From patchwork Tue Oct 30 18:46:04 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 1672791 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 937783FD2B for ; Tue, 30 Oct 2012 18:50:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965518Ab2J3Srm (ORCPT ); Tue, 30 Oct 2012 14:47:42 -0400 Received: from mail-qc0-f174.google.com ([209.85.216.174]:46116 "EHLO mail-qc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965249Ab2J3Srk (ORCPT ); Tue, 30 Oct 2012 14:47:40 -0400 Received: by mail-qc0-f174.google.com with SMTP id o22so398523qcr.19 for ; Tue, 30 Oct 2012 11:47:39 -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=NeLhqtpga9CfaVOcKqLIXGSelB6ZLgr5VN6Mj5Qj2/M=; b=TlSzIHQaK6Up/2xZuKJ4x8GiF3ONEncLL2dSo5QMohsDTj2P8qNholVwMc40b8UONm FeBZqxLGn6+LmMJW12tgyN6w0NAe/ZGgMG1Ufm+iJKEqKhY/KdMH4M2D9xw826Vn/Y4t CKzneO01vQr9QugmNw92v8TFV7TLKcLWzL/RvEcG0cbThxo7u1PZyXZV2nrMO0SGW/3u 17GUltE5O9Vme21+w7Az3XT+sMrE2KPjWVB/DSBNTkee0wdKuRTuKRcO4HDgEX5wwWbQ U8Yo+/yEJd6uhGkm95lneaRsi+mQ//odCPypFCe26xhcWVQQwh7f3NJqk3dtmgYiWwoC jfew== Received: by 10.224.60.17 with SMTP id n17mr22009566qah.63.1351622859864; Tue, 30 Oct 2012 11:47:39 -0700 (PDT) Received: from localhost.localdomain ([50.145.164.180]) by mx.google.com with ESMTPS id ga9sm682790qab.22.2012.10.30.11.47.34 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 30 Oct 2012 11:47:39 -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 v8 08/16] block,elevator: use new hashtable implementation Date: Tue, 30 Oct 2012 14:46:04 -0400 Message-Id: <1351622772-16400-8-git-send-email-levinsasha928@gmail.com> X-Mailer: git-send-email 1.7.12.4 In-Reply-To: <1351622772-16400-1-git-send-email-levinsasha928@gmail.com> References: <1351622772-16400-1-git-send-email-levinsasha928@gmail.com> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@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 ca51543..a0abbf6 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 9b1d42b..898d0eb 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..7c5a7c9 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 */ @@ -105,8 +108,8 @@ struct elevator_queue void *elevator_data; struct kobject kobj; struct mutex sysfs_lock; - struct hlist_head *hash; unsigned int registered:1; + DECLARE_HASHTABLE(hash, ELV_HASH_BITS); }; /*