I was looking into moving eventfs_inode into a slab, and after cutting and pasting the tracefs allocator: tracefs_inode_cachep = kmem_cache_create("tracefs_inode_cache", sizeof(struct tracefs_inode), 0, (SLAB_RECLAIM_ACCOUNT| SLAB_MEM_SPREAD| SLAB_ACCOUNT), init_once); I figured I should know what those slab flags mean. I also looked at what others in fs use for their slabs. The above is rather common (which I probably just copied from another file system), but I wanted to know what they are for. When I got to SLAB_MEM_SPREAD, I found that it's a common flag and there's a lot of caches that just set that and nothing else. But I couldn't find how it was used. Then I found this commit: 16a1d968358a ("mm/slab: remove mm/slab.c and slab_def.h") Which I think removed the only use case of SLAB_MEM_SPREAD. $ git grep SLAB_MEM_SPREAD mm mm/slab.h: SLAB_MEM_SPREAD | \ That's all I find in the mm directory. Is it obsolete now? Can we delete it? Maybe there's other SLAB_* flags that are no longer used. I don't know, I haven't audited them. -- Steve