Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752964Ab1BNXdS (ORCPT ); Mon, 14 Feb 2011 18:33:18 -0500 Received: from smtp-out.google.com ([74.125.121.67]:54188 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751217Ab1BNXdO convert rfc822-to-8bit (ORCPT ); Mon, 14 Feb 2011 18:33:14 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=VzyVioL/Vq5XqIh4TTn/D+0HWSSJHPC9OLOIwUjKJ3LxBlxQAa74hAmaoOlncOl/D+ OA2+wZfUiJ+RRiNH+eJQ== MIME-Version: 1.0 In-Reply-To: <4D539804.9090308@cn.fujitsu.com> References: <4D51ED26.8050809@cn.fujitsu.com> <4D539804.9090308@cn.fujitsu.com> From: Justin TerAvest Date: Mon, 14 Feb 2011 15:32:49 -0800 Message-ID: Subject: Re: [PATCH 3/6 v4] cfq-iosched: Introduce vdisktime and io weight for CFQ queue To: Gui Jianfeng Cc: Vivek Goyal , Jens Axboe , Shaohua Li , lkml , Chad Talbott , Divyesh Shah Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 17679 Lines: 453 On Wed, Feb 9, 2011 at 11:47 PM, Gui Jianfeng wrote: > Introduce vdisktime and io weight for CFQ queue scheduling. Currently, io priority > maps to a range [100,1000]. It also gets rid of cfq_slice_offset() logic and makes > use the same scheduling algorithm as CFQ group does. This helps for CFQ queue and > group scheduling on the same service tree. Hi Gui, I have a couple of questions inline. Thanks, Justin > > Signed-off-by: Gui Jianfeng > --- > ?block/cfq-iosched.c | ?219 +++++++++++++++++++++++++++++++++++++++------------ > ?1 files changed, 167 insertions(+), 52 deletions(-) > > diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c > index f3a126e..41cef2e 100644 > --- a/block/cfq-iosched.c > +++ b/block/cfq-iosched.c > @@ -39,6 +39,13 @@ static const int cfq_hist_divisor = 4; > ?*/ > ?#define CFQ_IDLE_DELAY ? ? ? ? (HZ / 5) > > +/* > + * The base boosting value. > + */ > +#define CFQ_BOOST_SYNC_BASE ? ? ? ? ?(HZ / 10) > +#define CFQ_BOOST_ASYNC_BASE ? ? ? ? ?(HZ / 25) > + > + > ?/* > ?* below this threshold, we consider thinktime immediate > ?*/ > @@ -99,10 +106,7 @@ struct cfq_entity { > ? ? ? ?struct cfq_rb_root *service_tree; > ? ? ? ?/* service_tree member */ > ? ? ? ?struct rb_node rb_node; > - ? ? ? /* service_tree key, represent the position on the tree */ > - ? ? ? unsigned long rb_key; > - > - ? ? ? /* group service_tree key */ > + ? ? ? /* service_tree key */ > ? ? ? ?u64 vdisktime; > ? ? ? ?bool is_group_entity; > ? ? ? ?unsigned int weight; > @@ -114,6 +118,8 @@ struct cfq_entity { > ?struct cfq_queue { > ? ? ? ?/* The schedule entity */ > ? ? ? ?struct cfq_entity cfqe; > + ? ? ? /* Reposition time */ > + ? ? ? unsigned long reposition_time; Can this be addition time or something else instead? This is set, even when we are not repositioning among service trees. > ? ? ? ?/* reference count */ > ? ? ? ?int ref; > ? ? ? ?/* various state flags, see below */ > @@ -312,6 +318,24 @@ struct cfq_data { > ? ? ? ?struct rcu_head rcu; > ?}; > > +/* > + * Map io priority(7 ~ 0) to io weight(100 ~ 1000) as follows > + * ? ? prio ? ? ? 0 ? ?1 ? ? 