From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754023AbaJTWsS (ORCPT ); Mon, 20 Oct 2014 18:48:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57609 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753961AbaJTWsR (ORCPT ); Mon, 20 Oct 2014 18:48:17 -0400 Date: Mon, 20 Oct 2014 15:48:16 -0700 From: Andrew Morton To: Pintu Kumar Cc: hannes@cmpxchg.org, riel@redhat.com, mgorman@suse.de, vdavydov@parallels.com, nasa4836@gmail.com, ddstreet@ieee.org, m.szyprowski@samsung.com, mina86@mina86.com, iamjoonsoo.kim@lge.com, aneesh.kumar@linux.vnet.ibm.com, lauraa@codeaurora.org, gioh.kim@lge.com, rientjes@google.com, vbabka@suse.cz, sasha.levin@oracle.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, cpgs@samsung.com, pintu_agarwal@yahoo.com, vishnu.ps@samsung.com, rohit.kr@samsung.com, ed.savinay@samsung.com Subject: Re: [PATCH] mm: cma: split cma-reserved in dmesg log Message-Id: <20141020154816.9403d8684639d968948b7134@linux-foundation.org> In-Reply-To: <1413790391-31686-1-git-send-email-pintu.k@samsung.com> References: <1413790391-31686-1-git-send-email-pintu.k@samsung.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 20 Oct 2014 13:03:10 +0530 Pintu Kumar wrote: > When the system boots up, in the dmesg logs we can see > the memory statistics along with total reserved as below. > Memory: 458840k/458840k available, 65448k reserved, 0K highmem > > When CMA is enabled, still the total reserved memory remains the same. > However, the CMA memory is not considered as reserved. > But, when we see /proc/meminfo, the CMA memory is part of free memory. > This creates confusion. > This patch corrects the problem by properly substracting the CMA reserved > memory from the total reserved memory in dmesg logs. > > Below is the dmesg snaphot from an arm based device with 512MB RAM and > 12MB single CMA region. > > Before this change: > Memory: 458840k/458840k available, 65448k reserved, 0K highmem > > After this change: > Memory: 458840k/458840k available, 53160k reserved, 12288k cma-reserved, 0K highmem > > ... > > --- a/include/linux/swap.h > +++ b/include/linux/swap.h > @@ -295,6 +295,9 @@ static inline void workingset_node_shadows_dec(struct radix_tree_node *node) > /* linux/mm/page_alloc.c */ > extern unsigned long totalram_pages; > extern unsigned long totalreserve_pages; > +#ifdef CONFIG_CMA > +extern unsigned long totalcma_pages; > +#endif We don't actually need the ifdefs here - the kernel will compile OK without them. This means that a programming error will result in a link-time error rather than a compile-time error but that's a pretty small cost to pay for keeping the header files neater. > extern unsigned long dirty_balance_reserve; > extern unsigned long nr_free_buffer_pages(void); > extern unsigned long nr_free_pagecache_pages(void); > diff --git a/mm/cma.c b/mm/cma.c > index 963bc4a..73fe7be 100644 > --- a/mm/cma.c > +++ b/mm/cma.c > @@ -45,6 +45,7 @@ struct cma { > static struct cma cma_areas[MAX_CMA_AREAS]; > static unsigned cma_area_count; > static DEFINE_MUTEX(cma_mutex); > +unsigned long totalcma_pages __read_mostly; This could+should be __initdata. > phys_addr_t cma_get_base(struct cma *cma) > { > @@ -288,6 +289,7 @@ int __init cma_declare_contiguous(phys_addr_t base, > if (ret) > goto err; > > + totalcma_pages += (size / PAGE_SIZE); > pr_info("Reserved %ld MiB at %08lx\n", (unsigned long)size / SZ_1M, > (unsigned long)base); > return 0; > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index dd73f9a..c6165ac 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5521,6 +5521,9 @@ void __init mem_init_print_info(const char *str) > pr_info("Memory: %luK/%luK available " > "(%luK kernel code, %luK rwdata, %luK rodata, " > "%luK init, %luK bss, %luK reserved" > +#ifdef CONFIG_CMA > + ", %luK cma-reserved" > +#endif > #ifdef CONFIG_HIGHMEM > ", %luK highmem" > #endif > @@ -5528,7 +5531,12 @@ void __init mem_init_print_info(const char *str) > nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10), > codesize >> 10, datasize >> 10, rosize >> 10, > (init_data_size + init_code_size) >> 10, bss_size >> 10, > +#ifdef CONFIG_CMA > + (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10), > + totalcma_pages << (PAGE_SHIFT-10), > +#else > (physpages - totalram_pages) << (PAGE_SHIFT-10), > +#endif > #ifdef CONFIG_HIGHMEM > totalhigh_pages << (PAGE_SHIFT-10), > #endif Do we really need any of the ifdefs? A non-CMA kernel will print "0K cma-reserved" but is that harmful? This is all __init code so the additional code bloat isn't a significant issue.