diff options
author | Dave Kleikamp <shaggy@austin.ibm.com> | 2006-03-14 17:05:45 -0600 |
---|---|---|
committer | Dave Kleikamp <shaggy@austin.ibm.com> | 2006-03-14 17:05:45 -0600 |
commit | c5111f504d2a9b0d258d7c4752b4093523315989 (patch) | |
tree | 6a52864aff79691689aea21cb0cb928327d5de5b /block/elevator.c | |
parent | 69eb66d7da7dba2696281981347698e1693c2340 (diff) | |
parent | a488edc914aa1d766a4e2c982b5ae03d5657ec1b (diff) |
Merge with /home/shaggy/git/linus-clean/
Diffstat (limited to 'block/elevator.c')
-rw-r--r-- | block/elevator.c | 114 |
1 files changed, 53 insertions, 61 deletions
diff --git a/block/elevator.c b/block/elevator.c index c9f424d5399..24b702d649a 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -139,35 +139,16 @@ static int elevator_attach(request_queue_t *q, struct elevator_type *e, static char chosen_elevator[16]; -static void elevator_setup_default(void) +static int __init elevator_setup(char *str) { - struct elevator_type *e; - - /* - * If default has not been set, use the compiled-in selection. - */ - if (!chosen_elevator[0]) - strcpy(chosen_elevator, CONFIG_DEFAULT_IOSCHED); - /* * Be backwards-compatible with previous kernels, so users * won't get the wrong elevator. */ - if (!strcmp(chosen_elevator, "as")) + if (!strcmp(str, "as")) strcpy(chosen_elevator, "anticipatory"); - - /* - * If the given scheduler is not available, fall back to the default - */ - if ((e = elevator_find(chosen_elevator))) - elevator_put(e); else - strcpy(chosen_elevator, CONFIG_DEFAULT_IOSCHED); -} - -static int __init elevator_setup(char *str) -{ - strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1); + strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1); return 0; } @@ -184,14 +165,16 @@ int elevator_init(request_queue_t *q, char *name) q->end_sector = 0; q->boundary_rq = NULL; - elevator_setup_default(); + if (name && !(e = elevator_get(name))) + return -EINVAL; - if (!name) - name = chosen_elevator; + if (!e && *chosen_elevator && !(e = elevator_get(chosen_elevator))) + printk("I/O scheduler %s not found\n", chosen_elevator); - e = elevator_get(name); - if (!e) - return -EINVAL; + if (!e && !(e = elevator_get(CONFIG_DEFAULT_IOSCHED))) { + printk("Default I/O scheduler not found, using no-op\n"); + e = elevator_get("noop"); + } eq = kmalloc(sizeof(struct elevator_queue), GFP_KERNEL); if (!eq) { @@ -310,7 +293,7 @@ void elv_requeue_request(request_queue_t *q, struct request *rq) rq->flags &= ~REQ_STARTED; - __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE, 0); + elv_insert(q, rq, ELEVATOR_INSERT_REQUEUE); } static void elv_drain_elevator(request_queue_t *q) @@ -327,40 +310,11 @@ static void elv_drain_elevator(request_queue_t *q) } } -void __elv_add_request(request_queue_t *q, struct request *rq, int where, - int plug) +void elv_insert(request_queue_t *q, struct request *rq, int where) { struct list_head *pos; unsigned ordseq; - if (q->ordcolor) - rq->flags |= REQ_ORDERED_COLOR; - - if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) { - /* - * toggle ordered color - */ - q->ordcolor ^= 1; - - /* - * barriers implicitly indicate back insertion - */ - if (where == ELEVATOR_INSERT_SORT) - where = ELEVATOR_INSERT_BACK; - - /* - * this request is scheduling boundary, update end_sector - */ - if (blk_fs_request(rq)) { - q->end_sector = rq_end_sector(rq); - q->boundary_rq = rq; - } - } else if (!(rq->flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT) - where = ELEVATOR_INSERT_BACK; - - if (plug) - blk_plug_device(q); - rq->q = q; switch (where) { @@ -441,6 +395,42 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where, } } +void __elv_add_request(request_queue_t *q, struct request *rq, int where, + int plug) +{ + if (q->ordcolor) + rq->flags |= REQ_ORDERED_COLOR; + + if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) { + /* + * toggle ordered color + */ + if (blk_barrier_rq(rq)) + q->ordcolor ^= 1; + + /* + * barriers implicitly indicate back insertion + */ + if (where == ELEVATOR_INSERT_SORT) + where = ELEVATOR_INSERT_BACK; + + /* + * this request is scheduling boundary, update + * end_sector + */ + if (blk_fs_request(rq)) { + q->end_sector = rq_end_sector(rq); + q->boundary_rq = rq; + } + } else if (!(rq->flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT) + where = ELEVATOR_INSERT_BACK; + + if (plug) + blk_plug_device(q); + + elv_insert(q, rq, where); +} + void elv_add_request(request_queue_t *q, struct request *rq, int where, int plug) { @@ -669,8 +659,10 @@ int elv_register(struct elevator_type *e) spin_unlock_irq(&elv_list_lock); printk(KERN_INFO "io scheduler %s registered", e->elevator_name); - if (!strcmp(e->elevator_name, chosen_elevator)) - printk(" (default)"); + if (!strcmp(e->elevator_name, chosen_elevator) || + (!*chosen_elevator && + !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED))) + printk(" (default)"); printk("\n"); return 0; } |