2 ? ?3 ? ?4 ? ?5 ? ?6 ? ? 7 > + * ? ? weight ?1000 ?868 ? 740 ?612 ?484 ?356 ?228 ? 100 > + */ > +static inline unsigned int cfq_prio_to_weight(unsigned short ioprio) > +{ > + ? ? ? unsigned int step; > + > + ? ? ? BUG_ON(ioprio >= IOPRIO_BE_NR); > + > + ? ? ? step = (BLKIO_WEIGHT_MAX - BLKIO_WEIGHT_MIN) / (IOPRIO_BE_NR - 1); > + ? ? ? if (ioprio == 0) > + ? ? ? ? ? ? ? return BLKIO_WEIGHT_MAX; > + > + ? ? ? return BLKIO_WEIGHT_MIN + (IOPRIO_BE_NR - ioprio - 1) * step; > +} > + > ?static inline struct cfq_queue * > ?cfqq_of_entity(struct cfq_entity *cfqe) > ?{ > @@ -840,16 +864,6 @@ cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, > ? ? ? ?return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); > ?} > > -static unsigned long cfq_slice_offset(struct cfq_data *cfqd, > - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? struct cfq_queue *cfqq) > -{ > - ? ? ? /* > - ? ? ? ?* just an approximation, should be ok. > - ? ? ? ?*/ > - ? ? ? return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - > - ? ? ? ? ? ? ? ? ? ? ?cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); > -} > - > ?static inline s64 > ?entity_key(struct cfq_rb_root *st, struct cfq_entity *entity) > ?{ > @@ -1199,6 +1213,21 @@ static inline void cfq_put_cfqg(struct cfq_group *cfqg) {} > > ?#endif /* GROUP_IOSCHED */ > > +static inline u64 cfq_get_boost(struct cfq_data *cfqd, > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?struct cfq_queue *cfqq) > +{ > + ? ? ? u64 d; > + > + ? ? ? if (cfq_cfqq_sync(cfqq)) > + ? ? ? ? ? ? ? d = CFQ_BOOST_SYNC_BASE << CFQ_SERVICE_SHIFT; > + ? ? ? else > + ? ? ? ? ? ? ? d = CFQ_BOOST_ASYNC_BASE << CFQ_SERVICE_SHIFT; > + > + ? ? ? d = d * BLKIO_WEIGHT_DEFAULT; > + ? ? ? do_div(d, cfqq->cfqe.weight); > + ? ? ? return d; > +} The logic for cfq_get_boost() looks a lot like cfq_scale_slice(). Instead of duplicating code, can't it just be u64 d; if (cfq_cfqq_sync(cfqq)) return cfq_scale_slice(CFQ_BOOST_SYNC_BASE, cfqq->cfqe); else return cfq_scale_slice(CFQ_BOOST_ASYNC_BASE, cfqq->cfqe); > + > ?/* > ?* The cfqd->service_trees holds all pending cfq_queue's that have > ?* requests waiting to be processed. It is sorted in the order that > @@ -1210,13 +1239,14 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, > ? ? ? ?struct cfq_entity *cfqe; > ? ? ? ?struct rb_node **p, *parent; > ? ? ? ?struct cfq_entity *__cfqe; > - ? ? ? unsigned long rb_key; > - ? ? ? struct cfq_rb_root *service_tree; > + ? ? ? struct cfq_rb_root *service_tree, *orig_st; > ? ? ? ?int left; > ? ? ? ?int new_cfqq = 1; > ? ? ? ?int group_changed = 0; > + ? ? ? s64 key; > > ? ? ? ?cfqe = &cfqq->cfqe; > + ? ? ? orig_st = cfqe->service_tree; > > ?#ifdef CONFIG_CFQ_GROUP_IOSCHED > ? ? ? ?if (!cfqd->cfq_group_isolation > @@ -1224,8 +1254,15 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, > ? ? ? ? ? ?&& cfqq->cfqg && cfqq->cfqg != &cfqd->root_group) { > ? ? ? ? ? ? ? ?