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 42A292DF153; Thu, 8 Jan 2026 11:11:36 +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=1767870697; cv=none; b=fExB6ySCk4QzGAFGcKlwvl9ijp3uLO94DhgdcFSAzSP8dMZfWLsKX0bcc+ivLsRExrmErRdD8MOXlBG9ERbqlnlqAIEgTJMYGwQMKX8tjo3HUbxIiXUv6PNkAi78X5VXCVuH4BJHLh1ZuwWFDDYox8pDrCAS6LGzLV9QRMeP/PI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767870697; c=relaxed/simple; bh=8CGN48JNNgwKs+LFLKHS2Kg9Tyylj9zBMrAZ2Ix4NqM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CawS+jJllwqjF2fZ1FJtitI6tCGacHW9PJh0NG5wFXfqbGmgFRw9S4zcuDbmHB0x5fjAU5tSJuiCW6jilr8qlM5//H6oDrGpmvxONrF5Hz4rAzR96Y/m5N9e23o0MpLczSQ2Y3c6IERrOx1plqCsJgHv8rC6j+dV8mKvHhThIow= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vZNvIQ77; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="vZNvIQ77" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 504BAC116C6; Thu, 8 Jan 2026 11:11:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767870696; bh=8CGN48JNNgwKs+LFLKHS2Kg9Tyylj9zBMrAZ2Ix4NqM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vZNvIQ77mok7jNAwIkIYd8+X0QzJ7gnG94/r/jd+BvcjzkwUA5kzRpUwhcaUNYJ+V z21s4u8JmKM8/UUcN8VI9P5qo7ydIgBCHlMjLti+kle92Oc4JaccFiW2PgSiP/ms6c atjUINLa/TW39k3436xld2zKjHngf3oRD6aM29r0= Date: Thu, 8 Jan 2026 12:11:32 +0100 From: Greg KH To: Leon Hwang Cc: stable@vger.kernel.org, Andrii Nakryiko , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Thomas Gleixner , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6.6.y 0/4] perf/x86/amd: add LBR capture support outside of hardware events Message-ID: <2026010809-matchless-reporter-3129@gregkh> References: <20260102090320.32843-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: stable@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: <20260102090320.32843-1-leon.hwang@linux.dev> On Fri, Jan 02, 2026 at 05:03:16PM +0800, Leon Hwang wrote: > Hi all, > > This backport wires up AMD perfmon v2 so BPF and other software clients > can snapshot LBR stacks on demand, similar to the Intel support > upstream. The series keeps the LBR-freeze path branchless, adds the > perf_snapshot_branch_stack callback for AMD, and drops the > sampling-only restriction now that snapshots can be taken from software > contexts. > > Leon Hwang (4): > perf/x86/amd: Ensure amd_pmu_core_disable_all() is always inlined > perf/x86/amd: Avoid taking branches before disabling LBR > perf/x86/amd: Support capturing LBR from software events > perf/x86/amd: Don't reject non-sampling events with configured LBR Why is this for a stable kernel? Isn't it a new feature? If you need this feature, why not use a newer kernel tree? thanks, greg k-h