From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH v7 09/16] SUNRPC/cache: use new hashtable implementation Date: Mon, 29 Oct 2012 09:27:58 -0700 Message-ID: <20121029092758.1ab87d79.akpm@linux-foundation.org> References: <1351450948-15618-1-git-send-email-levinsasha928@gmail.com> <1351450948-15618-9-git-send-email-levinsasha928@gmail.com> <20121029124229.GC11733@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dev-bounces-yBygre7rU0TnMu66kgdUjQ@public.gmane.org Errors-To: dev-bounces-yBygre7rU0TnMu66kgdUjQ@public.gmane.org To: Linus Torvalds Cc: snitzer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, neilb-l3A5Bk7waGM@public.gmane.org, fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Trond.Myklebust-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org, bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org, paul.gortmaker-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, agk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, aarcange-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, rds-devel-N0ozoZBvEnrZJqsBc5GL+g@public.gmane.org, eric.dumazet-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, venkat.x.venkatsubra-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, ccaulfie-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, mingo-X9Un+BFzKDI@public.gmane.org, dev-yBygre7rU0TnMu66kgdUjQ@public.gmane.org, ericvh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org, rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org, lw-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org, Mathieu Desnoyers , Sasha Levin , axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, edumazet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ejt-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, teigland-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org List-Id: dm-devel.ids On Mon, 29 Oct 2012 07:49:42 -0700 Linus Torvalds wrote: > Because there's no reason to believe that '9' is in any way a worse > random number than something page-shift-related, is there? 9 is much better than PAGE_SHIFT. PAGE_SIZE can vary by a factor of 16, depending on config. Everyone thinks 4k, and tests only for that. There's potential for very large performance and behavior changes when their code gets run on a 64k PAGE_SIZE machine. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail.linuxfoundation.org ([140.211.169.12]:58998 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932647Ab2J2Q2O (ORCPT ); Mon, 29 Oct 2012 12:28:14 -0400 Date: Mon, 29 Oct 2012 09:27:58 -0700 From: Andrew Morton To: Linus Torvalds Cc: Mathieu Desnoyers , Sasha Levin , tj@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, paul.gortmaker@windriver.com, davem@davemloft.net, rostedt@goodmis.org, mingo@elte.hu, ebiederm@xmission.com, aarcange@redhat.com, ericvh@gmail.com, netdev@vger.kernel.org, josh@joshtriplett.org, eric.dumazet@gmail.com, axboe@kernel.dk, agk@redhat.com, dm-devel@redhat.com, neilb@suse.de, ccaulfie@redhat.com, teigland@redhat.com, Trond.Myklebust@netapp.com, bfields@fieldses.org, fweisbec@gmail.com, jesse@nicira.com, venkat.x.venkatsubra@oracle.com, ejt@redhat.com, snitzer@redhat.com, edumazet@google.com, linux-nfs@vger.kernel.org, dev@openvswitch.org, rds-devel@oss.oracle.com, lw@cn.fujitsu.com Subject: Re: [PATCH v7 09/16] SUNRPC/cache: use new hashtable implementation Message-Id: <20121029092758.1ab87d79.akpm@linux-foundation.org> In-Reply-To: References: <1351450948-15618-1-git-send-email-levinsasha928@gmail.com> <1351450948-15618-9-git-send-email-levinsasha928@gmail.com> <20121029124229.GC11733@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, 29 Oct 2012 07:49:42 -0700 Linus Torvalds wrote: > Because there's no reason to believe that '9' is in any way a worse > random number than something page-shift-related, is there? 9 is much better than PAGE_SHIFT. PAGE_SIZE can vary by a factor of 16, depending on config. Everyone thinks 4k, and tests only for that. There's potential for very large performance and behavior changes when their code gets run on a 64k PAGE_SIZE machine. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx200.postini.com [74.125.245.200]) by kanga.kvack.org (Postfix) with SMTP id 5FD2D6B005A for ; Mon, 29 Oct 2012 12:28:13 -0400 (EDT) Date: Mon, 29 Oct 2012 09:27:58 -0700 From: Andrew Morton Subject: Re: [PATCH v7 09/16] SUNRPC/cache: use new hashtable implementation Message-Id: <20121029092758.1ab87d79.akpm@linux-foundation.org> In-Reply-To: References: <1351450948-15618-1-git-send-email-levinsasha928@gmail.com> <1351450948-15618-9-git-send-email-levinsasha928@gmail.com> <20121029124229.GC11733@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds Cc: Mathieu Desnoyers , Sasha Levin , tj@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, paul.gortmaker@windriver.com, davem@davemloft.net, rostedt@goodmis.org, mingo@elte.hu, ebiederm@xmission.com, aarcange@redhat.com, ericvh@gmail.com, netdev@vger.kernel.org, josh@joshtriplett.org, eric.dumazet@gmail.com, axboe@kernel.dk, agk@redhat.com, dm-devel@redhat.com, neilb@suse.de, ccaulfie@redhat.com, teigland@redhat.com, Trond.Myklebust@netapp.com, bfields@fieldses.org, fweisbec@gmail.com, jesse@nicira.com, venkat.x.venkatsubra@oracle.com, ejt@redhat.com, snitzer@redhat.com, edumazet@google.com, linux-nfs@vger.kernel.org, dev@openvswitch.org, rds-devel@oss.oracle.com, lw@cn.fujitsu.com On Mon, 29 Oct 2012 07:49:42 -0700 Linus Torvalds wrote: > Because there's no reason to believe that '9' is in any way a worse > random number than something page-shift-related, is there? 9 is much better than PAGE_SHIFT. PAGE_SIZE can vary by a factor of 16, depending on config. Everyone thinks 4k, and tests only for that. There's potential for very large performance and behavior changes when their code gets run on a 64k PAGE_SIZE machine. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org