From nobody Tue Feb 10 03:00:09 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 27348194C96; Thu, 15 Jan 2026 09:22:41 +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=1768468962; cv=none; b=S6o2LDvhxxFrJDgCRArHVHqak71zIOescqVjFMulj1hw/tn/9mAEe5KgMk1TsTcroTYleTUhzLLOHmMr3HnXYLpALRlAuFtBBYCJBRky1xsyldUReMTCniFVfXV09wgecblBN83VaehYWiVZ8KVOZxof62w6LNUKiFA977+o56U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768468962; c=relaxed/simple; bh=nMSbJ130FsUcdSsvFUeUBR1YMlPlSjm9XeIRM/kAkzM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MNbqjVPVap29dGngtLr0ZqArl67Osai61UDdWPe5S7ExHOvG10M0Xxxecqh0bJY9EJEx/d9szuAAl7AXdNEVzxsPbtFbJ5baQFchFf/dCaufuWkYsF2u8UWHXceY6gZeydyXZ8EelZbWsVGuOLQIfsHv9aPXA4S+nj+2FUAhjWw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O8jYzSQQ; 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="O8jYzSQQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 948EDC116D0; Thu, 15 Jan 2026 09:22:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768468961; bh=nMSbJ130FsUcdSsvFUeUBR1YMlPlSjm9XeIRM/kAkzM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O8jYzSQQhivp9+oi3e+25bY5iCyiGPyPZY4Q5d6BT6vIFTT2h6LTECelzgIQUwBam xm93YDpR/+tfwHTtSoZFn4io0EPnm7MXDaUCFJBiGSmOzZEsonSTnTAxHsKjgTmePs H1WVZ6Ru1nLs8fYp2MEhnZtBPHrn7pIJQJ4NUvjSZQzddO+dTHGoMvFy05u0Yzgkpg 9S7YHWca/kqlFCmPhigeFIAT6icw+tMlOJZGExUL4+q8ikAyOvua74wdBt7xThNHPm pwqoKl6EwJ/Zyx8ks0VFdx3aSfDNXWYRAOTML42Re/Qkt3iA/jsQXyOkuLXfvG+dA4 H6XnATH7JX0Lg== 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 v2 20/23] mm/kconfig: make BALLOON_COMPACTION depend on MIGRATION Date: Thu, 15 Jan 2026 10:20:10 +0100 Message-ID: <20260115092015.3928975-21-david@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260115092015.3928975-1-david@kernel.org> References: <20260115092015.3928975-1-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. Signed-off-by: David Hildenbrand (Red Hat) Reviewed-by: Lorenzo Stoakes --- 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