/* Move this cfq to root group */ > ? ? ? ? ? ? ? ?cfq_log_cfqq(cfqd, cfqq, "moving to root group"); > - ? ? ? ? ? ? ? if (!RB_EMPTY_NODE(&cfqe->rb_node)) > + ? ? ? ? ? ? ? if (!RB_EMPTY_NODE(&cfqe->rb_node)) { > ? ? ? ? ? ? ? ? ? ? ? ?cfq_group_service_tree_del(cfqd, cfqq->cfqg); > + ? ? ? ? ? ? ? ? ? ? ? /* > + ? ? ? ? ? ? ? ? ? ? ? ?* Group changed, dequeue this CFQ queue from the > + ? ? ? ? ? ? ? ? ? ? ? ?* original service tree. > + ? ? ? ? ? ? ? ? ? ? ? ?*/ > + ? ? ? ? ? ? ? ? ? ? ? cfq_rb_erase(&cfqe->rb_node, cfqe->service_tree); > + ? ? ? ? ? ? ? ? ? ? ? orig_st->total_weight -= cfqe->weight; > + ? ? ? ? ? ? ? } > ? ? ? ? ? ? ? ?cfqq->orig_cfqg = cfqq->cfqg; > ? ? ? ? ? ? ? ?cfqq->cfqg = &cfqd->root_group; > ? ? ? ? ? ? ? ?cfqd->root_group.ref++; > @@ -1234,8 +1271,15 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, > ? ? ? ? ? ? ? ? ? && cfqq_type(cfqq) == SYNC_WORKLOAD && cfqq->orig_cfqg) { > ? ? ? ? ? ? ? ?/* cfqq is sequential now needs to go to its original group */ > ? ? ? ? ? ? ? ?BUG_ON(cfqq->cfqg != &cfqd->root_group); > - ? ? ? ? ? ? ? if (!RB_EMPTY_NODE(&cfqe->rb_node)) > + ? ? ? ? ? ? ? if (!RB_EMPTY_NODE(&cfqe->rb_node)) { > ? ? ? ? ? ? ? ? ? ? ? ?cfq_group_service_tree_del(cfqd, cfqq->cfqg); > + ? ? ? ? ? ? ? ? ? ? ? /* > + ? ? ? ? ? ? ? ? ? ? ? ?* Group changed, dequeue this CFQ queue from the > + ? ? ? ? ? ? ? ? ? ? ? ?* original service tree. > + ? ? ? ? ? ? ? ? ? ? ? ?*/ > + ? ? ? ? ? ? ? ? ? ? ? cfq_rb_erase(&cfqe->rb_node, cfqe->service_tree); > + ? ? ? ? ? ? ? ? ? ? ? orig_st->total_weight -= cfqe->weight; > + ? ? ? ? ? ? ? } > ? ? ? ? ? ? ? ?cfq_put_cfqg(cfqq->cfqg); > ? ? ? ? ? ? ? ?cfqq->cfqg = cfqq->orig_cfqg; > ? ? ? ? ? ? ? ?cfqq->orig_cfqg = NULL; > @@ -1246,47 +1290,68 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, > > ? ? ? ?service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq), > ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?cfqq_type(cfqq)); > + ? ? ? if (RB_EMPTY_NODE(&cfqe->rb_node)) { > + ? ? ? ? ? ? ? /* > + ? ? ? ? ? ? ? ?* If this CFQ queue moves to another group, the original > + ? ? ? ? ? ? ? ?* vdisktime makes no sense any more, reset the vdisktime > + ? ? ? ? ? ? ? ?* here. > + ? ? ? ? ? ? ? ?*/ > + ? ? ? ? ? ? ? parent = rb_last(&service_tree->rb); > + ? ? ? ? ? ? ? if (parent) { > + ? ? ? ? ? ? ? ? ? ? ? u64 pos_offset; > + > + ? ? ? ? ? ? ? ? ? ? ? /* > + ? ? ? ? ? ? ? ? ? ? ? ?* Estimate the position according to its weight and > + ? ? ? ? ? ? ? ? ? ? ? ?* ioprio. > + ? ? ? ? ? ? ? ? ? ? ? ?*/ > + ? ? ? ? ? ? ? ? ? ? ? pos_offset = cfq_get_boost(cfqd, cfqq); > + ? ? ? ? ? ? ? ? ? ? ? /* Debug purpose, should remove. */ > + ? ? ? ? ? ? ? ? ? ? ? cfq_log_cfqq(cfqd, cfqq, "pos_offset: %llu", > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?pos_offset); > + ? ? ? ? ? ? ? ? ? ? ? cfqe->vdisktime = service_tree->min_vdisktime + > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? pos_offset; > + ? ? ? ? ? ? ? } else > + ? ? ? ? ? ? ? ? ? ? ? cfqe->vdisktime = service_tree->min_vdisktime; > + > + ? ? ? ? ? ? ? goto insert; > + ? ? ? } > + > + ? ? ? /* > + ? ? ? ?