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author | Jens Axboe <jens.axboe@oracle.com> | 2010-02-22 13:48:51 +0100 |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2010-02-22 13:48:51 +0100 |
commit | f11cbd74c5ff3614f6390b4de67a6ffdc614c378 (patch) | |
tree | 6a30920ade9eeaac5bf6d6263b5d09712e882eb0 /block/cfq-iosched.c | |
parent | 429c42c9d246f5bda868495c09974312a0177328 (diff) | |
parent | aea187c46f7d03ce985e55eb1398d0776a15b928 (diff) | |
download | kernel_samsung_tuna-f11cbd74c5ff3614f6390b4de67a6ffdc614c378.zip kernel_samsung_tuna-f11cbd74c5ff3614f6390b4de67a6ffdc614c378.tar.gz kernel_samsung_tuna-f11cbd74c5ff3614f6390b4de67a6ffdc614c378.tar.bz2 |
Merge branch 'master' into for-2.6.34
Diffstat (limited to 'block/cfq-iosched.c')
-rw-r--r-- | block/cfq-iosched.c | 57 |
1 files changed, 23 insertions, 34 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 918c7fd..023f4e6 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -42,16 +42,13 @@ static const int cfq_hist_divisor = 4; */ #define CFQ_MIN_TT (2) -/* - * Allow merged cfqqs to perform this amount of seeky I/O before - * deciding to break the queues up again. - */ -#define CFQQ_COOP_TOUT (HZ) - #define CFQ_SLICE_SCALE (5) #define CFQ_HW_QUEUE_MIN (5) #define CFQ_SERVICE_SHIFT 12 +#define CFQQ_SEEK_THR 8 * 1024 +#define CFQQ_SEEKY(cfqq) ((cfqq)->seek_mean > CFQQ_SEEK_THR) + #define RQ_CIC(rq) \ ((struct cfq_io_context *) (rq)->elevator_private) #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2) @@ -137,7 +134,6 @@ struct cfq_queue { u64 seek_total; sector_t seek_mean; sector_t last_request_pos; - unsigned long seeky_start; pid_t pid; @@ -314,6 +310,7 @@ enum cfqq_state_flags { CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ CFQ_CFQQ_FLAG_sync, /* synchronous queue */ CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ + CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */ CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ }; @@ -342,6 +339,7 @@ CFQ_CFQQ_FNS(prio_changed); CFQ_CFQQ_FNS(slice_new); CFQ_CFQQ_FNS(sync); CFQ_CFQQ_FNS(coop); +CFQ_CFQQ_FNS(split_coop); CFQ_CFQQ_FNS(deep); CFQ_CFQQ_FNS(wait_busy); #undef CFQ_CFQQ_FNS @@ -1566,6 +1564,15 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, cfq_clear_cfqq_wait_busy(cfqq); /* + * If this cfqq is shared between multiple processes, check to + * make sure that those processes are still issuing I/Os within + * the mean seek distance. If not, it may be time to break the + * queues apart again. + */ + if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq)) + cfq_mark_cfqq_split_coop(cfqq); + + /* * store what was left of this slice, if the queue idled/timed out */ if (timed_out && !cfq_cfqq_slice_new(cfqq)) { @@ -1663,9 +1670,6 @@ static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, return cfqd->last_position - blk_rq_pos(rq); } -#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 cfq_queue *cfqq, struct request *rq, bool for_preempt) { @@ -1803,7 +1807,7 @@ static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) * Otherwise, we do only if they are the last ones * in their service tree. */ - return service_tree->count == 1; + return service_tree->count == 1 && cfq_cfqq_sync(cfqq); } static void cfq_arm_slice_timer(struct cfq_data *cfqd) @@ -3000,19 +3004,6 @@ cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, total = cfqq->seek_total + (cfqq->seek_samples/2); do_div(total, cfqq->seek_samples); cfqq->seek_mean = (sector_t)total; - - /* - * If this cfqq is shared between multiple processes, check to - * make sure that those processes are still issuing I/Os within - * the mean seek distance. If not, it may be time to break the - * queues apart again. - */ - if (cfq_cfqq_coop(cfqq)) { - if (CFQQ_SEEKY(cfqq) && !cfqq->seeky_start) - cfqq->seeky_start = jiffies; - else if (!CFQQ_SEEKY(cfqq)) - cfqq->seeky_start = 0; - } } /* @@ -3077,6 +3068,12 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, return true; /* + * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice. + */ + if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq)) + return false; + + /* * if the new request is sync, but the currently running queue is * not, let the sync request have priority. */ @@ -3447,14 +3444,6 @@ cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_context *cic, return cic_to_cfqq(cic, 1); } -static int should_split_cfqq(struct cfq_queue *cfqq) -{ - if (cfqq->seeky_start && - time_after(jiffies, cfqq->seeky_start + CFQQ_COOP_TOUT)) - return 1; - return 0; -} - /* * Returns NULL if a new cfqq should be allocated, or the old cfqq if this * was the last process referring to said cfqq. @@ -3463,9 +3452,9 @@ static struct cfq_queue * split_cfqq(struct cfq_io_context *cic, struct cfq_queue *cfqq) { if (cfqq_process_refs(cfqq) == 1) { - cfqq->seeky_start = 0; cfqq->pid = current->pid; cfq_clear_cfqq_coop(cfqq); + cfq_clear_cfqq_split_coop(cfqq); return cfqq; } @@ -3504,7 +3493,7 @@ new_queue: /* * If the queue was seeky for too long, break it apart. */ - if (cfq_cfqq_coop(cfqq) && should_split_cfqq(cfqq)) { + if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) { cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); cfqq = split_cfqq(cic, cfqq); if (!cfqq) |