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| author | Alexey Dobriyan <adobriyan@gmail.com> | 2018-04-11 01:31:52 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-11 19:28:34 +0200 |
| commit | b4884f23331ae31e9ecb617956986c3b76ab9a91 (patch) | |
| tree | 2f25f7337f1aedbfed4fa18b1b26ffa208136544 /fs/proc/inode.c | |
| parent | proc: test /proc/self/syscall (diff) | |
| download | linux-b4884f23331ae31e9ecb617956986c3b76ab9a91.tar.xz linux-b4884f23331ae31e9ecb617956986c3b76ab9a91.zip | |
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 <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/inode.c')
| -rw-r--r-- | fs/proc/inode.c | 4 |
1 files changed, 4 insertions, 0 deletions
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) |