On shrinkable caches
Hello,
I have a question regarding the SLAB_RECLAIM_ACCOUNT flag with which BTRFS caches are created. Currently there isn't a single usage of register_shrinker under fs/btrfs. Apart from the inode cache which is being shrunk from the generic super_cache_scan I don't think the memory used for those caches should be accounted as reclaimable?
Regards,
Nikolay
Quoted 3 lines · Nikolay Borisov
I have a question regarding the
SLAB_RECLAIM_ACCOUNTflag with which BTRFS caches are created. Currently there isn't a single usage ofregister_shrinkerunder fs/btrfs.
The SLAB_RECLAIM_ACCOUNT flag has been there since the first versions in 2007 (when shrinkeres did not exist) but I can't find any specific reason why.
Quoted 3 lines
Apart from the inode cache which is
being shrunk from the genericsuper_cache_scanI don't think the memory used for those caches should be accounted as reclaimable?
I agree, in most cases I don't see any possibility to reclaim the objects earlier than the explicit free.
Quoted 9 lines · David Sterba
Quoted 3 lines · Nikolay Borisov
I have a question regarding the
SLAB_RECLAIM_ACCOUNTflag with which BTRFS caches are created. Currently there isn't a single usage ofregister_shrinkerunder fs/btrfs.The
SLAB_RECLAIM_ACCOUNTflag has been there since the first versions in 2007 (when shrinkeres did not exist) but I can't find any specific reason why.
Quoted 6 lines
Quoted 3 lines
Apart from the inode cache which is
being shrunk from the genericsuper_cache_scanI don't think the memory used for those caches should be accounted as reclaimable?I agree, in most cases I don't see any possibility to reclaim the objects earlier than the explicit free.
If that's the case, then I'll be happy to send a patch.