From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f181.google.com (mail-pd0-f181.google.com [209.85.192.181]) by kanga.kvack.org (Postfix) with ESMTP id 07FD96B0037 for ; Sun, 13 Oct 2013 15:51:16 -0400 (EDT) Received: by mail-pd0-f181.google.com with SMTP id g10so6467811pdj.26 for ; Sun, 13 Oct 2013 12:51:16 -0700 (PDT) Received: by mail-qa0-f52.google.com with SMTP id w8so1740849qac.11 for ; Sun, 13 Oct 2013 12:51:14 -0700 (PDT) Date: Sun, 13 Oct 2013 15:51:11 -0400 From: Tejun Heo Subject: Re: [RFC 08/23] mm/memblock: debug: don't free reserved array if !ARCH_DISCARD_MEMBLOCK Message-ID: <20131013195111.GB18075@htj.dyndns.org> References: <1381615146-20342-1-git-send-email-santosh.shilimkar@ti.com> <1381615146-20342-9-git-send-email-santosh.shilimkar@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1381615146-20342-9-git-send-email-santosh.shilimkar@ti.com> Sender: owner-linux-mm@kvack.org List-ID: To: Santosh Shilimkar 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 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. > + 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? Thanks. -- tejun -- 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