From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VmEh0-00070d-OS for kexec@lists.infradead.org; Fri, 29 Nov 2013 03:24:36 +0000 Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 8A3403EE164 for ; Fri, 29 Nov 2013 12:24:08 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 733C245DE5C for ; Fri, 29 Nov 2013 12:24:08 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.nic.fujitsu.com [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 4F86645DE55 for ; Fri, 29 Nov 2013 12:24:08 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 2A864E18011 for ; Fri, 29 Nov 2013 12:24:08 +0900 (JST) Received: from m1000.s.css.fujitsu.com (m1000.s.css.fujitsu.com [10.240.81.136]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id CF8671DB8043 for ; Fri, 29 Nov 2013 12:24:07 +0900 (JST) Message-ID: <5298084B.7060603@jp.fujitsu.com> Date: Fri, 29 Nov 2013 12:21:47 +0900 From: HATAYAMA Daisuke MIME-Version: 1.0 Subject: Re: [PATCH 0/3] makedumpfile: hugepage filtering for vmcore dump References: <0910DD04CBD6DE4193FCF86B9C00BE971C855E@BPXM01GP.gisp.nec.co.jp> In-Reply-To: <0910DD04CBD6DE4193FCF86B9C00BE971C855E@BPXM01GP.gisp.nec.co.jp> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Atsushi Kumagai Cc: "bhe@redhat.com" , "tom.vaden@hp.com" , "kexec@lists.infradead.org" , "ptesarik@suse.cz" , "linux-kernel@vger.kernel.org" , "lisa.mitchell@hp.com" , "vgoyal@redhat.com" , "anderson@redhat.com" , "ebiederm@xmission.com" , "jingbai.ma@hp.com" (2013/11/29 12:02), Atsushi Kumagai wrote: > On 2013/11/28 16:50:21, kexec wrote: >>>> ping, in case you overlooked this... >>> >>> Sorry for the delayed response, I prioritize the release of v1.5.5 now. >>> >>> Thanks for your advice, check_cyclic_buffer_overrun() should be fixed >>> as you said. In addition, I'm considering other way to address such case, >>> that is to bring the number of "overflowed pages" to the next cycle and >>> exclude them at the top of __exclude_unnecessary_pages() like below: >>> >>> /* >>> * The pages which should be excluded still remain. >>> */ >>> if (remainder >= 1) { >>> int i; >>> unsigned long tmp; >>> for (i = 0; i < remainder; ++i) { >>> if (clear_bit_on_2nd_bitmap_for_kernel(pfn + i)) { >>> pfn_user++; >>> tmp++; >>> } >>> } >>> pfn += tmp; >>> remainder -= tmp; >>> mem_map += (tmp - 1) * SIZE(page); >>> continue; >>> } >>> >>> If this way works well, then aligning info->buf_size_cyclic will be >>> unnecessary. >>> >> >> I selected the current implementation of changing cyclic buffer size becuase >> I thought it was simpler than carrying over remaining filtered pages to next cycle >> in that there was no need to add extra code in filtering processing. >> >> I guess the reason why you think this is better now is how to detect maximum order of >> huge page is hard in some way, right? > > The maximum order will be gotten from HUGETLB_PAGE_ORDER or HPAGE_PMD_ORDER, > so I don't say it's hard. However, the carrying over method doesn't depend on > such kernel symbols, so I think it's robuster. > Then, it's better to remove check_cyclic_buffer_overrun() and rewrite part of free page filtering in __exclude_unnecessary_pages(). Could you do that too? -- Thanks. HATAYAMA, Daisuke _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec