From 2d6e4e822ad8174b59414903ae6b35660032c20a Mon Sep 17 00:00:00 2001
From: Alexey Dobriyan <adobriyan@gmail.com>
Date: Tue, 21 Aug 2018 21:54:09 -0700
Subject: [PATCH] proc: fixup PDE allocation bloat
24074a35c5c975 ("proc: Make inline name size calculation automatic")
started to put PDE allocations into kmalloc-256 which is unnecessary as
~40 character names are very rare.
Put allocation back into kmalloc-192 cache for 64-bit non-debug builds.
Put BUILD_BUG_ON to know when PDE size has gotten out of control.
[adobriyan@gmail.com: fix BUILD_BUG_ON breakage on powerpc64]
Link: http://lkml.kernel.org/r/20180703191602.GA25521@avx2
Link: http://lkml.kernel.org/r/20180617215732.GA24688@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/proc/inode.c | 6 ++++--
fs/proc/internal.h | 17 +++++++----------
2 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 85ffbd27f2883..fc5306a31a1d8 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -105,8 +105,10 @@ void __init proc_init_kmemcache(void)
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_PDE_SLOT, 0, SLAB_PANIC,
- OFFSETOF_PDE_NAME, SIZEOF_PDE_INLINE_NAME, NULL);
+ "proc_dir_entry", SIZEOF_PDE, 0, SLAB_PANIC,
+ offsetof(struct proc_dir_entry, inline_name),
+ SIZEOF_PDE_INLINE_NAME, NULL);
+ BUILD_BUG_ON(sizeof(struct proc_dir_entry) >= SIZEOF_PDE);
}
static int proc_show_options(struct seq_file *seq, struct dentry *root)
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index f5b75d258d226..c9d97818a4216 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -65,16 +65,13 @@ struct proc_dir_entry {
char inline_name[];
} __randomize_layout;
-#define OFFSETOF_PDE_NAME offsetof(struct proc_dir_entry, inline_name)
-#define SIZEOF_PDE_SLOT \
- (OFFSETOF_PDE_NAME + 34 <= 64 ? 64 : \
- OFFSETOF_PDE_NAME + 34 <= 128 ? 128 : \
- OFFSETOF_PDE_NAME + 34 <= 192 ? 192 : \
- OFFSETOF_PDE_NAME + 34 <= 256 ? 256 : \
- OFFSETOF_PDE_NAME + 34 <= 512 ? 512 : \
- 0)
-
-#define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE_SLOT - OFFSETOF_PDE_NAME)
+#define SIZEOF_PDE ( \
+ sizeof(struct proc_dir_entry) < 128 ? 128 : \
+ sizeof(struct proc_dir_entry) < 192 ? 192 : \
+ sizeof(struct proc_dir_entry) < 256 ? 256 : \
+ sizeof(struct proc_dir_entry) < 512 ? 512 : \
+ 0)
+#define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE - sizeof(struct proc_dir_entry))
extern struct kmem_cache *proc_dir_entry_cache;
void pde_free(struct proc_dir_entry *pde);
--
GitLab