Add header cache to DBObjectMap

OMap is used by PG to store PGLog, so it's called by each write operations.
Because leveldb don't play well in random read and "header_lock" limit the
concurrence. Add a LRU cache to avoid too much overload on seeking header.

Signed-off-by: Haomai Wang <haomaiwang@gmail.com>
osdc/Objecter: flag ops that have been redirected

In the future it may be helpful to know whether an op has been redirected
by the OSD.

We don't need it bad enough now to spend a feature bit to know whether this
flag is reliably set.

Signed-off-by: Sage Weil <sage@inktank.com>
common/Finisher: add queue(list<Context*>&)

Signed-off-by: Samuel Just <sam.just@inktank.com>
ceph-disk: Enable creating multiple osds per dev

This is useful for demos and testing.  Enables
creation of lots of OSDs on a single block device
by simply running ceph-disk prepare more than once,
with a --data-size argument set.

Signed-off-by: John Spray <john.spray@inktank.com>
osd/: move split_list and split_request into OSD

Signed-off-by: Samuel Just <sam.just@inktank.com>
crush: add adjust_subtree_weight()

Adjust the weight for all (leaf) items beneath a subtree.

Signed-off-by: Sage Weil <sage@inktank.com>
mon/OSDMonitor: add 'osd crush reweight-subtree ...'

Reweight all items within a subtree.  For example, you might reweigh tall
OSDs within a rack to a new value.

Signed-off-by: Sage Weil <sage@inktank.com>
mon/OSDMonitor: simplify 'osd crush reweight ...' flow

Use the goto labels; drop the do/while.

Signed-off-by: Sage Weil <sage@inktank.com>
osd_types: add pg_log_t::rollback_info_trimmed_to

Signed-off-by: Samuel Just <sam.just@inktank.com>
common: WRITE_{EQ,CMP}_OPERATORS_1

For when a struct is defined to encapsulate a single value and get
control over implicit conversions that would otherwise be impossible
with typedef.

Signed-off-by: Loic Dachary <loic@dachary.org>
osd: factorize shard_id_t/shard_t into a struct

The struct contains a single uint8_t and is preferred to control
conversions that would otherwise be implicit. There is no difference
between shard_id_t and shard_t. The definition is moved in
include/types.h so it is available to both hobject.h and osd_types.h

http://tracker.ceph.com/issues/8254 Fixes: #8254

Signed-off-by: Loic Dachary <loic@dachary.org>
osd: loop over uint8_t instead of shard_id_t

When looping in the range [0,number of shards[ using a uint8_t variable
which is an integer instead of shard_id_t. The alternative would be
define the ++ operator on shard_id_t but since the two are used
interchangeably in a number of places, that seems unnecessary.

Signed-off-by: Loic Dachary <loic@dachary.org>
osd: explicit shard_id_t() and NO_SHARD

Whenever an integer needs to be converted in a shard_id_t,
replace the implicit conversion with an explicit call to the
constructor.

Replace all ghobject_t::NO_SHARD and ghobject_t::no_shard() with
shard_id_t::NO_SHARD

Signed-off-by: Loic Dachary <loic@dachary.org>
osd: replace shard_t usage with shard_id_t

Signed-off-by: Loic Dachary <loic@dachary.org>
PGLog: initialize complete_to

Signed-off-by: Samuel Just <sam.just@inktank.com>
ceph-common: Implementation of the sharded threadpool.
Threadpool will only be having a single work queue and internally the
work queue will be having multiple storage data structures.
Based on some logic (which is derived class implementation specific)
the work queue will shard the requests among these storage structures.
Each storage will be guarded by finer grained sunchronization
objects. Sharded threadpool threads will be assigned to work on a
shard based on some algorithm which is again derived class implementation
specific.

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
OSD: Sharded Op worker queue implementation for handling OSD ops
This is the implementation for the client of the
sharded thread pool/sharded workQ. Removed the op_wq class and now OSD
ops are going through sharded workqueue model which is used by the
sharded threadpool. Derived ShardedOpWQ implementation has a data structure
called ShardData which has it's own lock/cond and storage. ShardedOpWQ
holds a vector of that and the size of the vector is a config option.
During enqueue operation on the queue, the ops are sharded across these
ShardData based on pg hash % number of shards.
Similarly, in the _process function the sharded thread pool threads are
divided across ShardData based on thread index % number of shards

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
ceph-common: The Sharded threadpool worker logic changed
Now, the _process() of the derived queue is processing one request
at a time and the outer loop is controlled by the sharded threadpool.
The stop/pause/drain functionalities are controlled by the sharded TP.

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
OSD:Derived sharded queue implementation is changed
All the threadpool related stuff like stop/pause/drain etc. are not
handled by sharded queue anymore. All it is implementing are related to
processing,enqueue , signaling of waiting threads and shard queue status.
The pg ordering is been taken care of by introducing a map <pg,op> in each
shard.

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>
WorkQueue: Taking care of potential race condition during pause()
Introduced two variables to keep track of number of threads paused
and drained during threadpool pause/drain. The pause()/drain() call
is waiting till number of pause/drain threads equals to toral number of
thread pool threads.

Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>