From patchwork Sun Aug 19 00:52:22 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 178519 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id D931E2C007C for ; Sun, 19 Aug 2012 10:57:25 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753330Ab2HSAxn (ORCPT ); Sat, 18 Aug 2012 20:53:43 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:33310 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752170Ab2HSAw2 (ORCPT ); Sat, 18 Aug 2012 20:52:28 -0400 Received: by mail-bk0-f46.google.com with SMTP id j10so1596919bkw.19 for ; Sat, 18 Aug 2012 17:52:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=kw6lBz7AA9x/JPu3y/9oTy+sWjWjJfE4AGIuM9ndn+4=; b=rcN+5hQ0ocY7JhnNk5iy8FyWFsamJskATOmCX3SETtCDhetM0TG+G1FwjGdu86q4DJ FcCoB0TOoNz31JYzDWcjFAZNhNJqb0OpIHxr6f70+LmiBEx3UMulJSwBtDrMS1s0PNVZ i3Jvt9H7HyAjwI83UXFFzM/Le58fMH6RXfZ0awZoEEs408jHG9TXg1EhWuX4NXX85PPo MhxQjdpDw8kuRzknWOYFjHPfhsnxXu0B5XziJ6Ukb7M5Y2vMnoPgQKD53jnXD+h/LIX6 YuqyMsQTBaSaeem63G5/e+gmRbK3w/VgeVhslX/Gmq4rNm/D9mfjbUbJLCLYs/J6ZcFo B7yw== Received: by 10.204.145.90 with SMTP id c26mr3325136bkv.34.1345337547733; Sat, 18 Aug 2012 17:52:27 -0700 (PDT) Received: from localhost.localdomain (95-89-78-76-dynip.superkabel.de. [95.89.78.76]) by mx.google.com with ESMTPS id c18sm4724437bkv.8.2012.08.18.17.52.25 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 18 Aug 2012 17:52:27 -0700 (PDT) From: Sasha Levin To: torvalds@linux-foundation.org Cc: tj@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, paul.gortmaker@windriver.com, davem@davemloft.net, rostedt@goodmis.org, mingo@elte.hu, ebiederm@xmission.com, aarcange@redhat.com, ericvh@gmail.com, netdev@vger.kernel.org, josh@joshtriplett.org, eric.dumazet@gmail.com, mathieu.desnoyers@efficios.com, axboe@kernel.dk, agk@redhat.com, dm-devel@redhat.com, neilb@suse.de, ccaulfie@redhat.com, teigland@redhat.com, Trond.Myklebust@netapp.com, bfields@fieldses.org, fweisbec@gmail.com, jesse@nicira.com, venkat.x.venkatsubra@oracle.com, ejt@redhat.com, snitzer@redhat.com, edumazet@google.com, linux-nfs@vger.kernel.org, dev@openvswitch.org, rds-devel@oss.oracle.com, lw@cn.fujitsu.com, Sasha Levin Subject: [PATCH v2 08/16] block,elevator: use new hashtable implementation Date: Sun, 19 Aug 2012 02:52:22 +0200 Message-Id: <1345337550-24304-10-git-send-email-levinsasha928@gmail.com> X-Mailer: git-send-email 1.7.8.6 In-Reply-To: <1345337550-24304-1-git-send-email-levinsasha928@gmail.com> References: <1345337550-24304-1-git-send-email-levinsasha928@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Switch elevator to use the new hashtable implementation. This reduces the amount of generic unrelated code in the elevator. This also removes the dymanic allocation of the hash table. The size of the table is constant so there's no point in paying the price of an extra dereference when accessing it. Signed-off-by: Sasha Levin --- block/blk.h | 2 +- block/elevator.c | 23 ++++------------------- include/linux/elevator.h | 5 ++++- 3 files changed, 9 insertions(+), 21 deletions(-) diff --git a/block/blk.h b/block/blk.h index 2a0ea32..5650d48 100644 --- a/block/blk.h +++ b/block/blk.h @@ -61,7 +61,7 @@ static inline void blk_clear_rq_complete(struct request *rq) /* * Internal elevator