From nobody Sat Feb 7 18:52:11 2026 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 AF70929BDAD; Mon, 19 Jan 2026 23:04:08 +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=1768863848; cv=none; b=VGTbXVKOEB5O+qQcaEMIXsoANbaOXWeadGcDy+4wSeZ0o4swbSjGbxIWHqDJtT3mqQrRUs/23i4bQqeTkXocVQmU6fdAoLIYjKosTdAa6FXKZg3WEdORL6VM+1kX3ZOucnpddfdDcPeGr98xAmFYgE3dvFE5Oj/D6XyZSmbDUIU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768863848; c=relaxed/simple; bh=8BBEwEPOV2feM9asWnviMEeN61fjbzDKcbDTnI9BSWY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N5Qp+/TBS4VhfE4iyzwLWNwwrwUfz33ZHjNq/nhSLXUI9Nabz2H/YdFjf8jv+ViJHY7I6QRPlbB6flSqz07z3pmJFWUqCyP4kQ0HMy1cjd/QpUEIuI5XR+7XIinAni8UdG5WBMOGhTsLP7B7HUHSSvxmICPLma1kuq/zej+A+pA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ggts6Muq; 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="ggts6Muq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F420BC19423; Mon, 19 Jan 2026 23:04:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768863848; bh=8BBEwEPOV2feM9asWnviMEeN61fjbzDKcbDTnI9BSWY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ggts6MuqPRmp6JPKI/imH0YjdupgG5Kahp6IN70J2t4YhljglpCtvsW2PUxClQiDt Wj6Hp7ccAdgQvsCFQZvMpmP7bB96YInjP5Q/zNtIg9AqiTpTECEQpc9kKMrGX4pN0t g3dDc1LkJMKSq4460pcW4IT+gsEI4J+CDyG2zu6z2gQPaSl6aVVYh302a8Gs1s7yrw nvBRzFeoUppU9xGXtblIuqvYXVTFyJq2E16Y+kqYPerTaWPq+GM6IU11YHnz8WpJbA Q1HICF/dmj34sRYrmkAOizVVXHXgufQSJQBq7HwJwOBBpkZ0vSBys3vymkNvqTa/0+ pMNsBWcnlnQXw== From: "David Hildenbrand (Red Hat)" To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Broadcom internal kernel review list , linux-doc@vger.kernel.org, virtualization@lists.linux.dev, "David Hildenbrand (Red Hat)" , Andrew Morton , Oscar Salvador , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Arnd Bergmann , Greg Kroah-Hartman , Jerrin Shaji George , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Zi Yan Subject: [PATCH v3 21/24] mm/kconfig: make BALLOON_COMPACTION depend on MIGRATION Date: Tue, 20 Jan 2026 00:01:29 +0100 Message-ID: <20260119230133.3551867-22-david@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260119230133.3551867-1-david@kernel.org> References: <20260119230133.3551867-1-david@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Migration support for balloon memory depends on MIGRATION not COMPACTION. Compaction is simply another user of page migration. The last dependency on compaction.c was effectively removed with commit 3d388584d599 ("mm: convert "movable" flag in page->mapping to a page flag"). Ever since, everything for handling movable_ops page migration resides in core migration code. So let's change the dependency and adjust the description + help text. We'll rename BALLOON_COMPACTION separately next. Reviewed-by: Lorenzo Stoakes Acked-by: Michael S. Tsirkin Signed-off-by: David Hildenbrand (Red Hat) --- mm/Kconfig | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/mm/Kconfig b/mm/Kconfig index 24a3ff149a1b0..0d13c1b36e1c1 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -599,17 +599,14 @@ config MEMORY_BALLOON # # support for memory balloon compaction config BALLOON_COMPACTION - bool "Allow for balloon memory compaction/migration" + bool "Allow for balloon memory migration" default y - depends on COMPACTION && MEMORY_BALLOON - help - Memory fragmentation introduced by ballooning might reduce - significantly the number of 2MB contiguous memory blocks that can be - used within a guest, thus imposing performance penalties associated - with the reduced number of transparent huge pages that could be used - by the guest workload. Allowing the compaction & migration for memory - pages enlisted as being part of memory balloon devices avoids the - scenario aforementioned and helps improving memory defragmentation. + depends on MIGRATION && MEMORY_BALLOON + help + Allow for migration of pages inflated in a memory balloon such that + they can be allocated from memory areas only available for movable + allocations (e.g., ZONE_MOVABLE, CMA) and such that they can be + migrated for memory defragmentation purposes by memory compaction. =20 # # support for memory compaction --=20 2.52.0