linux-stable.git/drivers/md/bcache/alloc.c, branch linux-3.14.y

bcache: Improve bucket_prio() calculation

2014-01-08T21:05:14+00:00

When deciding what order to reuse buckets we take into account both the bucket's
priority (which indicates lru order) and also the amount of live data in that
bucket. The way they were scaled together wasn't as correct as it could be...
this patch improves and documents it.

Signed-off-by: Kent Overstreet

bcache: Rework allocator reserves

2014-01-08T21:05:09+00:00

We need a reserve for allocating buckets for new btree nodes - and now that
we've got multiple btrees, it really needs to be per btree.

This reworks the reserves so we've got separate freelists for each reserve
instead of watermarks, which seems to make things a bit cleaner, and it adds
some code so that btree_split() can make sure the reserve is available before it
starts.

Signed-off-by: Kent Overstreet

bcache: bugfix - moving_gc now moves only correct buckets

2013-12-16T22:22:58+00:00

Removed gc_move_threshold because picking buckets only by
threshold could lead moving extra buckets (ei. if there are
buckets at the threshold that aren't supposed to be moved
do to space considerations).

This is replaced by a GC_MOVE bit in the gc_mark bitmask.
Now only marked buckets get moved.

Signed-off-by: Nicholas Swenson 
Signed-off-by: Kent Overstreet

bcache: Don't bother with bucket refcount for btree node allocations

2013-11-11T05:56:34+00:00

The bucket refcount (dropped with bkey_put()) is only needed to prevent
the newly allocated bucket from being garbage collected until we've
added a pointer to it somewhere. But for btree node allocations, the
fact that we have btree nodes locked is enough to guard against races
with garbage collection.

Eventually the per bucket refcount is going to be replaced with
something specific to bch_alloc_sectors().

Signed-off-by: Kent Overstreet

bcache: Debug code improvements

2013-11-11T05:56:34+00:00

Couple changes:
 * Consolidate bch_check_keys() and bch_check_key_order(), and move the
   checks that only check_key_order() could do to bch_btree_iter_next().

 * Get rid of CONFIG_BCACHE_EDEBUG - now, all that code is compiled in
   when CONFIG_BCACHE_DEBUG is enabled, and there's now a sysfs file to
   flip on the EDEBUG checks at runtime.

 * Dropped an old not terribly useful check in rw_unlock(), and
   refactored/improved a some of the other debug code.

Signed-off-by: Kent Overstreet

bcache: Move sector allocator to alloc.c

2013-11-11T05:56:32+00:00

Just reorganizing things a bit.

Signed-off-by: Kent Overstreet

bcache: Convert gc to a kthread

2013-11-11T05:56:04+00:00

We needed a dedicated rescuer workqueue for gc anyways... and gc was
conceptually a dedicated thread, just one that wasn't running all the
time. Switch it to a dedicated thread to make the code a bit more
straightforward.

Signed-off-by: Kent Overstreet

bcache: Convert bucket_wait to wait_queue_head_t

2013-11-11T05:56:04+00:00

At one point we did do fancy asynchronous waiting stuff with
bucket_wait, but that's all gone (and bucket_wait is used a lot less
than it used to be). So use the standard primitives.

Signed-off-by: Kent Overstreet

bcache: Use blkdev_issue_discard()

2013-11-11T05:55:54+00:00

The old asynchronous discard code was really a relic from when all the
allocation code was asynchronous - now that allocation runs out of a
dedicated thread there's no point in keeping around all that complicated
machinery.

Signed-off-by: Kent Overstreet

bcache: Allocation kthread fixes

2013-07-12T07:22:49+00:00

The alloc kthread should've been using try_to_freeze() - and also there
was the potential for the alloc kthread to get woken up after it had
shut down, which would have been bad.

Signed-off-by: Kent Overstreet