* Ok, we get here, this CFQ queue is on the service tree, dequeue it > + ? ? ? ?* firstly. > + ? ? ? ?*/ > + ? ? ? cfq_rb_erase(&cfqe->rb_node, cfqe->service_tree); > + ? ? ? orig_st->total_weight -= cfqe->weight; > + > + ? ? ? new_cfqq = 0; > + > ? ? ? ?if (cfq_class_idle(cfqq)) { > - ? ? ? ? ? ? ? rb_key = CFQ_IDLE_DELAY; > ? ? ? ? ? ? ? ?parent = rb_last(&service_tree->rb); > ? ? ? ? ? ? ? ?if (parent && parent != &cfqe->rb_node) { > ? ? ? ? ? ? ? ? ? ? ? ?__cfqe = rb_entry(parent, struct cfq_entity, rb_node); > - ? ? ? ? ? ? ? ? ? ? ? rb_key += __cfqe->rb_key; > + ? ? ? ? ? ? ? ? ? ? ? cfqe->vdisktime = __cfqe->vdisktime + CFQ_IDLE_DELAY; > ? ? ? ? ? ? ? ?} else > - ? ? ? ? ? ? ? ? ? ? ? rb_key += jiffies; > + ? ? ? ? ? ? ? ? ? ? ? cfqe->vdisktime = service_tree->min_vdisktime; > ? ? ? ?} else if (!add_front) { > ? ? ? ? ? ? ? ?/* > - ? ? ? ? ? ? ? ?* Get our rb key offset. Subtract any residual slice > - ? ? ? ? ? ? ? ?* value carried from last service. A negative resid > - ? ? ? ? ? ? ? ?* count indicates slice overrun, and this should position > - ? ? ? ? ? ? ? ?* the next service time further away in the tree. > + ? ? ? ? ? ? ? ?* We charge the CFQ queue by the time this queue runs, and > + ? ? ? ? ? ? ? ?* repsition it on the service tree. > ? ? ? ? ? ? ? ? */ > - ? ? ? ? ? ? ? rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; > - ? ? ? ? ? ? ? rb_key -= cfqq->slice_resid; > + ? ? ? ? ? ? ? unsigned int used_sl; > + > + ? ? ? ? ? ? ? used_sl = cfq_cfqq_slice_usage(cfqq); > + ? ? ? ? ? ? ? cfqe->vdisktime += cfq_scale_slice(used_sl, cfqe); > ? ? ? ? ? ? ? ?cfqq->slice_resid = 0; > ? ? ? ?} else { > - ? ? ? ? ? ? ? rb_key = -HZ; > - ? ? ? ? ? ? ? __cfqe = cfq_rb_first(service_tree); > - ? ? ? ? ? ? ? rb_key += __cfqe ? __cfqe->rb_key : jiffies; > - ? ? ? } > - > - ? ? ? if (!RB_EMPTY_NODE(&cfqe->rb_node)) { > - ? ? ? ? ? ? ? new_cfqq = 0; > - ? ? ? ? ? ? ? /* > - ? ? ? ? ? ? ? ?* same position, nothing more to do > - ? ? ? ? ? ? ? ?*/ > - ? ? ? ? ? ? ? if (rb_key == cfqe->rb_key && > - ? ? ? ? ? ? ? ? ? cfqe->service_tree == service_tree) > - ? ? ? ? ? ? ? ? ? ? ? return; > - > - ? ? ? ? ? ? ? cfq_rb_erase(&cfqe->rb_node, cfqe->service_tree); > - ? ? ? ? ? ? ? cfqe->service_tree = NULL; > + ? ? ? ? ? ? ? cfqe->vdisktime = service_tree->min_vdisktime; > ? ? ? ?} > > +insert: > ? ? ? ?left = 1; > ? ? ? ?parent = NULL; > ? ? ? ?cfqe->service_tree = service_tree; > ? ? ? ?p = &service_tree->rb.rb_node; > + ? ? ? key = entity_key(service_tree, cfqe); > ? ? ? ?while (*p) { > ? ? ? ? ? ? ? ?struct rb_node **n; > > @@ -1296,7 +1361,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, > ? ? ? ? ? ? ? ?