From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by kanga.kvack.org (Postfix) with ESMTP id 8F2FD6B000D for ; Tue, 23 Oct 2018 14:26:26 -0400 (EDT) Received: by mail-wr1-f70.google.com with SMTP id v30-v6so1725091wra.19 for ; Tue, 23 Oct 2018 11:26:26 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id v3-v6sor1635402wrw.43.2018.10.23.11.26.24 for (Google Transport Security); Tue, 23 Oct 2018 11:26:25 -0700 (PDT) From: Timofey Titovets Subject: [PATCH RESEND V8 1/2] xxHash: create arch dependent 32/64-bit xxhash() Date: Tue, 23 Oct 2018 21:25:53 +0300 Message-Id: <20181023182554.23464-2-nefelim4ag@gmail.com> In-Reply-To: <20181023182554.23464-1-nefelim4ag@gmail.com> References: <20181023182554.23464-1-nefelim4ag@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: Timofey Titovets , Andrea Arcangeli , kvm@vger.kernel.org, leesioh 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. Changes: v2: - Create that patch v3 -> v8: - Nothing, whole patchset version bump Signed-off-by: Timofey Titovets Reviewed-by: Pavel Tatashin Reviewed-by: Mike Rapoport CC: Andrea Arcangeli CC: linux-mm@kvack.org CC: kvm@vger.kernel.org CC: leesioh --- include/linux/xxhash.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/include/linux/xxhash.h b/include/linux/xxhash.h index 9e1f42cb57e9..52b073fea17f 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 *****************************/ -- 2.19.0