From nobody Sat Feb 7 05:57:15 2026 Received: from out-170.mta1.migadu.com (out-170.mta1.migadu.com [95.215.58.170]) (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 7D252341060 for ; Wed, 17 Dec 2025 09:47:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.170 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765964848; cv=none; b=jZ5OMsyVSpM47vn+Gof7msF3FG2vopgltwXFeYeaW0u+nMG/VY3sQMoetFthSWXlt1VJbzZoZM5ksiHunnEHsOliWaP9s1GMKoLhhF3ZDhZrHGiSWjcCZh9RjX3pqmkSObSZL3qQoYIMF1MG6GlzwtbT+au6Nj3f7b2osl4Su/w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765964848; c=relaxed/simple; bh=RY9iG5O6CRC3b3IlwlQVEJmAqDrdvdhuqhPIwDBxGks=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=auWxLYKg0VQbNXx4dJrOgmAChxKs68g6J1bbbTiaKPdVlWi3cCOZ6Irn8eV6HSgZTeimRLYypfNEdqcwIADD4LRHUT3pEBrPOq82nx+ZpdALmkLaKEEVF3/keSvw4ZE2sTPZd8MKZPv61kzGRDglpL3YqJ9N/mc2KD2jTtFioDI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=eZbKdt80; arc=none smtp.client-ip=95.215.58.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="eZbKdt80" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1765964844; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=e0pQYHM1jhSwp9PHWAhzAtLgw7dAo1EQ0j0b9Rhu8lM=; b=eZbKdt801jfBgSFgEebLAPk6aFKbypVWe1UElNxogEJ4s/53bKjwORbNSrNlyWSCOkda+i Lhm9zqaDBr7ecgDa//lbBuDtDX4Ri+RmkhjUGsFN7HRzueDoGBbjIgvq+DZgy/CSBkw0hv tJ2jZMUMODUAxuvOlRoR0+NH+XExscs= From: Qi Zheng To: will@kernel.org, aneesh.kumar@kernel.org, npiggin@gmail.com, peterz@infradead.org, dev.jain@arm.com, akpm@linux-foundation.org, david@kernel.org, ioworker0@gmail.com, linmag7@gmail.com Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-um@lists.infradead.org, Qi Zheng , Richard Weinberger , Anton Ivanov , Johannes Berg Subject: [PATCH v3 6/7] um: mm: enable MMU_GATHER_RCU_TABLE_FREE Date: Wed, 17 Dec 2025 17:45:47 +0800 Message-ID: In-Reply-To: References: 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 X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Qi Zheng On a 64-bit system, madvise(MADV_DONTNEED) may cause a large number of empty PTE page table pages (such as 100GB+). To resolve this problem, first enable MMU_GATHER_RCU_TABLE_FREE to prepare for enabling the PT_RECLAIM feature, which resolves this problem. Signed-off-by: Qi Zheng Cc: Richard Weinberger Cc: Anton Ivanov Cc: Johannes Berg --- arch/um/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/um/Kconfig b/arch/um/Kconfig index 8415d39b0d430..098cda44db225 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -42,6 +42,7 @@ config UML select HAVE_SYSCALL_TRACEPOINTS select THREAD_INFO_IN_TASK select SPARSE_IRQ + select MMU_GATHER_RCU_TABLE_FREE =20 config MMU bool --=20 2.20.1