Eviction changes allowing to evict (remap) cachelines while
holding hash bucket write lock instead of global metadata
write lock.
As eviction (replacement) is now tightly coupled with request,
each request uses eviction size equal to number of its
unmapped cachelines.
Evicting without global metadata write lock is possible
thanks to the fact that remaping is always performed
while exclusively holding cacheline (read or write) lock.
So for a cacheline on LRU list we acquire cacheline lock,
safely resolve hash and consequently write-lock hash bucket.
Since cacheline lock is acquired under hash bucket (everywhere
except for new eviction implementation), we are certain that
noone acquires cacheline lock behind our back. Concurrent
eviction threads are eliminated by holding eviction list
lock for the duration of critial locking operations.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Divide single global lock instance into 4 to reduce contention
in multiple read-locks scenario.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Load properties before checking memory needs and obtain cache line size
from context rather than from cache state.
Signed-off-by: Rafal Stefanowski <rafal.stefanowski@intel.com>
Rather then passing whole structs, supply
_ocf_mngt_calculate_ram_needed() with just the values it actually uses.
Signed-off-by: Rafal Stefanowski <rafal.stefanowski@intel.com>
Fail `ocf_mngt_cache_load` function with `OCF_ERR_INVAL`
error code when force flag is in use.
Log error message.
Closes#361
Signed-off-by: Slawomir Jankowski <slawomir.jankowski@intel.com>
This way debug prints during metadata init phase won't cause crash
(because of the fact that temporary cache object does not have proper
ctx set hence does not have logger obj).
Signed-off-by: Michal Rakowski <michal.rakowski@intel.com>
Change 'OCF_ERR_START_CACHE_FAIL' to 'OCF_ERR_NO_MEM' while CAS fails in case of memory lack on device.
Add new error code for case, when device doesn't satisfy CAS requirements - 'OCF_ERR_INVAL_CACHE_DEV'.
Use 'OCF_ERR_INVAL_CACHE_DEV' in code.
Update error code match in test.
closes#317 issue
Signed-off-by: Ostrokrzew <slawomir.jankowski@intel.com>
To eliminate possibility of allocation error in cache stop, pipeline is
allocated on attach.
Due this change, the only possible non-zero status of ocf_mngt_cache_stop() is
just a warning and cache is always stopped after executing it.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Since we do not expect that incrementing cache's reference counter
during cache init will fail at any condition it is can be changed
to an assert instead of error handling.
Signed-off-by: Michal Rakowski <michal.rakowski@intel.com>
It allows to modify and retrieve particular PP params event if it isn't active
and store values between cache stop and load.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Cache lock waiters hold cache refcount. Because of that,
if there were some waiters, deinitialization of cache
lock on the last put did never happen and putting the
cache was effectively impossible.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
This change allows to check if specified cache name name is unique. To prevent
adding cache instance with the same name, context lock is acquired until name
isn't set.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Adding synchronization around metadata collision segment pages.
This part of metadata is modified when cacheline is mapped/unmapped
and when dirty status changes.
Synchronization on page level is required on top of cacheline
and hash bucket locks to assure metadata flush always reads
consistent state when copying entire collision table memory
page.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
There is one RW lock per hash bucket. Write lock is required
to map cacheline, read lock is sufficient for traversing.
Hash bucket locks are always acquired under global metadata
read lock. This assures mutual exclusion with eviction and
management paths, where global metadata write lock is held.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Global free cacheline list is divided into a set of freelists, one
per execution context. When attempting to map addres to cache, first
the freelist for current execution context is considered (fast path).
If current execution context freelist is empty (fast path failure),
mapping function attempts to get freelist from other execution context
list (slow path).
The purpose of this change is improve concurrency in freelist access.
It is part of fine granularity metadata lock implementation.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Fix problem introduced by increasing partition name size to 1024 bytes,
which effectively made superblock bigger than one page. Due to this
flushing superblock required more than one io, which in case of dirty
shutdown between these ios resulted in CRC missmatch and made cache
recovery impossible.
Moving parts metadata to separate sections makes superblock fitting
in one page, effectively solving described problem.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
Don't try to remove invalid cores
If valid cache metadata was read, but environment has changed (i.e. number of cache lines has changed) ocf (in error handling path) was trying to close cores which were not opened. It happened due to cores were marked in cache metadata as added, but any cache inserting operation didn't take place.
In this patch 'added' flag in cache metadata was replaced with more meaningful 'valid' - it is set if given core is stored in cache metadata. Moreover, new 'added' flag was added to core run-time metadata and it is set if given core is added to cache.
If cleaning policy didn't have init() function,
'_ocf_mngt_init_instance_load_complete' returned early and promotion policy
wasn't initialized at all.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Promotion policy is supposed to perform ALRU noise filtering by
eliminating one-hit wonders being added to cache and polluting it.
Signed-off-by: Jan Musial <jan.musial@intel.com>
When cache is detached we cannot assume there is a management
queue created. This change introduces simplified cache stop
path, performing all the necessary deinit without using
IO queues.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Write-only cache mode is similar to writeback, however read
operations do not promote data to cache. Reads are mostly serviced
by the core device, only dirty sectors are fetched from the cache.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
ocf_request has always been first class citizen in OCF,
so lets place it along with another essential objects.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
ocf_kick_cleaner() allows to perfom cleaning immediately.
Nop cleaning policy now returns new 'OCF_CLEANER_DISABLE' macro which indicates
that cleaing shouldn't be performed. To enable it back, ocf_kick_cleaner()
should be called.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
As non-interruptible flushes are no longer triggered from OCF
internals, we can get rid of "interruption" argument and let
adapters handle it themselves.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
This simplifies code by allowing to express programmer intent
explicitly and helps to avoid missing return statements (this patch
fixes at least one bug related to this).
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
This simplifies cases when we want to call completion callback
and immediately return from void-returning function, by allowing
to explicitly express programmers intent. That way we can avoid
cases when return statement is missing by mistake (this patch
fixes at least one bug related to this).
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
_ocf_mngt_cache_unplug context is now provided by the caller.
This way _ocf_mngt_cache_unplug returns only non-critical (cache write)
errors, allowing stop/detach operation to always proceed and optionally
finish with error. This eliminates the need for rolling back previous
stop/detach operations, which might turn out to be impossible e.g.
under memory pressure.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Errors not related to cache disk I/O failure should force
cache stop to return with error without deinitializing cache
instance.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
This pointer is used to provide optional volume specific data
from the user down to bottom volume open callback. volume_params
is provided to OCF in ocf_mngt_cache_device_config.volume_params.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Cache is used during pipeline_destroy which means that
doing put_cache before destroying pipeline may result in
accessing memory that was freed.
Signed-off-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
This allows to reuse same step functions giving them different parameters
on each step.
Additionally move pipeline to utils, to make it accessible to other
subsystems of OCF (e.g. metadata).
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
NOTE: This is still not the real asynchronism. Metadata interfaces
are still not fully asynchronous.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
NOTE: This patch only changes API that pretends to be asynchronous.
Most of management operations are still performed synchronously.
The real asynchronism will be introduced in the next patches.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
- Queue allocation is now separated from starting cache.
- Queue can be created and destroyed in runtime.
- All queue ops accept queue handle instead of queue id.
- Cache stores queues as list instead of array.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
Instead of switching write policy to pass-through, barrier is rised
by incrementing counter in ocf_cache_t structure.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
