Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759081Ab2HWPsd (ORCPT ); Thu, 23 Aug 2012 11:48:33 -0400 Received: from cantor2.suse.de ([195.135.220.15]:43883 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934124Ab2HWPs3 (ORCPT ); Thu, 23 Aug 2012 11:48:29 -0400 Date: Thu, 23 Aug 2012 17:48:25 +0200 From: Michal Hocko To: wujianguo Cc: tony.luck@intel.com, kay.sievers@vrfy.org, minchan.kim@gmail.com, mgorman@suse.de, Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-ia64@vger.kernel.org, wency@cn.fujitsu.com, akpm@linux-foundation.org, yinghai@kernel.org, liuj97@gmail.com, jiang.liu@huawei.com, qiuxishi@huawei.com, wujianguo@huawei.com, guohanjun@huawei.com, Greg KH Subject: Re: [PATCH] mm/ia64: fix a memory block size bug Message-ID: <20120823154646.GA10789@dhcp22.suse.cz> References: <50330482.4070204@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50330482.4070204@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4884 Lines: 126 [Fixed gregkh email address] On Tue 21-08-12 11:46:10, wujianguo wrote: > From: Jianguo Wu > > Hi all, > I found following definition in include/linux/memory.h, in my IA64 > platform, SECTION_SIZE_BITS is equal to 32, and MIN_MEMORY_BLOCK_SIZE will be 0. > #define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS) OK, so I assume you have CONFIG_FORCE_MAX_ZONEORDER 17 and PAGE_SHIFT 16, right? But even CONFIG_FORCE_MAX_ZONEORDER 16 would be a problem. > Because MIN_MEMORY_BLOCK_SIZE is 32bits, so MIN_MEMORY_BLOCK_SIZE(1 << 32) > will equal to 0. This will cause wrong system memory infomation in sysfs. I think > it should be: > #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS) > I guess the part below is not necessary for the changelog > linux-drf:/sys/devices/system/memory # ll > total 0 > -r--r--r-- 1 root root 65536 Aug 20 02:35 block_size_bytes > drwxr-xr-x 3 root root 0 Aug 20 02:19 memory0 > drwxr-xr-x 2 root root 0 Aug 20 02:35 power > -rw-r--r-- 1 root root 65536 Aug 20 02:35 uevent > > linux-drf:/sys/devices/system/memory # cat block_size_bytes > 0 > > linux-drf:/sys/devices/system/memory/memory0 # cat * > 8000000000000000 > cat: node0: Is a directory > cat: node1: Is a directory > cat: node2: Is a directory > cat: node3: Is a directory > 0 > 8000000000000000 > cat: power: Is a directory > 1 > online > cat: subsystem: Is a directory > Up to here. > And "echo offline > memory0/state" will cause following call trace: > > kernel BUG at mm/memory_hotplug.c:885! > sh[6455]: bugcheck! 0 [1] > > Pid: 6455, CPU 0, comm: sh > psr : 0000101008526030 ifs : 8000000000000fa4 ip : [] Not tainted (3.6.0-rc1) > ip is at offline_pages+0x210/0xee0 > unat: 0000000000000000 pfs : 0000000000000fa4 rsc : 0000000000000003 > rnat: a0000001008f2d50 bsps: 0000000000000000 pr : 65519a96659a9565 > ldrs: 0000000000000000 ccv : 0000010b9263f310 fpsr: 0009804c0270033f > csd : 0000000000000000 ssd : 0000000000000000 > b0 : a0000001008c40f0 b6 : a000000100473980 b7 : a0000001000106d0 > f6 : 000000000000000000000 f7 : 1003e0000000085c9354c > f8 : 1003e0044b82fa09b5a53 f9 : 1003e000000d65cd62abf > f10 : 1003efd02efdec682803d f11 : 1003e0000000000000042 > r1 : a00000010152c2e0 r2 : 0000000000006ada r3 : 000000000000fffe > r8 : 0000000000000026 r9 : a00000010121cc18 r10 : a0000001013309f0 > r11 : 65519a96659a19e9 r12 : e00000070a91fdf0 r13 : e00000070a910000 > r14 : 0000000000006ada r15 : 0000000000004000 r16 : 000000006ad8356c > r17 : a0000001019a525e r18 : 0000000000007fff r19 : 0000000000000000 > r20 : 0000000000006ad6 r21 : 0000000000006ad6 r22 : a00000010133bec8 > r23 : 0000000000006ad4 r24 : 0000000000000002 r25 : 8200000000260038 > r26 : 00000000000004f9 r27 : 00000000000004f8 r28 : 000000000001cf98 > r29 : 0000000000000038 r30 : a0000001019a5ae0 r31 : 000000000001cf60 > > Call Trace: > [] show_stack+0x80/0xa0 > sp=e00000070a91f9b0 bsp=e00000070a9115e0 > [] show_regs+0x640/0x920 > sp=e00000070a91fb80 bsp=e00000070a911588 > [] die+0x190/0x2c0 > sp=e00000070a91fb90 bsp=e00000070a911548 > [] die_if_kernel+0x50/0x80 > sp=e00000070a91fb90 bsp=e00000070a911518 > [] ia64_bad_break+0x3d0/0x6e0 > sp=e00000070a91fb90 bsp=e00000070a9114f0 > [] ia64_native_leave_kernel+0x0/0x270 > sp=e00000070a91fc20 bsp=e00000070a9114f0 > [] offline_pages+0x210/0xee0 > sp=e00000070a91fdf0 bsp=e00000070a9113c8 > [] alloc_pages_current+0x180/0x2a0 > sp=e00000070a91fe20 bsp=e00000070a9113a > > This patch is trying to fix the bug. not just trying ;) > > Signed-off-by: Jianguo Wu Reviewed-by: Michal Hocko > --- > include/linux/memory.h | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/include/linux/memory.h b/include/linux/memory.h > index 1ac7f6e..ff9a9f8 100644 > --- a/include/linux/memory.h > +++ b/include/linux/memory.h > @@ -19,7 +19,7 @@ > #include > #include > > -#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS) > +#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS) > > struct memory_block { > unsigned long start_section_nr; -- Michal Hocko SUSE Labs -- 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/