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[209.132.180.67]) by mx.google.com with ESMTP id m63-v6si2375634pld.62.2018.09.05.10.13.20; Wed, 05 Sep 2018 10:13:36 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@amazonses.com header.s=ug7nbtf4gccmlpwj322ax3p6ow6yfsug header.b=JQsJWU1k; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727572AbeIEVm6 (ORCPT + 99 others); Wed, 5 Sep 2018 17:42:58 -0400 Received: from a9-46.smtp-out.amazonses.com ([54.240.9.46]:37230 "EHLO a9-46.smtp-out.amazonses.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726487AbeIEVm6 (ORCPT ); Wed, 5 Sep 2018 17:42:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=ug7nbtf4gccmlpwj322ax3p6ow6yfsug; d=amazonses.com; t=1536167512; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:MIME-Version:Content-Type:Feedback-ID; bh=HlPMdYzuRFwlmhRCbXgfEV9PEsQ+OuqBE/q9jclQhT8=; b=JQsJWU1kczWZDFTCLE7jG1nXe4eoI8BFZnFyW4JtMeDT32c+3FufXyhC4RRZPWFl 5ko6B/dNTdeDkpeIoG9hA3LZk3SZd494UsAR12QnNKkIuwrCQPlej4hK6scwwAg/4jG ZGfszY/jAH+a5zEertxgwOaL5HWqkcTThgFz3vEs= Date: Wed, 5 Sep 2018 17:11:52 +0000 From: Christopher Lameter X-X-Sender: cl@nuc-kabylake To: Laurent Dufour cc: Daniel Jordan , linux-kernel@vger.kernel.org, "linux-mm@kvack.org" , Aaron Lu , alex.kogan@oracle.com, akpm@linux-foundation.org, boqun.feng@gmail.com, brouer@redhat.com, dave@stgolabs.net, dave.dice@oracle.com, Dhaval Giani , ktkhai@virtuozzo.com, Pavel.Tatashin@microsoft.com, paulmck@linux.vnet.ibm.com, shady.issa@oracle.com, tariqt@mellanox.com, tglx@linutronix.de, tim.c.chen@intel.com, vbabka@suse.cz, longman@redhat.com, yang.shi@linux.alibaba.com, shy828301@gmail.com, Huang Ying , subhra.mazumdar@oracle.com, Steven Sistare , jwadams@google.com, ashwinch@google.com, sqazi@google.com, Shakeel Butt , walken@google.com, rientjes@google.com, junaids@google.com, Neha Agarwal Subject: Re: Plumbers 2018 - Performance and Scalability Microconference In-Reply-To: <839e2703-1588-0873-00a7-d04810f403cf@linux.vnet.ibm.com> Message-ID: <01000165aab80769-ad7aaedf-81ae-4bbb-a602-a2aa5d49f54e-000000@email.amazonses.com> References: <1dc80ff6-f53f-ae89-be29-3408bf7d69cc@oracle.com> <01000165aa490dc9-64abf872-afd1-4a81-a46d-a50d0131de93-000000@email.amazonses.com> <839e2703-1588-0873-00a7-d04810f403cf@linux.vnet.ibm.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-SES-Outgoing: 2018.09.05-54.240.9.46 Feedback-ID: 1.us-east-1.fQZZZ0Xtj2+TD7V5apTT/NrT6QKuPgzCT/IC7XYgDKI=:AmazonSES Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 5 Sep 2018, Laurent Dufour wrote: > > Large page sizes also reduce contention there. > > That's true for the page fault path, but for process's actions manipulating the > memory process's layout (mmap,munmap,madvise,mprotect) the impact is minimal > unless the code has to manipulate the page tables. Well if you compare having to operate on 4k instead of 64k then the impact is 16xs for larger memory ranges. For smaller operations this may not be that significant. But then I thought we were talking about large areas of memory.