Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753456AbaJUX4W (ORCPT ); Tue, 21 Oct 2014 19:56:22 -0400 Received: from LGEMRELSE7Q.lge.com ([156.147.1.151]:49614 "EHLO lgemrelse7q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751505AbaJUX4N (ORCPT ); Tue, 21 Oct 2014 19:56:13 -0400 X-Original-SENDERIP: 10.186.123.76 X-Original-MAILFROM: gioh.kim@lge.com Message-ID: <5446F28C.2070305@lge.com> Date: Wed, 22 Oct 2014 08:55:56 +0900 From: Gioh Kim User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 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?J8DMsMfIoyc=?= Subject: Re: [PATCH] mm: cma: split cma-reserved in dmesg log References: <1413790391-31686-1-git-send-email-pintu.k@samsung.com> <5445AD12.9080502@lge.com> <00cd01cfed32$1ebfd5b0$5c3f8110$@samsung.com> In-Reply-To: <00cd01cfed32$1ebfd5b0$5c3f8110$@samsung.com> Content-Type: text/plain; charset=EUC-KR Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2014-10-21 ???? 10:21, PINTU KUMAR ?? ??: > > Hi, > > ----- Original Message ----- >> From: Gioh Kim >> 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; ?̰?ȣ >> Sent: Tuesday, 21 October 2014 6:17 AM >> Subject: Re: [PATCH] mm: cma: split cma-reserved in dmesg log >> >> >> >> 2014-10-20 ???? 4:33, Pintu Kumar ?? ??: >>> 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 > > Ok, as per Andrew Morton comment, will remove CONFIG_CMA, > But then I need to put it under: include/linux/mm.h > In that case, it will solve the problem for CMA and non-CMA case. > Because, mm.h is already included in cma.c > >>> 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. >> > > Firstly, I want to move this to mm/page_alloc.c, so that it can be visible > for non-CMA cases. > Next, the purpose this variable is not only during init time. > Just like totalram_pages, I wanted to retain this variable to use it to > populate the CMA info, during /proc/meminfo. > Like: > CMATotal: (using totalcma_pages) > CMAFree: (using NR_FREE_CMA_PAGES) > I will post these changes in the next patch series. > Please let me know your comments. > >>> >>> 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. >> > > Ok agree. If we move totalcma_pages declaration to page_alloc.c and mm.h, > then we can get rid of CONFIG_CMA, to make it neat. > > >> I'm not sure but I think there is a debugfs file for cma. >> Can you use it? >> > > As of now, I think there is no debugfs for cma. > However, we can make one if required. > >> 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 >> > > I think this is not required. > For multiple CMA regions, this can be found under: > /sys/kernel/debug/memblock/reserved I'm sorry. I didn't know it. > However, as I said, we can populate this information under: /proc/meminfo > I think capturing it at one place will be better. For non-CMA cases, it > will be hidden. > Thus summary of CMA info can be seen in meminfo, and detailed information > can be seen in memblock/reserved. I agree with you. I'm looking forward to your next patch. > Do, let me know if you have any other idea? > >> >> -- >> 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 >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/