This series reworks the filesystem shrinkers. We currently have a set of issues with the current filesystem shrinkers: 1. There is an dependency between dentry and inode cache shrinking that is only implicitly defined by the order of shrinker registration. 2. The shrinkers need to walk the superblock list and pin the superblock to avoid unmount races with the sb going away. 3. The dentry cache uses per-superblock LRUs and proportions reclaim between all the superblocks which means we are doing breadth based reclaim. This means we touch every superblock for every shrinker call, and may only reclaim a single dentry at a time from a given superblock. 4. The inode cache has a global LRU, so it has different reclaim patterns to the dentry cache, despite the fact that the dentry cache is generally the only thing that pins inodes in memory. 5. Filesystems need to register their own shrinkers for caches and can't co-ordinate them with the dentry and inode cache shrinkers. The series starts by converting the inode cache to per-superblock LRUs and changes the shrinker to match the dentry cache (#4). It then adds a context to the shrinker callouts by passing the shrinker structure with the callout. With this, a shrinker structure is added to the superblock structure and a per-superblock shrinker is registered. Both the inode and dentry caches are modified to shrunk via the superblock shrinker, and this directly encodes the dcache/icache dependency inside the shrinker (#1). This shrinker structure also avoids the need to pin the superblock inside the shrinker because the shrinker is unregistered before the superblock is freed (#2). Further, it pushes the proportioning of reclaim between superblocks back up into the shrinker and batches all the reclaim from a superblock into a tight call loop until the shrink cycle for that superblock is complete. This effectively converts reclaim to a depth-based reclaim mechanism which has a smaller CPU cache footprint than the current mechanism (#3). Then a pair of superblock operations that can be used to implement filesystem specific cache reclaim is added. This is split into two operations we don't need to overload the number of objects to scan to indicate that a count should be returned. Finally, the XFS inode cache shrinker is converted to use these superblock operations, removing the need to register a shrinker, keep a global list of XFS filesystems and locking to access the per-filesystem caches. This fixes several new lockdep warnings the XFS shrinker introduces because of the different contexts the shrinker is called in, and allows for correct proportioning of reclaim between the dentry, inode and XFS inode caches on the filesystem to be executed (#5). arch/x86/kvm/mmu.c | 2 +- drivers/gpu/drm/i915/i915_gem.c | 2 +- fs/dcache.c | 137 ++++++--------------------------------- fs/fs-writeback.c | 2 +- fs/gfs2/glock.c | 2 +- fs/gfs2/quota.c | 2 +- fs/gfs2/quota.h | 2 +- fs/inode.c | 64 ++++++------------- fs/mbcache.c | 5 +- fs/nfs/dir.c | 2 +- fs/nfs/internal.h | 3 +- fs/quota/dquot.c | 2 +- fs/super.c | 68 +++++++++++++++++++ fs/ubifs/shrinker.c | 2 +- fs/ubifs/ubifs.h | 2 +- fs/xfs/linux-2.6/xfs_buf.c | 5 +- fs/xfs/linux-2.6/xfs_super.c | 23 +++++-- fs/xfs/linux-2.6/xfs_sync.c | 123 +++++++++------------------------- fs/xfs/linux-2.6/xfs_sync.h | 16 +++-- fs/xfs/quota/xfs_qm.c | 7 ++- fs/xfs/quota/xfs_qm_syscalls.c | 2 +- fs/xfs/xfs_mount.h | 1 - include/linux/fs.h | 22 ++++++ include/linux/mm.h | 2 +- include/linux/writeback.h | 1 - mm/vmscan.c | 8 ++- 26 files changed, 220 insertions(+), 287 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
