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 EA64E6B0036 for ; Mon, 14 Oct 2013 10:41:55 -0400 (EDT) Received: by mail-pd0-f170.google.com with SMTP id x10so7506973pdj.1 for ; Mon, 14 Oct 2013 07:41:55 -0700 (PDT) Message-ID: <525C02AE.8040507@ti.com> Date: Mon, 14 Oct 2013 10:41:50 -0400 From: Santosh Shilimkar MIME-Version: 1.0 Subject: Re: [RFC 08/23] mm/memblock: debug: don't free reserved array if !ARCH_DISCARD_MEMBLOCK References: <1381615146-20342-1-git-send-email-santosh.shilimkar@ti.com> <1381615146-20342-9-git-send-email-santosh.shilimkar@ti.com> <20131013195111.GB18075@htj.dyndns.org> In-Reply-To: <20131013195111.GB18075@htj.dyndns.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: yinghai@kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, grygorii.strashko@ti.com, Andrew Morton On Sunday 13 October 2013 03:51 PM, Tejun Heo wrote: > On Sat, Oct 12, 2013 at 05:58:51PM -0400, Santosh Shilimkar wrote: >> 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 | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/mm/memblock.c b/mm/memblock.c >> index d903138..1bb2cc0 100644 >> --- a/mm/memblock.c >> +++ b/mm/memblock.c >> @@ -169,6 +169,10 @@ phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info( >> if (memblock.reserved.regions == memblock_reserved_init_regions) >> return 0; >> > > Please add comment explaining why the following test exists. It's > pretty difficult to deduce the reason only from the code. > ok. >> + if (IS_ENABLED(CONFIG_DEBUG_FS) && >> + !IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK)) >> + return 0; >> + > > Also, as this is another fix patch, can you please move this to the > head of the series? > Sure -- 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