From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f170.google.com (mail-pd0-f170.google.com [209.85.192.170]) by kanga.kvack.org (Postfix) with ESMTP id 247086B008C for ; Fri, 8 Nov 2013 18:43:11 -0500 (EST) Received: by mail-pd0-f170.google.com with SMTP id v10so2808620pde.29 for ; Fri, 08 Nov 2013 15:43:10 -0800 (PST) Received: from psmtp.com ([74.125.245.185]) by mx.google.com with SMTP id hk1si8054839pbb.311.2013.11.08.15.43.08 for ; Fri, 08 Nov 2013 15:43:09 -0800 (PST) From: Santosh Shilimkar Subject: [PATCH 02/24] mm/memblock: debug: don't free reserved array if !ARCH_DISCARD_MEMBLOCK Date: Fri, 8 Nov 2013 18:41:38 -0500 Message-ID: <1383954120-24368-3-git-send-email-santosh.shilimkar@ti.com> In-Reply-To: <1383954120-24368-1-git-send-email-santosh.shilimkar@ti.com> References: <1383954120-24368-1-git-send-email-santosh.shilimkar@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: tj@kernel.org, linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, Grygorii Strashko , Yinghai Lu , Andrew Morton , Santosh Shilimkar From: Grygorii Strashko Now the Nobootmem allocator will always try to free memory allocated for reserved memory regions (free_low_memory_core_early()) without taking into to account current memblock debugging configuration (CONFIG_ARCH_DISCARD_MEMBLOCK and CONFIG_DEBUG_FS state). As result if: - CONFIG_DEBUG_FS defined - CONFIG_ARCH_DISCARD_MEMBLOCK not defined; - reserved memory regions array have been resized during boot then: - memory allocated for reserved memory regions array will be freed to buddy allocator; - debug_fs entry "sys/kernel/debug/memblock/reserved" will show garbage instead of state of memory reservations. like: 0: 0x98393bc0..0x9a393bbf 1: 0xff120000..0xff11ffff 2: 0x00000000..0xffffffff Hence, do not free memory allocated for reserved memory regions if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK). Cc: Yinghai Lu Cc: Tejun Heo Cc: Andrew Morton Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- mm/memblock.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mm/memblock.c b/mm/memblock.c index e03918e..88a6a0e 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -167,6 +167,19 @@ phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info( if (memblock.reserved.regions == memblock_reserved_init_regions) return 0; + /* + * Don't allow Nobootmem allocator to free reserved memory regions + * array if + * - CONFIG_DEBUG_FS is enabled; + * - CONFIG_ARCH_DISCARD_MEMBLOCK is not enabled; + * - reserved memory regions array have been resized during boot. + * Otherwise debug_fs entry "sys/kernel/debug/memblock/reserved" + * will show garbage instead of state of memory reservations. + */ + if (IS_ENABLED(CONFIG_DEBUG_FS) && + !IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK)) + return 0; + *addr = __pa(memblock.reserved.regions); return PAGE_ALIGN(sizeof(struct memblock_region) * -- 1.7.9.5 -- 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