From patchwork Tue Oct 27 11:29:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 11860081 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B977AC55179 for ; Tue, 27 Oct 2020 11:36:17 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 46FBA22263 for ; Tue, 27 Oct 2020 11:36:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="TIaB5wrE"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="AC/jQYaY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 46FBA22263 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=TR74g5IxU1t7wUwsJk3PP5mwG8CgRtf2m9UVOU4n/XQ=; b=TIaB5wrEpUkp8dGf5rx7f2hNt HpPjFDjmfVnhXvWdAlZhKSlAPFUPCW+gT7Fjqi8htywFnfcSzNrd/FiuTvz1KKHdic/156a9M+szh NNCLIcmjP99izCuXznqBWynjkfkE/27mXMAE92rIZ1MDVCsseVYWCsbgrh256c9A00zc42ZqFrMAZ icyaC7w1b/bs5Mz/D8a6I2+73gMyY9B2AG7rqbuG2PXbRixxIzz+JtyA+yqAJBo5mU3Nka2SxH/ss QFQGtb87m6rI5IG9YPx/nIUsJj8Vb/RD13SNwE6XyrFbB5giDjw3j/uUGNqwlc6dgFTL+8Gdnahn7 T1U9s0WWA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kXNG6-0004qq-Tn; Tue, 27 Oct 2020 11:35:22 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kXNCS-000343-Li; Tue, 27 Oct 2020 11:31:40 +0000 Received: from aquarius.haifa.ibm.com (nesher1.haifa.il.ibm.com [195.110.40.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 78A2622283; Tue, 27 Oct 2020 11:31:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603798294; bh=Chq+OW8jPYeS0x1/w/NuhbNqJg7T410wGKW7Vwcmmh0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AC/jQYaY123wRTdPEyISNQSkrk6fK6qDgIgZMnbaYj/xrL1krmjOm1LUo+gXLR4O/ tvpoLxCRFDQgp+0/HxwTDihCaFuJJPQpjNci9DHja12IL0KC4fU5Ba+WHbgEJL1Jgn IrewywqVQYbPHxnQr4exw1rwLPXvUWiSB9GpQpzY= From: Mike Rapoport To: Andrew Morton Subject: [PATCH 13/13] m68k: deprecate DISCONTIGMEM Date: Tue, 27 Oct 2020 13:29:55 +0200 Message-Id: <20201027112955.14157-14-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201027112955.14157-1-rppt@kernel.org> References: <20201027112955.14157-1-rppt@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201027_073137_043698_BA6D6E28 X-CRM114-Status: GOOD ( 21.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, Catalin Marinas , linux-mm@kvack.org, Will Deacon , Greg Ungerer , Jonathan Corbet , Meelis Roos , Russell King , Mike Rapoport , Geert Uytterhoeven , Matt Turner , linux-snps-arc@lists.infradead.org, Alexey Dobriyan , linux-m68k@lists.linux-m68k.org, John Paul Adrian Glaubitz , linux-arm-kernel@lists.infradead.org, Michael Schmitz , Tony Luck , Vineet Gupta , linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, Mike Rapoport Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Mike Rapoport DISCONTIGMEM was intended to provide more efficient support for systems with holes in their physical address space that FLATMEM did. Yet, it's overhead in terms of the memory consumption seems to overweight the savings on the unused memory map. For a ARAnyM system with 16 MBytes of FastRAM configured, the memory usage reported after page allocator initialization is Memory: 23828K/30720K available (3206K kernel code, 535K rwdata, 936K rodata, 768K init, 193K bss, 6892K reserved, 0K cma-reserved) and with DISCONTIGMEM disabled and with relatively large hole in the memory map it is: Memory: 23864K/30720K available (3197K kernel code, 516K rwdata, 936K rodata, 764K init, 179K bss, 6856K reserved, 0K cma-reserved) Moreover, since m68k already has custom pfn_valid() it is possible to define HAVE_ARCH_PFN_VALID to enable freeing of unused memory map. The minimal size of a hole that can be freed should not be less than MAX_ORDER_NR_PAGES so to achieve more substantial memory savings let m68k also define custom FORCE_MAX_ZONEORDER. With FORCE_MAX_ZONEORDER set to 9 memory usage becomes: Memory: 23880K/30720K available (3197K kernel code, 516K rwdata, 936K rodata, 764K init, 179K bss, 6840K reserved, 0K cma-reserved) Signed-off-by: Mike Rapoport --- arch/m68k/Kconfig.cpu | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu index 3af0fca03803..763bc80a27aa 100644 --- a/arch/m68k/Kconfig.cpu +++ b/arch/m68k/Kconfig.cpu @@ -21,6 +21,7 @@ choice config M68KCLASSIC bool "Classic M68K CPU family support" select NEED_MULTIPLE_NODES if DISCONTIGMEM + select HAVE_ARCH_PFN_VALID if FLATMEM && !SINGLE_MEMORY_CHUNK config COLDFIRE bool "Coldfire CPU family support" @@ -378,11 +379,34 @@ config SINGLE_MEMORY_CHUNK help Ignore all but the first contiguous chunk of physical memory for VM purposes. This will save a few bytes kernel size and may speed up - some operations. Say N if not sure. + some operations. + When this option os set to N, you may want to lower "Maximum zone + order" to save memory that could be wasted for unused memory map. + Say N if not sure. config ARCH_DISCONTIGMEM_ENABLE + depends on BROKEN def_bool MMU && !SINGLE_MEMORY_CHUNK +config FORCE_MAX_ZONEORDER + int "Maximum zone order" if ADVANCED + depends on !SINGLE_MEMORY_CHUNK + default "11" + help + The kernel memory allocator divides physically contiguous memory + blocks into "zones", where each zone is a power of two number of + pages. This option selects the largest power of two that the kernel + keeps in the memory allocator. If you need to allocate very large + blocks of physically contiguous memory, then you may need to + increase this value. + + For systems that have holes in their physical address space this + value also defines the minimal size of the hole that allows + freeing unused memory map. + + This config option is actually maximum order plus one. For example, + a value of 11 means that the largest free memory block is 2^10 pages. + config 060_WRITETHROUGH bool "Use write-through caching for 68060 supervisor accesses" depends on ADVANCED && M68060