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 211841E5B88; Mon, 2 Mar 2026 14:57:58 +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=1772463479; cv=none; b=CZn5WyJpbqahgTHc4zNvKHCx04vuafmIxxxDhxRgtXug4koXTOvrP4ZqAaN9wZq8tnZwOIVPco+dYYY1t4jpNX3Z+07RaVunZQh0UVXOaTufJt/zQF2Wj9JloXlgaK39soL04PfHxiFEjhilh9Wf54B8N1s7xzyyfFbjdMQDNhs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772463479; c=relaxed/simple; bh=fMcLgGLiLWawIvWbTImn1HNe87tRaYVtXMVhESlM6Yc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=vF2jid2cf1jn7cAjB/0wyEkgwb47veEN67WXR6Y1JKYQj1xtHWi4ANQGXs83vBEbqQ8x8Trrk/o4hYORjlfzVA9jXxjiT/4vf3MC9GBUQR/UBSX1V0//esbr6j2DuTdbYUGZqJRcMv1o72DBabBOslI8ZRKxDZx6AvNWKG+przs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p7WNU1np; 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="p7WNU1np" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C3E7C19423; Mon, 2 Mar 2026 14:57:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772463478; bh=fMcLgGLiLWawIvWbTImn1HNe87tRaYVtXMVhESlM6Yc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=p7WNU1npmxOzphIuGNHxdBRRvj8/rjl3c9gx0K4g6Iw4nSkQutJBId2bzAE2HiSbw A0/uzxzoOUQZu8UM79Fz35b80D+f92ZIZcbq8dzhBnVVsmm9U2I4UHBb1ixV86Ejcc I9QBbUgdFO0qH6u32wvjQhJZaXhXqTdJsNz64h+oMl2m0cboX26uqYHkmMTifb9k9i zid01OlV3McsGj7ijbn9o+md3rEF4hd0Tu+hM0dAr69r34AL8gL1PfzBCSudN4O2UP uGQQu1REIGu2zGPoOMErUU9+xf3KyLGODFEy7fKqW9Au+GIiKI/352Ogx/M2OKcDEx XPqShrSPGX9lQ== Message-ID: <2f14572e-e02b-4bc5-abd2-7814c24f7905@kernel.org> Date: Mon, 2 Mar 2026 15:57:50 +0100 Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/4] mm/page_reporting: add PAGE_REPORTING_ORDER_UNSPECIFIED To: Yuvraj Sakshith , akpm@linux-foundation.org, mst@redhat.com, jasowang@redhat.com, kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com Cc: linux-mm@kvack.org, virtualization@lists.linux.dev, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, xuanzhuo@linux.alibaba.com, eperezma@redhat.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com References: <20260302111757.2191056-1-yuvraj.sakshith@oss.qualcomm.com> <20260302111757.2191056-2-yuvraj.sakshith@oss.qualcomm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/2/26 12:17, Yuvraj Sakshith wrote: > Drivers can pass order of pages to be reported while > registering itself. Today, this is a magic number, 0. > > Label this with PAGE_REPORTING_ORDER_UNSPECIFIED and > check for it when the driver is being registered. > > This macro will be used in relevant drivers next. > > Signed-off-by: Yuvraj Sakshith > --- > include/linux/page_reporting.h | 1 + > mm/page_reporting.c | 14 +++++--------- > 2 files changed, 6 insertions(+), 9 deletions(-) > > diff --git a/include/linux/page_reporting.h b/include/linux/page_reporting.h > index fe648dfa3..d1886c657 100644 > --- a/include/linux/page_reporting.h > +++ b/include/linux/page_reporting.h > @@ -7,6 +7,7 @@ > > /* This value should always be a power of 2, see page_reporting_cycle() */ > #define PAGE_REPORTING_CAPACITY 32 > +#define PAGE_REPORTING_ORDER_UNSPECIFIED 0 > > struct page_reporting_dev_info { > /* function that alters pages to make them "reported" */ > diff --git a/mm/page_reporting.c b/mm/page_reporting.c > index e4c428e61..51cd88faf 100644 > --- a/mm/page_reporting.c > +++ b/mm/page_reporting.c > @@ -12,7 +12,7 @@ > #include "internal.h" > > /* Initialize to an unsupported value */ > -unsigned int page_reporting_order = -1; > +unsigned int page_reporting_order = PAGE_REPORTING_ORDER_UNSPECIFIED; > > static int page_order_update_notify(const char *val, const struct kernel_param *kp) > { > @@ -25,12 +25,7 @@ static int page_order_update_notify(const char *val, const struct kernel_param * > > static const struct kernel_param_ops page_reporting_param_ops = { > .set = &page_order_update_notify, > - /* > - * For the get op, use param_get_int instead of param_get_uint. > - * This is to make sure that when unset the initialized value of > - * -1 is shown correctly > - */ > - .get = ¶m_get_int, > + .get = ¶m_get_uint, > }; > > module_param_cb(page_reporting_order, &page_reporting_param_ops, > @@ -369,8 +364,9 @@ int page_reporting_register(struct page_reporting_dev_info *prdev) > * pageblock_order. > */ > > - if (page_reporting_order == -1) { > - if (prdev->order > 0 && prdev->order <= MAX_PAGE_ORDER) > + if (page_reporting_order == PAGE_REPORTING_ORDER_UNSPECIFIED) { > + if (prdev->order != PAGE_REPORTING_ORDER_UNSPECIFIED && > + prdev->order <= MAX_PAGE_ORDER) > page_reporting_order = prdev->order; > else > page_reporting_order = pageblock_order; I think the change to page_reporting_order (and param_get_int) should come after patch #4. Otherwise, you temporarily change the semantics of page_reporting_param_ops() etc. So you should perform the page_reporting_order changes either in patch #4 or in a new patch #5. Apart from that LGTM. -- Cheers, David