From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from e06smtp15.uk.ibm.com ([195.75.94.111]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WSTE8-0008CS-Qb for kexec@lists.infradead.org; Tue, 25 Mar 2014 15:25:22 +0000 Received: from /spool/local by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 25 Mar 2014 15:24:57 -0000 Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id D11261B08070 for ; Tue, 25 Mar 2014 15:24:47 +0000 (GMT) Received: from d06av08.portsmouth.uk.ibm.com (d06av08.portsmouth.uk.ibm.com [9.149.37.249]) by b06cxnps3074.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s2PFOhWp459168 for ; Tue, 25 Mar 2014 15:24:43 GMT Received: from d06av08.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av08.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s2PFOsSo029957 for ; Tue, 25 Mar 2014 09:24:54 -0600 Date: Tue, 25 Mar 2014 16:24:52 +0100 From: Michael Holzheu Subject: Re: makedumpfile: get_max_mapnr() from ELF header problem Message-ID: <20140325162452.792f5ad4@holzheu> In-Reply-To: <0910DD04CBD6DE4193FCF86B9C00BE971F909B@BPXM01GP.gisp.nec.co.jp> References: <20140228134148.15b60ceb@holzheu> <531FDF6D.5080901@jp.fujitsu.com> <0910DD04CBD6DE4193FCF86B9C00BE971F512A@BPXM01GP.gisp.nec.co.jp> <20140312171812.02f0bfe1@holzheu> <0910DD04CBD6DE4193FCF86B9C00BE971F672F@BPXM01GP.gisp.nec.co.jp> <20140314151928.5c49f17f@holzheu> <0910DD04CBD6DE4193FCF86B9C00BE971F7B95@BPXM01GP.gisp.nec.co.jp> <20140319180903.2c6e2b72@holzheu> <0910DD04CBD6DE4193FCF86B9C00BE971F909B@BPXM01GP.gisp.nec.co.jp> Mime-Version: 1.0 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: "d.hatayama@jp.fujitsu.com" , "kexec@lists.infradead.org" On Tue, 25 Mar 2014 01:14:21 +0000 Atsushi Kumagai wrote: [snip] > >But it looks like get_mm_sparsemem() does not check for zero. > >The nr_to_section() function just returns an invalid address > >(something between 0 and 4096) for section in case we get zero > >from the "mem_section" entry. This is address is then used for > >calculating "mem_map": > > In other architectures, the check by is_kaddr() avoids to > read invalid address, but it doesn't do anything in the case > of s390 due to the its memory management mechanism: > > s390x: Fix KVBASE to correct value for s390x architecture. > http://lists.infradead.org/pipermail/kexec/2011-March/004930.html Right, for s390 the zero page is valid. > Finally I've understood the cause of this issue completely, > thanks for your report. > > >mem_map = section_mem_map_addr(section); > >mem_map = sparse_decode_mem_map(mem_map, section_nr); > > > >With the patch below I could use makedumpfile (1.5.3) successfully > >on the 1TB dump with mem=1G. I attached the -D output that is > >created by makedumpfile with the patch. > > > >But compared to my first patch it takes much longer and the resulting > >dump is bigger (version 1.5.3): > > > > | Dump time | Dump size > >-------------+-------------+----------- > >First patch | 10 sec | 124 MB > >Second patch | 87 minutes | 6348 MB > > > >No idea why the dump is bigger with the second patch. I think the time > >is consumed in write_kdump_pages_cyclic() by checking for zero pages > >for the whole range: > > I suppose this difference was resolved with the v2 of the second patch, > right? Right, with the last patch the dump time and size were ok. [snip] > >So the first patch would be better for my scenario. What in particular are your > >concerns with that patch? > > I think the v2 second patch is a reasonable patch to fix the > bug of get_mm_sparsemem(). > Additionally, the latest patch you posted to adjust max_mapnr > (which using mem_map_data[]) is acceptable instead of the first > patch. > So could you re-post the two as a formal patch set? > I mean patch descriptions and your signature are needed. Ok great! I will resend the patches. Michael _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec