Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756694Ab3JNOmS (ORCPT ); Mon, 14 Oct 2013 10:42:18 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:50529 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755738Ab3JNOmR (ORCPT ); Mon, 14 Oct 2013 10:42:17 -0400 Message-ID: <525C02AE.8040507@ti.com> Date: Mon, 14 Oct 2013 10:41:50 -0400 From: Santosh Shilimkar User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Tejun Heo CC: , , , , , Andrew Morton 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2325 Lines: 64 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 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/