From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from e06smtp16.uk.ibm.com ([195.75.94.112]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YV0F2-00034S-Bh for kexec@lists.infradead.org; Mon, 09 Mar 2015 16:09:17 +0000 Received: from /spool/local by e06smtp16.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 9 Mar 2015 16:08:51 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id B998E17D8059 for ; Mon, 9 Mar 2015 16:09:09 +0000 (GMT) Received: from d06av11.portsmouth.uk.ibm.com (d06av11.portsmouth.uk.ibm.com [9.149.37.252]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t29G8mU59502978 for ; Mon, 9 Mar 2015 16:08:48 GMT Received: from d06av11.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av11.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t29G8kSw019495 for ; Mon, 9 Mar 2015 10:08:47 -0600 Date: Mon, 9 Mar 2015 17:08:44 +0100 From: Michael Holzheu Subject: Re: [PATCH v2 0/8] Handle mmaped regions in cache Message-ID: <20150309170844.69b6d139@holzheu> In-Reply-To: References: 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=infradead.org@lists.infradead.org To: Petr Tesarik Cc: kexec mailing list , Atsushi Kumagai , Jan Willeke Hello Petr, With your patch we get 5-10 percent performance improvement on s390. Two examples: $ time ./makedumpfile -d 31 /proc/vmcore /dev/null -f user sys = total ===================================== With patches 0.156 0.248 0.404 Without patches 0.168 0.274 0.442 <- No idea why we save system time? $ time ./makedumpfile -d 0 /proc/vmcore /dev/null -f user sys = total ===================================== With patches 0.683 0.020 0.703 Without patches 0.714 0.019 0.733 Regards Michael On Fri, 6 Mar 2015 15:03:12 +0100 Petr Tesarik wrote: > Because all pages must go into the cache, data is unnecessarily > copied from mmapped regions to cache. Avoid this copying by storing > the mmapped regions directly in the cache. > > First, the cache code needs a clean up clarification of the concept, > especially the meaning of the pending list (allocated cache entries > whose content is not yet valid). > > Second, the cache must be able to handle differently sized objects > so that it can store individual pages as well as mmapped regions. > > Last, the cache eviction code must be extended to allow either > reusing the read buffer or unmapping the region. > > Changelog: > v2: cache cleanup _and_ actuall mmap implementation > v1: only the cache cleanup > > Petr Tesarik (8): > cache: get rid of search loop in cache_add() > cache: allow to return a page to the pool > cache: do not allocate from the pending list > cache: add hit/miss statistics to the final report > cache: allocate buffers in one big chunk > cache: allow arbitrary size of cache entries > cache: store mapped regions directly in the cache > cleanup: remove unused page_is_fractional > > cache.c | 81 +++++++++++++++++---------------- > cache.h | 16 +++++-- > elf_info.c | 16 ------- > elf_info.h | 2 - > makedumpfile.c | 138 ++++++++++++++++++++++++++++++++++----------------------- > 5 files changed, 138 insertions(+), 115 deletions(-) > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec