From patchwork Fri Sep 21 17:17:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Yipeng1" X-Patchwork-Id: 45148 Return-Path: X-Original-To: patchwork@dpdk.org Delivered-To: patchwork@dpdk.org Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 0C2584C95; Sat, 22 Sep 2018 02:22:13 +0200 (CEST) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id A48F1A49 for ; Sat, 22 Sep 2018 02:22:11 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Sep 2018 17:22:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,287,1534834800"; d="scan'208";a="76346596" Received: from skx-yipeng.jf.intel.com ([10.54.81.175]) by orsmga006.jf.intel.com with ESMTP; 21 Sep 2018 17:22:10 -0700 From: Yipeng Wang To: bruce.richardson@intel.com Cc: dev@dpdk.org, yipeng1.wang@intel.com, michel@digirati.com.br, honnappa.nagarahalli@arm.com Date: Fri, 21 Sep 2018 10:17:28 -0700 Message-Id: <1537550255-252066-1-git-send-email-yipeng1.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1536253745-133104-1-git-send-email-yipeng1.wang@intel.com> References: <1536253745-133104-1-git-send-email-yipeng1.wang@intel.com> Subject: [dpdk-dev] [PATCH v2 0/7] hash: add extendable bucket and partial key hashing 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" The first four commits of the patch set try to fix small issues of previous code. The other commits make two major optimizations over the current rte_hash library. First, it adds Extendable Bucket Table feature: a new structure that can accommodate keys that failed to get inserted into the main hash table due to the unlikely event of excessive hash collisions. The hash table buckets will get extended using a linked list to host these keys. This new design will guarantee insertion of 100% of the keys for a given hash table size with minimal overhead. A new flag value is added for user to indicate if the extendable bucket feature should be enabled or not. The linked list buckets is similar concept to the extendable bucket hash table in packet framework. In details, for insertion, the linked buckets will be used to store the keys that fail to get in the primary and the secondary bucket and the cuckoo path could not find an empty location for the maximum path length (small probability). For lookup, the key is checked first in the primary, then the secondary, then if the secondary is extended the linked list is traversed for a possible match. Second, the patch set changes the current hashing algorithm to be "partial-key hashing". Partial-key hashing is the concept from Bin Fan, et al.'s paper "MemC3: Compact and Concurrent MemCache with Dumber Caching and Smarter Hashing". Instead of storing both 32-bit signature and alternative signature in the bucket, we only store a small 16-bit signature and calculate the alternative bucket index by XORing the signature with the current bucket index. This doubles the hash table memory efficiency since now one bucket only occupies one cache line instead of two in the original design. V1->V2: 1. hash: Rewrite rte_hash_get_last_bkt to be more concise. 2. hash: Reorder the rte_hash struct to align cache line better. 3. test: Minor changes in auto test to add key insertion failure check during iteration test. 4. test: Add new commit to fix read-write test non-consecutive core issue. 4. hash: Add a new commit to remove unnecessary code introduced by previous patches. 5. hash: Comments improvement and coding style improvements over multiple places. Signed-off-by: Yipeng Wang Yipeng Wang (7): test/hash: fix bucket size in hash perf test test/hash: more accurate hash perf test output test/hash: fix rw test with non-consecutive cores hash: fix unnecessary code hash: add extendable bucket feature test/hash: implement extendable bucket hash test hash: use partial-key hashing lib/librte_hash/rte_cuckoo_hash.c | 516 +++++++++++++++++++++++++++----------- lib/librte_hash/rte_cuckoo_hash.h | 13 +- lib/librte_hash/rte_hash.h | 8 +- test/test/test_hash.c | 151 ++++++++++- test/test/test_hash_perf.c | 126 +++++++--- test/test/test_hash_readwrite.c | 78 +++--- 6 files changed, 672 insertions(+), 220 deletions(-)