diff options
| -rw-r--r-- | Documentation/block/switching-sched.txt | 22 | ||||
| -rw-r--r-- | block/elevator.c | 2 | ||||
| -rw-r--r-- | block/ll_rw_blk.c | 4 | ||||
| -rw-r--r-- | fs/splice.c | 13 | ||||
| -rw-r--r-- | kernel/fork.c | 1 |
5 files changed, 37 insertions, 5 deletions
diff --git a/Documentation/block/switching-sched.txt b/Documentation/block/switching-sched.txt new file mode 100644 index 000000000000..5fa130a67531 --- /dev/null +++ b/Documentation/block/switching-sched.txt @@ -0,0 +1,22 @@ +As of the Linux 2.6.10 kernel, it is now possible to change the +IO scheduler for a given block device on the fly (thus making it possible, +for instance, to set the CFQ scheduler for the system default, but +set a specific device to use the anticipatory or noop schedulers - which +can improve that device's throughput). + +To set a specific scheduler, simply do this: + +echo SCHEDNAME > /sys/block/DEV/queue/scheduler + +where SCHEDNAME is the name of a defined IO scheduler, and DEV is the +device name (hda, hdb, sga, or whatever you happen to have). + +The list of defined schedulers can be found by simply doing +a "cat /sys/block/DEV/queue/scheduler" - the list of valid names +will be displayed, with the currently selected scheduler in brackets: + +# cat /sys/block/hda/queue/scheduler +noop anticipatory deadline [cfq] +# echo anticipatory > /sys/block/hda/queue/scheduler +# cat /sys/block/hda/queue/scheduler +noop [anticipatory] deadline cfq diff --git a/block/elevator.c b/block/elevator.c index 0d6be03d929e..29825792cbd5 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -895,10 +895,8 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name) EXPORT_SYMBOL(elv_dispatch_sort); EXPORT_SYMBOL(elv_add_request); EXPORT_SYMBOL(__elv_add_request); -EXPORT_SYMBOL(elv_requeue_request); EXPORT_SYMBOL(elv_next_request); EXPORT_SYMBOL(elv_dequeue_request); EXPORT_SYMBOL(elv_queue_empty); -EXPORT_SYMBOL(elv_completed_request); EXPORT_SYMBOL(elevator_exit); EXPORT_SYMBOL(elevator_init); diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index e112d1a5dab6..1755c053fd68 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -1554,7 +1554,7 @@ void blk_plug_device(request_queue_t *q) * don't plug a stopped queue, it must be paired with blk_start_queue() * which will restart the queueing */ - if (test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags)) + if (blk_queue_stopped(q)) return; if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) { @@ -1587,7 +1587,7 @@ EXPORT_SYMBOL(blk_remove_plug); */ void __generic_unplug_device(request_queue_t *q) { - if (unlikely(test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags))) + if (unlikely(blk_queue_stopped(q))) return; if (!blk_remove_plug(q)) diff --git a/fs/splice.c b/fs/splice.c index 22fac87e90b3..0559e7577a04 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -275,6 +275,15 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, error = 0; bytes = 0; for (i = 0; i < nr_pages; i++, index++) { + unsigned int this_len; + + if (!len) + break; + + /* + * this_len is the max we'll use from this page + */ + this_len = min(len, PAGE_CACHE_SIZE - loff); find_page: /* * lookup the page for this index @@ -366,11 +375,13 @@ readpage: * force quit after adding this page */ nr_pages = i; + this_len = min(this_len, loff); } } fill_it: pages[i] = page; - bytes += PAGE_CACHE_SIZE - loff; + bytes += this_len; + len -= this_len; loff = 0; } diff --git a/kernel/fork.c b/kernel/fork.c index 34515772611e..d2fa57d480d4 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -180,6 +180,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) atomic_set(&tsk->usage,2); atomic_set(&tsk->fs_excl, 0); tsk->btrace_seq = 0; + tsk->splice_pipe = NULL; return tsk; } |