Fix mesa_db_compact() segfaulting if compacted DB is empty. This crash
happens on writing cache entry that is bigger than DB's size limit and
when DB is empty, which can be triggered by setting DB size to a small
value.
Fixes: 32211788d0 ("util/disk_cache: Add new mesa-db cache type")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30988>
Use O_CLOEXEC flag for opened cache DB files to not leak cache FDs when
process forks.
Fixes: 32211788d0 ("util/disk_cache: Add new mesa-db cache type")
Suggested-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/11810
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30988>
Taking advantage of the persistent array of index entries. In
particular, it's no longer necessary to read from the index file during
compaction.
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30988>
Instead of allocating separate memory for each index entry in the hash
table, use a single array (backed by a mapping of anonymous memory
pages, which allows efficient array resizes) which holds a copy of the
index file contents.
The hash table now references each entry via its offset in the index
file, so that the array address can change on resize.
This eliminates some index file reads and reduces memory management
overhead for the hash table entries. It should be more efficient in
general.
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30988>
Instead of separate reads per index entry. Should be more efficient.
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30988>
Without this, the hash table needed to be rehashed about
log2(<total number of entries>) times as it grew.
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30988>
The previous behaviour had these issues:
1. It meant that this part of the cache couldn't be used
this time.
2. It left the corrupted index/cache files unchanged, so the same failure
might happen again next time.
Recreating the index & cache files for this part means it can be used,
it just loses any previously cached contents.
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30988>
flock may be interrupted by a signal, in which case it returns with
EINTR error. In this case we need to retry until it returns success
or another error.
Fixes: 32211788d0 ("util/disk_cache: Add new mesa-db cache type")
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30988>
Whenever a single file mesa-db cache hits max size limit, a half of cache
is evicted and the cache file is defragmented. The downside of this eviction
strategy is that it causes high disk IO usage during eviction if mesa-db
cache file size is large.
In order to mitigate this downside, we will split mesa-db into multiple
part such that only one part will be evicted at a time. Each part will be
an individual single file mesa-db cache, like a DB shard. The new multipart
mesa-db cache will merge the parts into a single virtual cache.
This patch introduces two new environment variables:
1. MESA_DISK_CACHE_DATABASE_NUM_PARTS:
Controls number of mesa-db cache file parts. By default 50 parts will be
created. The old pre-multipart mesa-db cache files will be auto-removed
if they exist, i.e. Mesa will switch to the new DB version automatically.
2. MESA_DISK_CACHE_DATABASE_EVICTION_SCORE_2X_PERIOD:
Controls the eviction score doubling time period. The evicted DB part
selection is based on cache entries size weighted by 'last_access_time' of
the entries. By default the cache eviction score is doubled for each month
of cache entry age, i.e. for two equally sized entries where one entry is
older by one month than the other, the older entry will have x2 eviction
score than the other entry. Database part with a highest total eviction
score is selected for eviction.
This patch brings x40 performance improvement of cache eviction time using
multipart cache vs a single file cache due to a smaller eviction portions
and more optimized eviction algorithm.
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20256>
Add support for removal of cache entries to mesa-db cache. This allows
to have a more predictable unit tests by removing dummy entries that
are added to cache when test-cache is created by unit-testing framework.
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20256>
In order to ease writing mesa-db eviction unit tests, stop accounting
mesa-db cache file header size during checking whether cache file reached
the size limit. This change ensures that older unit tests will keep working
whenever cache header version/size will change.
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20256>
Introduce new cache type, the Mesa-DB. This is a single-file read/write
cache that is based on the read-only Fossilize DB cache. Mesa-DB supports
cache size capping. It's a much more efficient cache than the multi-file
cache because Mesa-DB doesn't have the inode overhead. The plan is to make
Mesa-DB the default cache implementation once it will be deemed as stable
and well tested. For now users have to set the new MESA_DISK_CACHE_DATABASE
environment variable in order to active the Mesa-DB cache.
Mesa-DB cache is resilient to corrupted cache files and doesn't require
maintenance from users and developers. The size capping is implemented
by evicting least recently used cache items and compacting the cache
database files with the evicted entries. In order to prevent frequent
compaction of the cache, at minimum a half of cache is evicted when cache
is full.
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16888>
