From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH v3 01/17] hashtable: introduce a small and naive hashtable Date: Fri, 24 Aug 2012 13:33:32 -0700 Message-ID: <20120824203332.GF21325@google.com> References: <1345602432-27673-1-git-send-email-levinsasha928@gmail.com> <1345602432-27673-2-git-send-email-levinsasha928@gmail.com> <20120822180138.GA19212@google.com> <50357840.5020201@gmail.com> <20120823200456.GD14962@google.com> <5037DA47.9010306@gmail.com> <20120824195941.GC21325@google.com> <5037E00B.6090606@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <5037E00B.6090606-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> 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: Sasha Levin 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, mathieu.desnoyers-vg+e7yoeK/dWk0Htik3J/w@public.gmane.org, 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, lw-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org, teigland-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org List-Id: dm-devel.ids Hello, Sasha. On Fri, Aug 24, 2012 at 10:11:55PM +0200, Sasha Levin wrote: > > If this implementation is about the common trivial case, why not just > > have the usual DECLARE/DEFINE_HASHTABLE() combination? > > When we add the dynamic non-resizable support, how would DEFINE_HASHTABLE() look? Hmmm? DECLARE/DEFINE are usually for static ones. > > I don't know. If we stick to the static (or even !resize dymaic) > > straight-forward hash - and we need something like that - I don't see > > what the full encapsulation buys us other than a lot of trivial > > wrappers. > > Which macros do you consider as trivial within the current API? > > Basically this entire thing could be reduced to DEFINE/DECLARE_HASHTABLE and > get_bucket(), but it would make the life of anyone who wants a slightly > different hashtable a hell. Wouldn't the following be enough to get most of the benefits? * DECLARE/DEFINE * hash_head() * hash_for_each_head() * hash_add*() * hash_for_each_possible*() > I think that right now the only real trivial wrapper is hash_hashed(), and I > think it's a price worth paying to have a single hashtable API instead of > fragmenting it when more implementations come along. I'm not objecting strongly against full encapsulation but having this many thin wrappers makes me scratch my head. Thanks. -- tejun From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-pb0-f46.google.com ([209.85.160.46]:41160 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753539Ab2HXUdk (ORCPT ); Fri, 24 Aug 2012 16:33:40 -0400 Date: Fri, 24 Aug 2012 13:33:32 -0700 From: Tejun Heo To: Sasha Levin Cc: torvalds@linux-foundation.org, akpm@linux-foundation.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, mathieu.desnoyers@efficios.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 v3 01/17] hashtable: introduce a small and naive hashtable Message-ID: <20120824203332.GF21325@google.com> References: <1345602432-27673-1-git-send-email-levinsasha928@gmail.com> <1345602432-27673-2-git-send-email-levinsasha928@gmail.com> <20120822180138.GA19212@google.com> <50357840.5020201@gmail.com> <20120823200456.GD14962@google.com> <5037DA47.9010306@gmail.com> <20120824195941.GC21325@google.com> <5037E00B.6090606@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <5037E00B.6090606@gmail.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Hello, Sasha. On Fri, Aug 24, 2012 at 10:11:55PM +0200, Sasha Levin wrote: > > If this implementation is about the common trivial case, why not just > > have the usual DECLARE/DEFINE_HASHTABLE() combination? > > When we add the dynamic non-resizable support, how would DEFINE_HASHTABLE() look? Hmmm? DECLARE/DEFINE are usually for static ones. > > I don't know. If we stick to the static (or even !resize dymaic) > > straight-forward hash - and we need something like that - I don't see > > what the full encapsulation buys us other than a lot of trivial > > wrappers. > > Which macros do you consider as trivial within the current API? > > Basically this entire thing could be reduced to DEFINE/DECLARE_HASHTABLE and > get_bucket(), but it would make the life of anyone who wants a slightly > different hashtable a hell. Wouldn't the following be enough to get most of the benefits? * DECLARE/DEFINE * hash_head() * hash_for_each_head() * hash_add*() * hash_for_each_possible*() > I think that right now the only real trivial wrapper is hash_hashed(), and I > think it's a price worth paying to have a single hashtable API instead of > fragmenting it when more implementations come along. I'm not objecting strongly against full encapsulation but having this many thin wrappers makes me scratch my head. Thanks. -- tejun From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx109.postini.com [74.125.245.109]) by kanga.kvack.org (Postfix) with SMTP id 0427F6B002B for ; Fri, 24 Aug 2012 16:33:40 -0400 (EDT) Received: by pbbro12 with SMTP id ro12so4479143pbb.14 for ; Fri, 24 Aug 2012 13:33:40 -0700 (PDT) Date: Fri, 24 Aug 2012 13:33:32 -0700 From: Tejun Heo Subject: Re: [PATCH v3 01/17] hashtable: introduce a small and naive hashtable Message-ID: <20120824203332.GF21325@google.com> References: <1345602432-27673-1-git-send-email-levinsasha928@gmail.com> <1345602432-27673-2-git-send-email-levinsasha928@gmail.com> <20120822180138.GA19212@google.com> <50357840.5020201@gmail.com> <20120823200456.GD14962@google.com> <5037DA47.9010306@gmail.com> <20120824195941.GC21325@google.com> <5037E00B.6090606@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5037E00B.6090606@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: torvalds@linux-foundation.org, akpm@linux-foundation.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, mathieu.desnoyers@efficios.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 Hello, Sasha. On Fri, Aug 24, 2012 at 10:11:55PM +0200, Sasha Levin wrote: > > If this implementation is about the common trivial case, why not just > > have the usual DECLARE/DEFINE_HASHTABLE() combination? > > When we add the dynamic non-resizable support, how would DEFINE_HASHTABLE() look? Hmmm? DECLARE/DEFINE are usually for static ones. > > I don't know. If we stick to the static (or even !resize dymaic) > > straight-forward hash - and we need something like that - I don't see > > what the full encapsulation buys us other than a lot of trivial > > wrappers. > > Which macros do you consider as trivial within the current API? > > Basically this entire thing could be reduced to DEFINE/DECLARE_HASHTABLE and > get_bucket(), but it would make the life of anyone who wants a slightly > different hashtable a hell. Wouldn't the following be enough to get most of the benefits? * DECLARE/DEFINE * hash_head() * hash_for_each_head() * hash_add*() * hash_for_each_possible*() > I think that right now the only real trivial wrapper is hash_hashed(), and I > think it's a price worth paying to have a single hashtable API instead of > fragmenting it when more implementations come along. I'm not objecting strongly against full encapsulation but having this many thin wrappers makes me scratch my head. Thanks. -- tejun -- 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