/* > ? ? ? ? ? ? ? ? * sort by key, that represents service time. > ? ? ? ? ? ? ? ? */ > - ? ? ? ? ? ? ? if (time_before(rb_key, __cfqe->rb_key)) > + ? ? ? ? ? ? ? if (key < entity_key(service_tree, __cfqe)) > ? ? ? ? ? ? ? ? ? ? ? ?n = &(*p)->rb_left; > ? ? ? ? ? ? ? ?else { > ? ? ? ? ? ? ? ? ? ? ? ?n = &(*p)->rb_right; > @@ -1309,10 +1374,12 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, > ? ? ? ?if (left) > ? ? ? ? ? ? ? ?service_tree->left = &cfqe->rb_node; > > - ? ? ? cfqe->rb_key = rb_key; > ? ? ? ?rb_link_node(&cfqe->rb_node, parent, p); > ? ? ? ?rb_insert_color(&cfqe->rb_node, &service_tree->rb); > + ? ? ? update_min_vdisktime(service_tree); > ? ? ? ?service_tree->count++; > + ? ? ? service_tree->total_weight += cfqe->weight; I'm confused by this line. Why are we doing some adjustment for cfqe weight that we weren't doing previously? I think cfq_group_service_tree_add below will still do the total_weight adjustment. > + ? ? ? cfqq->reposition_time = jiffies; > ? ? ? ?if ((add_front || !new_cfqq) && !group_changed) > ? ? ? ? ? ? ? ?return; > ? ? ? ?cfq_group_service_tree_add(cfqd, cfqq->cfqg); > @@ -1414,14 +1481,18 @@ static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) > ?static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) > ?{ > ? ? ? ?struct cfq_entity *cfqe; > + ? ? ? struct cfq_rb_root *service_tree; > + > ? ? ? ?cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); > ? ? ? ?BUG_ON(!cfq_cfqq_on_rr(cfqq)); > ? ? ? ?cfq_clear_cfqq_on_rr(cfqq); > > ? ? ? ?cfqe = &cfqq->cfqe; > + ? ? ? service_tree = cfqe->service_tree; > > ? ? ? ?if (!RB_EMPTY_NODE(&cfqe->rb_node)) { > ? ? ? ? ? ? ? ?cfq_rb_erase(&cfqe->rb_node, cfqe->service_tree); > + ? ? ? ? ? ? ? service_tree->total_weight -= cfqe->weight; > ? ? ? ? ? ? ? ?cfqe->service_tree = NULL; > ? ? ? ?} > ? ? ? ?if (cfqq->p_root) { > @@ -2120,23 +2191,36 @@ static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) > ? ? ? ?} > ?} > > +/* > + * The time when a CFQ queue is put onto a service tree is recoreded in > + * cfqq->reposition_time. Currently, we check the first priority CFQ queues > + * on each service tree, and select the workload type that contains the lowest > + * reposition_time CFQ queue among them. > + */ > ?static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, > ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?struct cfq_group *cfqg, enum wl_prio_t prio) > ?{ > ? ? ? ?struct cfq_entity *cfqe; > + ? ? ? struct cfq_queue *cfqq; > + ? ? ? unsigned long lowest_start_time; > ? ? ? ?int i; > - ? ? ? bool key_valid = false; > - ? ? ? unsigned long lowest_key = 0; > + ? ? ? bool time_valid = false; > ? ? ? ?enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; > > + ? ? ? /* > + ? ? ? ?* TODO: We may take io priority and io class into account when > + ? ? ? ?* choosing a workload type. But for the time being just make use of > + ? ? ? ?* reposition_time only. > + ? ? ? ?*/ > ? ? ? ?for (i = 0; i <= SYNC_WORKLOAD; ++i) { > - ? ? ? ? ? ? ? /* select the one with lowest rb_key */ > ? ? ? ? ? ? ? ?cfqe = cfq_rb_first(service_tree_for(cfqg, prio, i)); > - ? ? ? ? ? ? ? if (cfqe && > - ? ? ? ? ? ? ? ? ? (!key_valid || time_before(cfqe->rb_key, lowest_key))) { > - ? ? ? ? ? ? ? ? ? ? ? lowest_key = cfqe->rb_key; > + ? ? ? ? ? ? ? cfqq = cfqq_of_entity(cfqe); > + ? ? ? ? ? ? ? if (cfqe && (!time_valid || > + ? ? ? ? ? ? ? ? ? ? ? ? ? ?time_before(cfqq->reposition_time, > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?lowest_start_time))) { > + ? ? ? ? ? ? ? ? ? ? ? lowest_start_time = cfqq->reposition_time; > ? ? ? ? ? ? ? ? ? ? ? ?cur_best = i; > - ? ? ? ? ? ? ? ? ? ? ? key_valid = true; > + ? ? ? ? ? ? ? ? ? ? ? time_valid = true; > ? ? ? ? ? ? ? ?