From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965905AbdIYTdw (ORCPT ); Mon, 25 Sep 2017 15:33:52 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:36886 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936107AbdIYTdb (ORCPT ); Mon, 25 Sep 2017 15:33:31 -0400 X-Google-Smtp-Source: AOwi7QDKqFTyZDIj0lhjaNF/o/OLNyetfcwQYBvp+foV9hYWQ5gSOCORhECywvQWdinxDf88Y2j57w== From: Timofey Titovets To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, borntraeger@de.ibm.com, kvm@vger.kernel.org, Timofey Titovets Subject: [PATCH v3 1/2] xxHash: create arch dependent 32/64-bit xxhash() Date: Mon, 25 Sep 2017 22:33:19 +0300 Message-Id: <20170925193320.10009-2-nefelim4ag@gmail.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170925193320.10009-1-nefelim4ag@gmail.com> References: <20170925193320.10009-1-nefelim4ag@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org xxh32() - fast on both 32/64-bit platforms xxh64() - fast only on 64-bit platform Create xxhash() which will pickup fastest version on compile time. As result depends on cpu word size, the main proporse of that - in memory hashing. Signed-off-by: Timofey Titovets Acked-by: Andi Kleen Acked-by: Christian Borntraeger Cc: Linux-kernel Cc: Linux-kvm --- include/linux/xxhash.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/include/linux/xxhash.h b/include/linux/xxhash.h index 9e1f42cb57e9..2a04ee5c5219 100644 --- a/include/linux/xxhash.h +++ b/include/linux/xxhash.h @@ -107,6 +107,29 @@ uint32_t xxh32(const void *input, size_t length, uint32_t seed); */ uint64_t xxh64(const void *input, size_t length, uint64_t seed); +/** + * xxhash() - calculate wordsize hash of the input with a given seed + * @input: The data to hash. + * @length: The length of the data to hash. + * @seed: The seed can be used to alter the result predictably. + * + * If the hash does not need to be comparable between machines with + * different word sizes, this function will call whichever of xxh32() + * or xxh64() is faster. + * + * Return: wordsize hash of the data. + */ + +static inline unsigned long xxhash(const void *input, size_t length, + uint64_t seed) +{ +#if BITS_PER_LONG == 64 + return xxh64(input, length, seed); +#else + return xxh32(input, length, seed); +#endif +} + /*-**************************** * Streaming Hash Functions *****************************/ -- 2.14.1