acDvD8eb13R8BszofgVIMcbhTiBqShC9j MGZNauvOVF56+3fYEW97TuWq+7OD0vYBzw8f1POL47D7+I2V0YVc5x1d2Vc8UdDxIq tHatD8oxuZOMW5QfnIogRP4pCr7LrJjCX8mimi5Ji3h5y4t5IiEvaAhE+0A7AWl4zq gPPWSULN9qiU0gGtb21aSxTUtSy+/2BYMPSB8AV+P2VH8qNy9DhFUw/v9B/2XBaPY9 cr9cVvNq/TqEtAOygG4DS0oTDFY6qUdQbfiMwzLkhTEGk3GXQMae5eh8Uy9n9TGtxB 3T+LQYaWYipBw== Date: Tue, 10 Feb 2026 16:17:46 -0800 From: Namhyung Kim To: Jens Remus Cc: Steven Rostedt , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org, Josh Poimboeuf , Masami Hiramatsu , Mathieu Desnoyers , Peter Zijlstra , Ingo Molnar , Jiri Olsa , Arnaldo Carvalho de Melo , Thomas Gleixner , Andrii Nakryiko , Indu Bhagat , "Jose E. Marchesi" , Beau Belgrave , Linus Torvalds , Andrew Morton , Florian Weimer , Kees Cook , Carlos O'Donell , Sam James , Dylan Hatch , Borislav Petkov , Dave Hansen , David Hildenbrand , "H. Peter Anvin" , "Liam R. Howlett" , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , Heiko Carstens , Vasily Gorbik Subject: Re: [PATCH v13 00/18] unwind_deferred: Implement sframe handling Message-ID: References: <20260127150554.2760964-1-jremus@linux.ibm.com> <20260205135411.5fb22df2@gandalf.local.home> <113e4e4d-8b7a-437d-a3a2-de74acc9ecaa@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <113e4e4d-8b7a-437d-a3a2-de74acc9ecaa@linux.ibm.com> X-Rspamd-Server: rspam11 X-Stat-Signature: ygspezbcqgpx3oy6cz5k1gaawkoisc6u X-Rspam-User: X-Rspamd-Queue-Id: 244A3C0007 X-HE-Tag: 1770769069-558410 X-HE-Meta: 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 edkivkiH d1V6MKH5JOY174IsYAabQBEHkwpTGkL/Z1hpLr82Rf+CQxFFiqKbTpz342Z+0k/3tne3Vw4Yil7vtUVI/JoOBpKKdTu8Ygagw1M1BoizQ6gNzZpxuJO7nVD/zzWIgz8Y6R4S4VzBrkKEEWOYeRINF7D+czK4arbDz7bTGvEJnnc4k7lazE5jO+77cgnP6gXAwyUWgyNAi0fz2MvKMso7JTLAjy/z5CPqFK3zftv3uYJalr3AfIsk5K9+EZWanFuyf4MpmEeIwzFl3F1LHNp4gnOVznUicD7Jp+rUzXp5EEkJwiWzopU3qdeLWsZKhOjeDdAGi X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hello, On Mon, Feb 09, 2026 at 06:07:59PM +0100, Jens Remus wrote: > On 2/5/2026 7:54 PM, Steven Rostedt wrote: > > On Thu, 5 Feb 2026 10:26:10 -0800 > > Namhyung Kim wrote: > > > >>> Namhyung Kim's related perf tools deferred callchain support can be used > >>> for testing ("perf record --call-graph fp,defer" and "perf report/script"). > >> > >> Is it possible for users to choose the unwinder - frame pointer or > >> SFrame at runtime? I feel like the option should be > >> "--call-graph sframe,defer" or just "--call-graph sframe" if it always > >> uses deferred unwinding. > > > > Currently no, and I'm not sure we want that do we? The idea is to use the > > best option that is available. Why use frame pointers if sframe is > > available and it's being called with defer? > > > > If there's no defer, then sframes are not available, so it defaults to the > > best option available (which will likely be frame pointers). Users (me, at least) may want to compare stacktraces from FP and SFrame? > > Maybe it would make sense not to "overload" the perf record option > "--call-graph fp,defer" and use it for all deferred unwinding methods. > > What about "--call-graph defer", "--call-graph any,defer", or > "--call-graph *,defer"? Sounds better. But I think it cannot enforce "--call-graph fp,defer" to use frame pointers when SFrame is available.. Hmm. Thanks, Namhyung