From: Jeff Moyer Date: Thu, 29 Sep 2011 09:56:58 +0000 (+0530) Subject: cfq: calculate the seek_mean per cfq_queue not per cfq_io_context X-Git-Tag: v2.6.32.47~28 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4a78a06ce2ecea224c55eb2e171ea020110ecaa9;p=karo-tx-linux.git cfq: calculate the seek_mean per cfq_queue not per cfq_io_context commit b2c18e1e08a5a9663094d57bb4be2f02226ee61c upstream. async cfq_queue's are already shared between processes within the same priority, and forthcoming patches will change the mapping of cic to sync cfq_queue from 1:1 to 1:N. So, calculate the seekiness of a process based on the cfq_queue instead of the cfq_io_context. Signed-off-by: Jeff Moyer Signed-off-by: Jens Axboe Signed-off-by: Suresh Jayaraman Signed-off-by: Greg Kroah-Hartman --- diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 847c9476c20d..3b8847b3ab37 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -112,6 +112,11 @@ struct cfq_queue { unsigned short ioprio, org_ioprio; unsigned short ioprio_class, org_ioprio_class; + unsigned int seek_samples; + u64 seek_total; + sector_t seek_mean; + sector_t last_request_pos; + pid_t pid; }; @@ -967,16 +972,16 @@ static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, return cfqd->last_position - blk_rq_pos(rq); } -#define CIC_SEEK_THR 8 * 1024 -#define CIC_SEEKY(cic) ((cic)->seek_mean > CIC_SEEK_THR) +#define CFQQ_SEEK_THR 8 * 1024 +#define CFQQ_SEEKY(cfqq) ((cfqq)->seek_mean > CFQQ_SEEK_THR) -static inline int cfq_rq_close(struct cfq_data *cfqd, struct request *rq) +static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq, + struct request *rq) { - struct cfq_io_context *cic = cfqd->active_cic; - sector_t sdist = cic->seek_mean; + sector_t sdist = cfqq->seek_mean; - if (!sample_valid(cic->seek_samples)) - sdist = CIC_SEEK_THR; + if (!sample_valid(cfqq->seek_samples)) + sdist = CFQQ_SEEK_THR; return cfq_dist_from_last(cfqd, rq) <= sdist; } @@ -1005,7 +1010,7 @@ static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, * will contain the closest sector. */ __cfqq = rb_entry(parent, struct cfq_queue, p_node); - if (cfq_rq_close(cfqd, __cfqq->next_rq)) + if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) return __cfqq; if (blk_rq_pos(__cfqq->next_rq) < sector) @@ -1016,7 +1021,7 @@ static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, return NULL; __cfqq = rb_entry(node, struct cfq_queue, p_node); - if (cfq_rq_close(cfqd, __cfqq->next_rq)) + if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) return __cfqq; return NULL; @@ -1038,13 +1043,6 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, { struct cfq_queue *cfqq; - /* - * A valid cfq_io_context is necessary to compare requests against - * the seek_mean of the current cfqq. - */ - if (!cfqd->active_cic) - return NULL; - /* * We should notice if some of the queues are cooperating, eg * working closely on the same area of the disk. In that case, @@ -1115,7 +1113,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) * seeks. so allow a little bit of time for him to submit a new rq */ sl = cfqd->cfq_slice_idle; - if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic)) + if (sample_valid(cfqq->seek_samples) && CFQQ_SEEKY(cfqq)) sl = min(sl, msecs_to_jiffies(CFQ_MIN_TT)); mod_timer(&cfqd->idle_slice_timer, jiffies + sl); @@ -1958,33 +1956,33 @@ cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) } static void -cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic, +cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, struct request *rq) { sector_t sdist; u64 total; - if (!cic->last_request_pos) + if (!cfqq->last_request_pos) sdist = 0; - else if (cic->last_request_pos < blk_rq_pos(rq)) - sdist = blk_rq_pos(rq) - cic->last_request_pos; + else if (cfqq->last_request_pos < blk_rq_pos(rq)) + sdist = blk_rq_pos(rq) - cfqq->last_request_pos; else - sdist = cic->last_request_pos - blk_rq_pos(rq); + sdist = cfqq->last_request_pos - blk_rq_pos(rq); /* * Don't allow the seek distance to get too large from the * odd fragment, pagein, etc */ - if (cic->seek_samples <= 60) /* second&third seek */ - sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*1024); + if (cfqq->seek_samples <= 60) /* second&third seek */ + sdist = min(sdist, (cfqq->seek_mean * 4) + 2*1024*1024); else - sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*64); + sdist = min(sdist, (cfqq->seek_mean * 4) + 2*1024*64); - cic->seek_samples = (7*cic->seek_samples + 256) / 8; - cic->seek_total = (7*cic->seek_total + (u64)256*sdist) / 8; - total = cic->seek_total + (cic->seek_samples/2); - do_div(total, cic->seek_samples); - cic->seek_mean = (sector_t)total; + cfqq->seek_samples = (7*cfqq->seek_samples + 256) / 8; + cfqq->seek_total = (7*cfqq->seek_total + (u64)256*sdist) / 8; + total = cfqq->seek_total + (cfqq->seek_samples/2); + do_div(total, cfqq->seek_samples); + cfqq->seek_mean = (sector_t)total; } /* @@ -2006,11 +2004,11 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || - (!cfqd->cfq_latency && cfqd->hw_tag && CIC_SEEKY(cic))) + (!cfqd->cfq_latency && cfqd->hw_tag && CFQQ_SEEKY(cfqq))) enable_idle = 0; else if (sample_valid(cic->ttime_samples)) { unsigned int slice_idle = cfqd->cfq_slice_idle; - if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic)) + if (sample_valid(cfqq->seek_samples) && CFQQ_SEEKY(cfqq)) slice_idle = msecs_to_jiffies(CFQ_MIN_TT); if (cic->ttime_mean > slice_idle) enable_idle = 0; @@ -2077,7 +2075,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, * if this request is as-good as one we would expect from the * current cfqq, let it preempt */ - if (cfq_rq_close(cfqd, rq) && (!cfq_cfqq_coop(new_cfqq) || + if (cfq_rq_close(cfqd, cfqq, rq) && (!cfq_cfqq_coop(new_cfqq) || cfqd->busy_queues == 1)) { /* * Mark new queue coop_preempt, so its coop flag will not be @@ -2127,10 +2125,10 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, cfqq->meta_pending++; cfq_update_io_thinktime(cfqd, cic); - cfq_update_io_seektime(cfqd, cic, rq); + cfq_update_io_seektime(cfqd, cfqq, rq); cfq_update_idle_window(cfqd, cfqq, cic); - cic->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); + cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); if (cfqq == cfqd->active_queue) { /* diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h index 4da4a75c3f1e..eb73632440f1 100644 --- a/include/linux/iocontext.h +++ b/include/linux/iocontext.h @@ -40,16 +40,11 @@ struct cfq_io_context { struct io_context *ioc; unsigned long last_end_request; - sector_t last_request_pos; unsigned long ttime_total; unsigned long ttime_samples; unsigned long ttime_mean; - unsigned int seek_samples; - u64 seek_total; - sector_t seek_mean; - struct list_head queue_list; struct hlist_node cic_list;