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>
1. new abbreviated previx: ocf_hb (HB stands for hash bucket)
2. clear distinction between functions requiring caller to
hold metadata shared global lock ("naked") vs the ones
which acquire global lock on its own ("prot" for protected)
3. clear distinction between hash bucket locking functions
accepting hash bucket id ("id"), core line and lba ("cline")
and entire request ("req").
Resulting naming scheme:
ocf_hb_(id/cline/req)_(prot/naked)_(lock/unlock/trylock)_(rd/wr)
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
If there is any dirty data on the cache associated with removed core,
we must flush collision metadata after removing core to make metadata
persistent in case of dirty shutdown.
This fixes the problem when recovery procedure erroneously interprets
cache lines that belonged to removed core as valid ones.
This also fixes the problem, when after removing core containing dirty
data another core is added, and then recovery procedure following dirty
shutdown assigns cache lines from removed core to the new one, effectively
leading to data corruption.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
Min and max values, keept as an explicit number of cachelines, are tightly
coupled with particular cache. This might lead to errors and mismatches after
reattaching cache of different size.
To prevent those errors, min and max should be calculated dynamically.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@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>
There is no need to constantly hold metadata global lock
during collecting cachelines to clean. Since we are past
freezing dirty request counter, we know for sure that the
number of dirty cache lines will not increase. So the worst
case is when the loop realxes and releases the lock,
a concurent IO to CAS is serviced in WT mode, possibly
inserting and/or evicting cachelines. This does not interfere
with scanning for dirty cachelines. And the lower layer will
handle synchronization with concurrent I/O by acquiring
asynchronous read lock on each cleaned cacheline.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
In current implementation in case of fast media flushning
container may starve all concurrent containers flushing
due to continous rescheduling of offender requests to the
front of I/O queue. Pushing request to the back of IO
queue ensures FIFO handling and removes possibility of
starvation.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Lower layer is prepared to handle used cachelines by
acquiring asynchronus read lock. It is very likely that
by the time the cacheline is actually cleaned its lock
state changes. So checking the lock at the moment of
constructing dirty cachelines list makes little sense.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Moving _ocf_mngt_flush_containers outside global metadata
critical section. All this function does is sort core lines
and add queue request.
This fixes stalls reported by Linux scheduler due to
IO threads waiting on global metadata RW semaprhore for
several minutes.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@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>
