From patchwork Wed Aug 22 02:27:03 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 1358701 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 C4E8D40210 for ; Wed, 22 Aug 2012 02:31:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753150Ab2HVC1v (ORCPT ); Tue, 21 Aug 2012 22:27:51 -0400 Received: from mail-ob0-f174.google.com ([209.85.214.174]:43131 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754585Ab2HVC1k (ORCPT ); Tue, 21 Aug 2012 22:27:40 -0400 Received: by mail-ob0-f174.google.com with SMTP id uo13so696106obb.19 for ; Tue, 21 Aug 2012 19:27:39 -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=kw6lBz7AA9x/JPu3y/9oTy+sWjWjJfE4AGIuM9ndn+4=; b=DjFBkVFAQGIykUTtIN7NAXHaNbBOLFostYUAxdCaUDkNlDnO7AQzk7jnnEo9PRB1Cw KDMdUdRRsC83js7oxGPqRMUPl0oFOWMVrk7xyOa03MyNioX160bdhEa9ThX5Xpou5qzz yeBZXrWQNaiBpbV46kvIV8aXa/nCOUZmrkOfcqcUbD3pPWQr5Db48DMMZ8d65wnK6OVP fVNzM6OnxjfbGAToPnOX2IWGzH3bs78iiSbriVDuh5kev6azykNoWeDLIMmNNIRBrT21 Mmhoh73fwc18Vv6gGjfzO1gNhmA9JKlku0fvDSxSBoNVqRUsb21HX28AHhZXivkHfKPq 0XVQ== Received: by 10.182.117.71 with SMTP id kc7mr14377718obb.62.1345602459810; Tue, 21 Aug 2012 19:27:39 -0700 (PDT) Received: from lappy.us.oracle.com (95-89-78-76-dynip.superkabel.de. [95.89.78.76]) by mx.google.com with ESMTPS id c6sm2813551obn.13.2012.08.21.19.27.33 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 21 Aug 2012 19:27:38 -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 v3 08/17] block,elevator: use new hashtable implementation Date: Wed, 22 Aug 2012 04:27:03 +0200 Message-Id: <1345602432-27673-9-git-send-email-levinsasha928@gmail.com> X-Mailer: git-send-email 1.7.8.6 In-Reply-To: <1345602432-27673-1-git-send-email-levinsasha928@gmail.com> References: <1345602432-27673-1-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 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; };