The patch titled
Subject: proc: fixup PDE allocation bloat
has been added to the -mm tree. Its filename is
proc-fixup-pde-allocation-bloat.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/proc-fixup-pde-allocation-bloat.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/proc-fixup-pde-allocation-bloat.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: 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.
Link: http://lkml.kernel.org/r/20180617215732.GA24688@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/inode.c | 6 ++++--
fs/proc/internal.h | 15 ++++++---------
2 files changed, 10 insertions(+), 11 deletions(-)
diff -puN fs/proc/inode.c~proc-fixup-pde-allocation-bloat fs/proc/inode.c
--- a/fs/proc/inode.c~proc-fixup-pde-allocation-bloat
+++ a/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 -puN fs/proc/internal.h~proc-fixup-pde-allocation-bloat fs/proc/internal.h
--- a/fs/proc/internal.h~proc-fixup-pde-allocation-bloat
+++ a/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)
+#ifdef CONFIG_64BIT
+#define SIZEOF_PDE (sizeof(spinlock_t) <= 4 ? 192 : 256)
+#else
+#define SIZEOF_PDE (sizeof(spinlock_t) <= 4 ? 128 : 192)
+#endif
-#define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE_SLOT - OFFSETOF_PDE_NAME)
+#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);
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
proc-fixup-pde-allocation-bloat.patch
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