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>
.. to make it clean that true means cleaner must lock
cachelines rather than the lock is already being held.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Cacheline concurrency functions have their interface changed
so that the cacheline concurrency private context is
explicitly on the parameter list, rather than being taken
from cache->device->concurrency.cache_line.
Cache pointer is no longer provided as a parameter to these
functions. Cacheline concurrency context now has a pointer
to cache structure (for logging purposes only).
The purpose of this change is to facilitate unit testing.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Removing the logic for oportunistic partition overflow
reduction by evicting more cachelines than actually
required by the request being serviced.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@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>
In case of cleaning metadata used to be flushed only when status of whole cache
line changed to clean.
This patch ensures that metadata flush is triggered after changin status of each
single sector is cache line.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
After second dirty write to cache line which was already dirty, metadata flush
was not triggered. In case of dirty shutdown, this led to data corruption.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
Cleaner doesn't set core object in req as it works in domain of cache
lines, which may belong to various cores. It this case should retrieve
core object not from the req, but from the map instead.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
When single request to cache was issued, stats updating function was called with
0 bytes as value to update. In case of many request issued to cache, stats were
updated only in case of error.
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>
The ocf_async_lock may be used in atomic context, thus we need
to replace synchronization primitives to non-sleeping variants.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
Core is not assigned to request in cleaner, so to increase it's stats it has to
be retrieved from mapping.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>
