From nobody Mon Feb 9 16:34:47 2026 Received: from out-184.mta0.migadu.com (out-184.mta0.migadu.com [91.218.175.184]) (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 AF9173148C6; Fri, 14 Nov 2025 11:14:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.184 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763118850; cv=none; b=GEhGEwiKWqfc/9v9WuhqC5/NfXwyQ21rpwwbmlhOpsA7j3ZbMM9q2hNeTKsjF9FdXjs9zHRCGL+WZbrNo4GJ7EWnAl1biP5Zo9JULCD+vn3BJDZXa9pf8bGE8OisklHXTqOpyQtyFBke0LbqLF1xIMv0v7+j1j8Hmr8VLP33CRQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763118850; c=relaxed/simple; bh=L77VHJOsxYGfJl12t5E1P3bJEqsaMDW4GIC4V2YxBI4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OL1T1d4Vb3dXTI3rJQX1N/NQDV3mhc8X4pnunO1vJAHRJWvPb6NwfjkKbtm97P9+fMSzIra5ZU9RuYo2+Hjgi7OYgv1HMY+cmeDZ70kyCfN36maqxHi4j/cDEY2SX/jK/PQgSahhEWeDVvY6tD/1eILRBkmFfClnK/LFFlmlKrY= 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=L48H43W4; arc=none smtp.client-ip=91.218.175.184 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="L48H43W4" 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=1763118845; 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=nUnrWplutHBzvgR2dvaxPt91n3EUIlT8RN+kjzr9YeU=; b=L48H43W4jFZRnZVw9O79JRiRB5m9aw/GV0MPdZjIrgDSOzS1xJajXCccgoMGVVyjHQVMx8 ixGDGcGZ9+fwVuXGogoz7wJwNfE66muSzsaVj6jY+ONOTTSdEs5AZWkbAoLKzZN3TJkNEr SLREeZzO+x0CEbQrd41ME+/n9u8TpH4= 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@redhat.com, ioworker0@gmail.com Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.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 6/7] um: mm: enable MMU_GATHER_RCU_TABLE_FREE Date: Fri, 14 Nov 2025 19:11:20 +0800 Message-ID: <27f173b0fc6fdf92104721fc3daba8d7d9d31e2f.1763117269.git.zhengqi.arch@bytedance.com> 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 097c6a6265ef3..47a41bc77bb24 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -41,6 +41,7 @@ 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