From b4884f23331ae31e9ecb617956986c3b76ab9a91 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Tue, 10 Apr 2018 16:31:52 -0700 Subject: proc: move "struct proc_dir_entry" into kmem cache "struct proc_dir_entry" is variable sized because of 0-length trailing array for name, however, because of SLAB padding allocations it is possible to make "struct proc_dir_entry" fixed sized and allocate same amount of memory. It buys fine-grained debugging with poisoning and usercopy protection which is not possible with kmalloc-* caches. Currently, on 32-bit 91+ byte allocations go into kmalloc-128 and on 64-bit 147+ byte allocations go to kmalloc-192 anyway. Additional memory is allocated only for 38/46+ byte long names which are rare or may not even exist in the wild. Link: http://lkml.kernel.org/r/20180223205504.GA17139@avx2 Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/inode.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/proc/inode.c') diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 89618836887d..2cf3b74391ca 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -104,6 +104,10 @@ void __init proc_init_kmemcache(void) pde_opener_cache = kmem_cache_create("pde_opener", sizeof(struct pde_opener), 0, SLAB_ACCOUNT|SLAB_PANIC, NULL); + proc_dir_entry_cache = kmem_cache_create_usercopy( + "proc_dir_entry", sizeof(struct proc_dir_entry), 0, SLAB_PANIC, + offsetof(struct proc_dir_entry, inline_name), + sizeof_field(struct proc_dir_entry, inline_name), NULL); } static int proc_show_options(struct seq_file *seq, struct dentry *root) -- cgit v1.2.3