From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f52.google.com (mail-pa0-f52.google.com [209.85.220.52]) by kanga.kvack.org (Postfix) with ESMTP id E31896B0069 for ; Mon, 20 Oct 2014 20:50:18 -0400 (EDT) Received: by mail-pa0-f52.google.com with SMTP id fb1so177590pad.39 for ; Mon, 20 Oct 2014 17:50:18 -0700 (PDT) Received: from lgeamrelo01.lge.com (lgeamrelo01.lge.com. [156.147.1.125]) by mx.google.com with ESMTP id xd1si9227171pab.234.2014.10.20.17.50.16 for ; Mon, 20 Oct 2014 17:50:17 -0700 (PDT) Message-ID: <5445AD12.9080502@lge.com> Date: Tue, 21 Oct 2014 09:47:14 +0900 From: Gioh Kim MIME-Version: 1.0 Subject: Re: [PATCH] mm: cma: split cma-reserved in dmesg log References: <1413790391-31686-1-git-send-email-pintu.k@samsung.com> In-Reply-To: <1413790391-31686-1-git-send-email-pintu.k@samsung.com> Content-Type: text/plain; charset=EUC-KR Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Pintu Kumar , akpm@linux-foundation.org, 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, rientjes@google.com, vbabka@suse.cz, sasha.levin@oracle.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: cpgs@samsung.com, pintu_agarwal@yahoo.com, vishnu.ps@samsung.com, rohit.kr@samsung.com, ed.savinay@samsung.com, =?EUC-KR?B?wMywx8ij?= 2014-10-20 ?AEA 4:33, Pintu Kumar 3/4 ' +-U: > 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 > > Signed-off-by: Pintu Kumar > Signed-off-by: Vishnu Pratap Singh > --- > include/linux/swap.h | 3 +++ > mm/cma.c | 2 ++ > mm/page_alloc.c | 8 ++++++++ > 3 files changed, 13 insertions(+) > > diff --git a/include/linux/swap.h b/include/linux/swap.h > index 37a585b..beb84be 100644 > --- 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 > 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; I think __read_mostly is not good here. Cma areas often are rare but we cannot expect how many cma areas exists. > > 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 > I basically agree with your point. But CMA feature is not popular yet, so memory develoers probably doesn't like this. I'm not sure but I think there is a debugfs file for cma. Can you use it? Or what do you think about making another proc file to show cma area size and address? For instance, # cat /proc/cmainfo CMATotal: 400kB 0x10000000 300kB 0x20000000 100kB -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org