interface */ -#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) +#define ELV_ON_HASH(rq) hash_hashed(&(rq)->hash) void blk_insert_flush(struct request *rq); void blk_abort_flushes(struct request_queue *q); diff --git a/block/elevator.c b/block/elevator.c index 6a55d41..f462a83 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -46,11 +46,6 @@ static LIST_HEAD(elv_list); /* * Merge hash stuff. */ -static const int elv_hash_shift = 6; -#define ELV_HASH_BLOCK(sec) ((sec) >> 3) -#define ELV_HASH_FN(sec) \ - (hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift)) -#define ELV_HASH_ENTRIES (1 << elv_hash_shift) #define rq_hash_key(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq)) /* @@ -142,7 +137,6 @@ static struct elevator_queue *elevator_alloc(struct request_queue *q, struct elevator_type *e) { struct elevator_queue *eq; - int i; eq = kmalloc_node(sizeof(*eq), GFP_KERNEL | __GFP_ZERO, q->node); if (unlikely(!eq)) @@ -151,14 +145,7 @@ static struct elevator_queue *elevator_alloc(struct request_queue *q, eq->type = e; kobject_init(&eq->kobj, &elv_ktype); mutex_init(&eq->sysfs_lock); - - eq->hash = kmalloc_node(sizeof(struct hlist_head) * ELV_HASH_ENTRIES, - GFP_KERNEL, q->node); - if (!eq->hash) - goto err; - - for (i = 0; i < ELV_HASH_ENTRIES; i++) - INIT_HLIST_HEAD(&eq->hash[i]); + hash_init(eq->hash); return eq; err: @@ -173,7 +160,6 @@ static void elevator_release(struct kobject *kobj) e = container_of(kobj, struct elevator_queue, kobj); elevator_put(e->type); - kfree(e->hash); kfree(e); } @@ -240,7 +226,7 @@ EXPORT_SYMBOL(elevator_exit); static inline void __elv_rqhash_del(struct request *rq) { - hlist_del_init(&rq->hash); + hash_del(&rq->hash); } static void elv_rqhash_del(struct request_queue *q, struct request *rq) @@ -254,7 +240,7 @@ static void elv_rqhash_add(struct request_queue *q, struct request *rq) struct elevator_queue *e = q->elevator; BUG_ON(ELV_ON_HASH(rq)); - hlist_add_head(&rq->hash, &e->hash[ELV_HASH_FN(rq_hash_key(rq))]); + hash_add(e->hash, &rq->hash, rq_hash_key(rq)); } static void elv_rqhash_reposition(struct request_queue *q, struct request *rq) @@ -266,11 +252,10 @@ static void elv_rqhash_reposition(struct request_queue *q, struct request *rq) static struct request *elv_rqhash_find(struct request_queue *q, sector_t offset) { struct elevator_queue *e = q->elevator; - struct hlist_head *hash_list = &e->hash[ELV_HASH_FN(offset)]; struct hlist_node *entry, *next; struct request *rq; - hlist_for_each_entry_safe(rq, entry, next, hash_list, hash) { + hash_for_each_possible_safe(e->hash, rq, entry, next, hash, offset) { BUG_ON(!ELV_ON_HASH(rq)); if (unlikely(!rq_mergeable(rq))) { diff --git a/include/linux/elevator.h b/include/linux/elevator.h index c03af76..20b539c 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -2,6 +2,7 @@ #define _LINUX_ELEVATOR_H #include +#include #ifdef CONFIG_BLOCK @@ -96,6 +97,8 @@ struct elevator_type struct list_head list; }; +#define ELV_HASH_BITS 6 + /* * each queue has an elevator_queue associated with it */ @@ -105,7 +108,7 @@ struct elevator_queue void *elevator_data; struct kobject kobj; struct mutex sysfs_lock; - struct hlist_head *hash; + DEFINE_HASHTABLE(hash, ELV_HASH_BITS); unsigned int registered:1; };