Hi, Another iteration of the SMO patch set, updates to this version are restricted to the dcache patch #14. Applies on top of Linus' tree (tag: v5.1-rc6). This is a patch set implementing movable objects within the SLUB allocator. This is work based on Christopher Lameter's patch set: https://lore.kernel.org/patchwork/project/lkml/list/?series=377335 The original code logic is from that set and implemented by Christopher. Clean up, refactoring, documentation, and additional features by myself. Responsibility for any bugs remaining falls solely with myself. Changes to this version: Re-write the dcache Slab Movable Objects isolate/migrate functions. Based on review/suggestions by Alexander on the last version. In this version the isolate function loops over the object vector and builds a shrink list for all objects that have refcount==0 AND are NOT on anyone else's shrink list. A pointer to this list is returned from the isolate function and passed to the migrate function (by the SMO infrastructure). The dentry migration function d_partial_shrink() simply calls shrink_dentry_list() on the received shrink list pointer and frees the memory associated with the list_head. Hopefully if this is all ok I can move on to violating the inode slab cache :) FWIW testing on a VM in Qemu brings this mild benefit to the dentry slab cache with no _apparent_ negatives. CONFIG_SLUB_DEBUG=y CONFIG_SLUB=y CONFIG_SLUB_CPU_PARTIAL=y CONFIG_SLUB_DEBUG_ON=y CONFIG_SLUB_STATS=y CONFIG_SMO_NODE=y CONFIG_DCACHE_SMO=y [root@vm ~]# slabinfo dentry -r | head -n 13 Slabcache: dentry Aliases: 0 Order : 1 Objects: 38585 ** Reclaim accounting active ** Defragmentation at 30% Sizes (bytes) Slabs Debug Memory ------------------------------------------------------------------------ Object : 192 Total : 2582 Sanity Checks : On Total: 21151744 SlabObj: 528 Full : 2547 Redzoning : On Used : 7408320 SlabSiz: 8192 Partial: 35 Poisoning : On Loss : 13743424 Loss : 336 CpuSlab: 0 Tracking : On Lalig: 12964560 Align : 8 Objects: 15 Tracing : Off Lpadd: 702304 [root@vm ~]# slabinfo dentry --shrink [root@vm ~]# slabinfo dentry -r | head -n 13 Slabcache: dentry Aliases: 0 Order : 1 Objects: 38426 ** Reclaim accounting active ** Defragmentation at 30% Sizes (bytes) Slabs Debug Memory ------------------------------------------------------------------------ Object : 192 Total : 2578 Sanity Checks : On Total: 21118976 SlabObj: 528 Full : 2547 Redzoning : On Used : 7377792 SlabSiz: 8192 Partial: 31 Poisoning : On Loss : 13741184 Loss : 336 CpuSlab: 0 Tracking : On Lalig: 12911136 Align : 8 Objects: 15 Tracing : Off Lpadd: 701216 Please note, this dentry shrink implementation is 'best effort', results vary. This is as is expected. We are trying to unobtrusively shrink the dentry cache. thanks, Tobin. Tobin C. Harding (15): slub: Add isolate() and migrate() methods tools/vm/slabinfo: Add support for -C and -M options slub: Sort slab cache list slub: Slab defrag core tools/vm/slabinfo: Add remote node defrag ratio output tools/vm/slabinfo: Add defrag_used_ratio output tools/testing/slab: Add object migration test module tools/testing/slab: Add object migration test suite xarray: Implement migration function for objects tools/testing/slab: Add XArray movable objects tests slub: Enable moving objects to/from specific nodes slub: Enable balancing slabs across nodes dcache: Provide a dentry constructor dcache: Implement partial shrink via Slab Movable Objects dcache: Add CONFIG_DCACHE_SMO Documentation/ABI/testing/sysfs-kernel-slab | 14 + fs/dcache.c | 110 ++- include/linux/slab.h | 71 ++ include/linux/slub_def.h | 10 + lib/radix-tree.c | 13 + lib/xarray.c | 49 ++ mm/Kconfig | 14 + mm/slab_common.c | 2 +- mm/slub.c | 819 ++++++++++++++++++-- tools/testing/slab/Makefile | 10 + tools/testing/slab/slub_defrag.c | 567 ++++++++++++++ tools/testing/slab/slub_defrag.py | 451 +++++++++++ tools/testing/slab/slub_defrag_xarray.c | 211 +++++ tools/vm/slabinfo.c | 51 +- 14 files changed, 2299 insertions(+), 93 deletions(-) create mode 100644 tools/testing/slab/Makefile create mode 100644 tools/testing/slab/slub_defrag.c create mode 100755 tools/testing/slab/slub_defrag.py create mode 100644 tools/testing/slab/slub_defrag_xarray.c -- 2.21.0
