From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 39887A0559; Mon, 16 Mar 2020 20:33:00 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 241521C0BD; Mon, 16 Mar 2020 20:32:59 +0100 (CET) Received: from mail-pf1-f196.google.com (mail-pf1-f196.google.com [209.85.210.196]) by dpdk.org (Postfix) with ESMTP id C0A301C06B for ; Mon, 16 Mar 2020 20:32:57 +0100 (CET) Received: by mail-pf1-f196.google.com with SMTP id z5so10517214pfn.5 for ; Mon, 16 Mar 2020 12:32:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=h1WYr4wOb13mAs08o26jcF91BZrlwIovTFTONa41ccs=; b=nY+83mjgHdihi8AVwvlufEbOzNpkXLRT+6qNJ3DCyHTpDDPcDDxx52Ee9YXFAcAMro CVHTpvgKI0dYcc50ga497irtnlN0SPh2/ZZWn/vzuiy5KfZt4aN/SxAA1Ll2i03n8+Te 7XM0+yvdZQ6D26VeJyH3ATD+W+QFcuZ/2OAKABU66SJEZpCKRjsFN9BVqSVHwsgonJPW mTEoitu7Lj/lnpSfItSjGWm+uXKyPqzs3nkJMTiGtWVUhXyKoXkDf0NG0oyRQZxlaIcz /gzU+4FqK1PtQU1t0jUoQ/63CAHJ8wEl7J0PPp5hTQzpGisTr47M/h6HpFxrXA04ge0x GzZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=h1WYr4wOb13mAs08o26jcF91BZrlwIovTFTONa41ccs=; b=OZgHGLEdDjQjOIYriTdoEBzGnRztMksh1PaMmDqf8A1B6gCJaSkORgxsmwuLNNU6AF hMY/PVHe4tj4ipl0AuGj1CUmBvw5EZ0cCzfBiK+jkcup2v03Kn6fyD09RAO4oxruj6sS iEosuJxQm1KEJYt+VJHbCBhS3cwhAwDTOW1l/KF901S0vZZKrZY+GzYXzvycyfUacdpD aaa069WLGbuoiw7JTkHEsBpnPwxeNqXJ3lcybZQyOyY20gUptBww+rWph7vdkfesa6w7 yN685INFpy3v7WM4ZANClODpmJNg4pmVs7QKwRMjDbFs5C7ZTnyLZhI+IzjgoW1AcwqP hNNA== X-Gm-Message-State: ANhLgQ2iLHjXHrEZqrhWTa06TLqnV8d7t1ne/GXrQj60RIc/33w+pZ6o pwFG5ue51q0IMc8Y6cwjYxg6Zw== X-Google-Smtp-Source: ADFU+vvgCiVInzHypSOxqbEki2k1XgCAXMI2TUmzx9ABOxvEa+Chx73N1EnQ1t6C0tvXE8bTjdJxnw== X-Received: by 2002:a62:6842:: with SMTP id d63mr1213755pfc.113.1584387176653; Mon, 16 Mar 2020 12:32:56 -0700 (PDT) Received: from hermes.lan (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id d7sm717416pfr.17.2020.03.16.12.32.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Mar 2020 12:32:56 -0700 (PDT) Date: Mon, 16 Mar 2020 12:32:53 -0700 From: Stephen Hemminger To: "Medvedkin, Vladimir" Cc: Morten =?UTF-8?B?QnLDuHJ1cA==?= , dev@dpdk.org, konstantin.ananyev@intel.com, yipeng1.wang@intel.com, sameh.gobriel@intel.com, bruce.richardson@intel.com, Suanming Mou , Olivier Matz , "Xueming(Steven) Li" , Andrew Rybchenko , Asaf Penso , Ori Kam Message-ID: <20200316123253.7566d799@hermes.lan> In-Reply-To: <2baf9a76-a606-d376-dcce-b95c80fc6bb2@intel.com> References: <98CBD80474FA8B44BF855DF32C47DC35C60ED7@smartserver.smartshare.dk> <2baf9a76-a606-d376-dcce-b95c80fc6bb2@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [dpdk-dev] [PATCH 0/3] add new Double Word Key hash table X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Mon, 16 Mar 2020 18:27:40 +0000 "Medvedkin, Vladimir" wrote: > Hi Morten, >=20 >=20 > On 16/03/2020 14:39, Morten Br=C3=B8rup wrote: > >> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Vladimir Medvedkin > >> Sent: Monday, March 16, 2020 2:38 PM > >> > >> Currently DPDK has a special implementation of a hash table for > >> 4 byte keys which is called FBK hash. Unfortunately its main drawback > >> is that it only supports 2 byte values. > >> The new implementation called DWK (double word key) hash > >> supports 8 byte values, which is enough to store a pointer. > >> > >> It would also be nice to get feedback on whether to leave the old FBK > >> and new DWK implementations, or whether to deprecate the old one? =20 > > > > > > Who comes up with these names?!? > > > > FBK (Four Byte Key) and DWK (Double Word Key) is supposed to mean the s= ame. Could you use 32 somewhere in the name instead, like in int32_t, inste= ad of using a growing list of creative synonyms for the same thing? Pretty = please, with a cherry on top! =20 >=20 >=20 > That's true, at first I named it as fbk2, but then it was decided to=20 > rename it "dwk", so that there was no confusion with the existing FBK=20 > library. Naming suggestions are welcome! >=20 > > > > And if the value size is fixed too, perhaps the name should also indica= te the value size. > > > > > > > > It's a shame we don't have C++ class templates available in DPDK... > > > > In other news, Mellanox has sent an RFC for an "indexed memory pool" li= brary [1] to conserve memory by using uintXX_t instead of pointers, so perh= aps a variant of a 32 bit key hash library with 32 bit values (in addition = to 16 bit values in FBK and 64 bit in DWK) would be nice combination with t= hat library. > > > > [1]: http://mails.dpdk.org/archives/dev/2019-October/147513.html > > > > > > Med venlig hilsen / kind regards > > - Morten Br=C3=B8rup > > =20 Why is this different (or better) than existing rte_hash. Having more flavors is not necessarily a good thing (except in Gelato)