From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50502) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a4KjC-0005Fy-Hg for qemu-devel@nongnu.org; Wed, 02 Dec 2015 22:38:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a4Kj9-0006cv-Ak for qemu-devel@nongnu.org; Wed, 02 Dec 2015 22:38:42 -0500 Received: from [59.151.112.132] (port=49406 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a4Kj8-0006c4-L2 for qemu-devel@nongnu.org; Wed, 02 Dec 2015 22:38:39 -0500 References: <1448627251-11186-1-git-send-email-zhangchen.fnst@cn.fujitsu.com> <1448627251-11186-3-git-send-email-zhangchen.fnst@cn.fujitsu.com> <20151201112322.GB26419@work-vm> From: Zhang Chen Message-ID: <565FB9A0.7080303@cn.fujitsu.com> Date: Thu, 3 Dec 2015 11:40:16 +0800 MIME-Version: 1.0 In-Reply-To: <20151201112322.GB26419@work-vm> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH 2/9] jhash: add linux kernel jhashtable in qemu List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: Li Zhijian , Gui jianfeng , Jason Wang , "eddie.dong" , qemu devel , Huang peng , Gong lei , Stefan Hajnoczi , jan.kiszka@siemens.com, zhanghailiang Hi,Dave On 12/01/2015 07:23 PM, Dr. David Alan Gilbert wrote: > * Zhang Chen (zhangchen.fnst@cn.fujitsu.com) wrote: >> From: zhangchen >> >> This used by colo-proxy to save and lookup >> connection info >> >> Signed-off-by: zhangchen >> --- >> include/qemu/jhash.h | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 52 insertions(+) >> create mode 100644 include/qemu/jhash.h >> >> diff --git a/include/qemu/jhash.h b/include/qemu/jhash.h >> new file mode 100644 >> index 0000000..f6cc7b3 >> --- /dev/null >> +++ b/include/qemu/jhash.h >> @@ -0,0 +1,52 @@ >> +/* >> + * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO) >> + * (a.k.a. Fault Tolerance or Continuous Replication) >> + * >> + * Copyright (c) 2015 HUAWEI TECHNOLOGIES CO., LTD. >> + * Copyright (c) 2015 FUJITSU LIMITED >> + * Copyright (c) 2015 Intel Corporation >> + * >> + * Author: Zhang Chen >> + * >> + * This work is licensed under the terms of the GNU GPL, version 2 or >> + * later. See the COPYING file in the top-level directory. >> + */ > Please be careful with the copyright. > This code is mostly a copy of the kernel code, so I think it should take the copyright > from the kernel code (see kernel's include/linux/jhash.h); and that copyright > states it's based on Bob Jenkins' Public Domain code. > Normally we have a problem as well QEMU doesn't like taking GPL2 code from the kernel, > but my reading of the kernel's header file is that it's still Public domain; but I don't > know what the right thing is to be sure. > > Dave I will remove it and change it to kernel jhash.h's copyright in next version Thanks for review zhangchen >> + >> +#ifndef QEMU_JHASH_H__ >> +#define QEMU_JHASH_H__ >> + >> +/* >> + * hashtable relation copy from linux kernel jhash >> + */ >> +static inline uint32_t rol32(uint32_t word, unsigned int shift) >> +{ >> + return (word << shift) | (word >> (32 - shift)); >> +} >> + >> +/* __jhash_mix -- mix 3 32-bit values reversibly. */ >> +#define __jhash_mix(a, b, c) \ >> +{ \ >> + a -= c; a ^= rol32(c, 4); c += b; \ >> + b -= a; b ^= rol32(a, 6); a += c; \ >> + c -= b; c ^= rol32(b, 8); b += a; \ >> + a -= c; a ^= rol32(c, 16); c += b; \ >> + b -= a; b ^= rol32(a, 19); a += c; \ >> + c -= b; c ^= rol32(b, 4); b += a; \ >> +} >> + >> +/* __jhash_final - final mixing of 3 32-bit values (a,b,c) into c */ >> +#define __jhash_final(a, b, c) \ >> +{ \ >> + c ^= b; c -= rol32(b, 14); \ >> + a ^= c; a -= rol32(c, 11); \ >> + b ^= a; b -= rol32(a, 25); \ >> + c ^= b; c -= rol32(b, 16); \ >> + a ^= c; a -= rol32(c, 4); \ >> + b ^= a; b -= rol32(a, 14); \ >> + c ^= b; c -= rol32(b, 24); \ >> +} >> + >> +/* An arbitrary initial parameter */ >> +#define JHASH_INITVAL 0xdeadbeef >> + >> +#endif /* QEMU_JHASH_H__ */ >> -- >> 1.9.1 >> >> >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > > > . >