From nobody Tue Feb 10 02:00:29 2026 Received: from out-180.mta1.migadu.com (out-180.mta1.migadu.com [95.215.58.180]) (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 72B2030DD24; Tue, 27 Jan 2026 12:16:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.180 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769516212; cv=none; b=a6eizgsFCNjKccoNADcAW+mQ/g7ieh3kr3SVtL8Rn6UtWjbOuhdhLTepwkpy7B96FATqAjG4Uo3TZvNDWMIg76eFkL8KuUzpCU0FVlmtRTC7wxcEIIc0Q8yDapUuHVg4uvR55VaGa3bQxxwbnCIDrCpOdFUz7xuaJcwesUD9gOw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769516212; c=relaxed/simple; bh=RY9iG5O6CRC3b3IlwlQVEJmAqDrdvdhuqhPIwDBxGks=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=guixxTow5IgLdWUq4jo0MmOCzA4Dhn4an2VX+sWglmTnXLUTYdei7Fe5RKfNhqdNETkM9aZZMflfeXdP6m47bBlXJY/n7yP9URkGNVwoBrorsbNIadNEhc/TcbKEji1zl90TnXSLj9E4VjMnQY7q0XXhmolg+Sd6Q9GwYaoUyjM= 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=wc/LzcSY; arc=none smtp.client-ip=95.215.58.180 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="wc/LzcSY" 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=1769516209; 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=wc/LzcSY84XUN/M01s5VcIBtD1/lXhQlVZzRwxMLJY1XGT2wxJOzGUzWA5oPCfbPCsb1/O ht9YXkU/ZBWYV/j9FZpfqWjqnjxWaip5QHGmFskLEMQc1kWqyHjiSkHOF+suDP3tIX1G7K JeMpI6zZYGFo3G12ozp0269DFGB3g9I= From: Qi Zheng To: david@kernel.org, andreas@gaisler.com, richard.weiyang@gmail.com, will@kernel.org, peterz@infradead.org, aneesh.kumar@kernel.org, npiggin@gmail.com, dev.jain@arm.com, ioworker0@gmail.com, linmag7@gmail.com, akpm@linux-foundation.org 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, sparclinux@vger.kernel.org, Qi Zheng , Richard Weinberger , Anton Ivanov , Johannes Berg Subject: [PATCH v4 6/8] um: mm: enable MMU_GATHER_RCU_TABLE_FREE Date: Tue, 27 Jan 2026 20:12:59 +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