From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f182.google.com (mail-qt1-f182.google.com [209.85.160.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2C3A3330B2D for ; Tue, 16 Jun 2026 13:49:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781617773; cv=none; b=u+UP3AvudyBHx2KG1+Lc6U3hmCHXp2LVM0NG8i7MbPBacv7kFv9Ib43liu7bqwtYDxRGq8aooDnm9boJvDLLPyQoD8EqcHi8ALAcrB/urJo7caEwhkra5wvtsE2B4yUT6HnTF8a80t9+6K12p9V0hZK3WUzbOK16yXx6EMQtm9M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781617773; c=relaxed/simple; bh=qqXuoXoNvjp4qDCvrGTDj7/LLZWDQAWHA8I4Imc6j+Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GRpyXaeZ9DdbrWn6jCeYozbfFaRyjKhjL3Cc4DyYNLCEMMdvZiCEBs7iVgLkmcQP8dK6740aQfqbHHmXjCxmJXlg9UYxK0dgfk9/QwrpM64qEjrzYmKgPvVBJtBAiIdjHTwhvza4gb2oORbk0Oz/EVHY6I1rGwlhIE0McjP7+Wc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net; spf=pass smtp.mailfrom=gourry.net; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b=iedOfZgB; arc=none smtp.client-ip=209.85.160.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gourry.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b="iedOfZgB" Received: by mail-qt1-f182.google.com with SMTP id d75a77b69052e-517a5cafc3dso50168111cf.3 for ; Tue, 16 Jun 2026 06:49:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1781617771; x=1782222571; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=rsshTlVmdyNb6wSnpo8oIqSGy6qOuJMEcgLTNFP6fPI=; b=iedOfZgB8+6+aAZD/QzhPlHxWMtbjCDO2Exm/VNlPK16BrAqOcJkTRDM1CldWDT6Hw mXgH1LV+cX3zp1pP5LUZcFw9Pn2ymOKkHEDCupKO93AY26acWLnDSTmFNMYxpBqqXxrG WlmkBb4Tv3QZLXRTp4VRak5zQUohax870QZnv6A4OqZvJkfFGkJR7HhO5qoNWTPIrhm4 W6jc4RfvvN8Bjeg3acMl+GybhYNF75Euh2VFsqXxEWLmoWzHCbbYxodivyQAijqwAyW0 1yXtwqrKXCbAqptUAcnqJwIIhp8xdJDRnqrpNMnsIYxpBvJO3AUOpYIRjruvXJoGpQIZ ArKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781617771; x=1782222571; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=rsshTlVmdyNb6wSnpo8oIqSGy6qOuJMEcgLTNFP6fPI=; b=raTp75WIX6A50oMMo4XhxagbG4FD1a0GTt2FAwz+sg39gg1dyxYeKttJst62MZtUNN BM6JZs/nRm6X+/BUCsK/tkAYkA0+sicLAhl9zNaUhA81txNzv7D/GbwOQh7Sd2y9GhxP h3xeOvRyv/V8JcR02iPkP6qrNntkKJdAv8DXmzFaRxjuxK0UZ6E+E/9Thw51+3UbSqXc 7vOt8bmhbI/L8ms442W7R9GF4ZpZEyeBQq9S5fgtjOMtxWtBp/8xx0R30U/vguNwAU1O vZn7FL03ybPU8yoidvWQmBvrQ/d5Td6iKeSVaqeY6dLL1aCHg39B/4/JjQtwGtrsCrvx Rm0g== X-Forwarded-Encrypted: i=1; AFNElJ8SZ5g7TI2FzK1bjEP3u1zLaG64Uc+r2lDj2CEfJY2sbOGfAVSD/b79EFCMCWQM/0CijzrB0Nxv8prx0zk=@vger.kernel.org X-Gm-Message-State: AOJu0YxeWD8rjlY/fgJJzfQHIMfL3lmfDWx9fxzfH/QtlFkTl2WUuDoT TPehc6bMrJAoefCrYaxTwmxf6QJgNqG5aB+kHe6dxOD8zq3WWYqb4bAuC4ZDiNEZjAg= X-Gm-Gg: Acq92OGyMn3NJKvu7deYkQPGTpGlGQV3KbC2uz08BUPzvw9BiPBFmOEXlx7NKU5XPYY WaXKxB5a8yp8G5NVT0eHp7xq+pqye70nrdZ1zGtJnRs3gUUNx3EZIgcWad2I8z0nem3wlxSLhka qJX2au0A3DoSgu7GB9I3snc8SuBo/H4+pr+0fVs6H8SBo2qMCV8troH20zcZR//glvz35v/CKHD MRzgE/g1UfeveW9/O8+CA8wbqYk5lZ+w6b2gTfVoScqehj5AObmzJMB5+iT+h/w7Y53fbBMtLSX lubes8V8LERsi0YaYEqL39QWWZFk14Zl4bxD2ytf2dD9NK3vY/2CqNvW8G9RJC1/AKIbMjbgpML Eq9SG1XeIhDPD9gxvJGCCuGL+O8mCFZMjc8RAzsxYs/HvcO35G79+lRikvqTlhZ8iYApqrpNp3O 8GMEX8GgGEsLM+APZ/OvfjSgobnLfL7Bs= X-Received: by 2002:ac8:7d89:0:b0:517:5f7e:a30c with SMTP id d75a77b69052e-519916ae9d9mr49617441cf.4.1781617771128; Tue, 16 Jun 2026 06:49:31 -0700 (PDT) Received: from gourry-fedora-PF4VCD3F ([2620:10d:c091:500::3:437e]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-517fb7a00desm151217661cf.19.2026.06.16.06.49.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jun 2026 06:49:30 -0700 (PDT) Date: Tue, 16 Jun 2026 09:49:28 -0400 From: Gregory Price To: "David Hildenbrand (Arm)" Cc: virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, kernel-team@meta.com, mst@redhat.com, jasowang@redhat.com, xuanzhuo@linux.alibaba.com, eperezma@redhat.com, hannes@cmpxchg.org, surenb@google.com, peterz@infradead.org, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kprateek.nayak@amd.com Subject: Re: [RFC PATCH 1/2] virtio-balloon: extend stats with memory composition and pressure data Message-ID: References: <20260513165006.2790857-1-gourry@gourry.net> <20260513165006.2790857-2-gourry@gourry.net> <8e766803-e68d-4efd-a69e-cec5b2492988@kernel.org> 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=us-ascii Content-Disposition: inline In-Reply-To: <8e766803-e68d-4efd-a69e-cec5b2492988@kernel.org> On Tue, Jun 16, 2026 at 02:30:34PM +0200, David Hildenbrand (Arm) wrote: > > Nothing too crazy here, however, the question is which of these values we > actually want to guarantee that we will provide them with unchanged semantics in > the future ... I guess anything we already expose to user space is alright > (because it effectively already must remain mostly unchanged I assume). > I suppose a risk of them going away entirely? I suppose that's fixable but unlikely. ~Gregory