} > ? ? ? ?} > > @@ -2808,10 +2892,13 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc) > ?{ > ? ? ? ?struct task_struct *tsk = current; > ? ? ? ?int ioprio_class; > + ? ? ? struct cfq_entity *cfqe; > > ? ? ? ?if (!cfq_cfqq_prio_changed(cfqq)) > ? ? ? ? ? ? ? ?return; > > + ? ? ? cfqe = &cfqq->cfqe; > + > ? ? ? ?ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); > ? ? ? ?switch (ioprio_class) { > ? ? ? ?default: > @@ -2838,6 +2925,17 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc) > ? ? ? ? ? ? ? ?break; > ? ? ? ?} > > + ? ? ? if (!RB_EMPTY_NODE(&cfqe->rb_node)) { > + ? ? ? ? ? ? ? /* > + ? ? ? ? ? ? ? ?* If this CFQ entity is already on service tree, we need to > + ? ? ? ? ? ? ? ?* adjust service tree's total weight accordingly. > + ? ? ? ? ? ? ? ?*/ > + ? ? ? ? ? ? ? cfqe->service_tree->total_weight -= cfqe->weight; > + ? ? ? ? ? ? ? cfqe->weight = cfq_prio_to_weight(cfqq->ioprio); > + ? ? ? ? ? ? ? cfqe->service_tree->total_weight += cfqe->weight; > + ? ? ? } else > + ? ? ? ? ? ? ? cfqe->weight = cfq_prio_to_weight(cfqq->ioprio); > + > ? ? ? ?/* > ? ? ? ? * keep track of original prio settings in case we have to temporarily > ? ? ? ? * elevate the priority of this queue > @@ -3572,6 +3670,9 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) > ?*/ > ?static void cfq_prio_boost(struct cfq_queue *cfqq) > ?{ > + ? ? ? struct cfq_entity *cfqe; > + > + ? ? ? cfqe = &cfqq->cfqe; > ? ? ? ?if (has_fs_excl()) { > ? ? ? ? ? ? ? ?/* > ? ? ? ? ? ? ? ? * boost idle prio on transactions that would lock out other > @@ -3588,6 +3689,20 @@ static void cfq_prio_boost(struct cfq_queue *cfqq) > ? ? ? ? ? ? ? ?cfqq->ioprio_class = cfqq->org_ioprio_class; > ? ? ? ? ? ? ? ?cfqq->ioprio = cfqq->org_ioprio; > ? ? ? ?} > + > + ? ? ? /* > + ? ? ? ?* update the io weight if io priority gets changed. > + ? ? ? ?*/ > + ? ? ? if (!RB_EMPTY_NODE(&cfqe->rb_node)) { > + ? ? ? ? ? ? ? /* > + ? ? ? ? ? ? ? ?* If this CFQ entity is already on service tree, we need to > + ? ? ? ? ? ? ? ?* adjust service tree's total weight accordingly. > + ? ? ? ? ? ? ? ?*/ > + ? ? ? ? ? ? ? cfqe->service_tree->total_weight -= cfqe->weight; > + ? ? ? ? ? ? ? cfqe->weight = cfq_prio_to_weight(cfqq->ioprio); > + ? ? ? ? ? ? ? cfqe->service_tree->total_weight += cfqe->weight; > + ? ? ? } else > + ? ? ? ? ? ? ? cfqe->weight = cfq_prio_to_weight(cfqq->ioprio); > ?} > > ?static inline int __cfq_may_queue(struct cfq_queue *cfqq) > -- > 1.7.1 > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at ?http://vger.kernel.org/majordomo-info.html > Please read the FAQ at ?http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/