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authorAlexey Dobriyan <adobriyan@gmail.com>2018-02-06 15:37:18 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-06 18:32:43 -0800
commit163cf548db888710695d5dbe907cda4262d45b52 (patch)
tree14cea8648f3c812770a5b2c9fba35ef634ef0e0e /fs/proc
parentd0290bc20d4739b7a900ae37eb5d4cc3be2b393f (diff)
downloadlinux-163cf548db888710695d5dbe907cda4262d45b52.tar.bz2
fs/proc/internal.h: rearrange struct proc_dir_entry
struct proc_dir_entry became bit messy over years: * move 16-bit ->mode_t before namelen to get rid of padding * make ->in_use first field: it seems to be most used resulting in smaller code on x86_64 (defconfig): add/remove: 0/0 grow/shrink: 7/13 up/down: 24/-67 (-43) Function old new delta proc_readdir_de 451 455 +4 proc_get_inode 282 286 +4 pde_put 65 69 +4 remove_proc_subtree 294 297 +3 remove_proc_entry 297 300 +3 proc_register 295 298 +3 proc_notify_change 94 97 +3 unuse_pde 27 26 -1 proc_reg_write 89 85 -4 proc_reg_unlocked_ioctl 85 81 -4 proc_reg_read 89 85 -4 proc_reg_llseek 87 83 -4 proc_reg_get_unmapped_area 123 119 -4 proc_entry_rundown 139 135 -4 proc_reg_poll 91 85 -6 proc_reg_mmap 79 73 -6 proc_get_link 55 49 -6 proc_reg_release 108 101 -7 proc_reg_open 298 291 -7 close_pdeo 228 218 -10 * move writeable fields together to a first cacheline (on x86_64), those include * ->in_use: reference count, taken every open/read/write/close etc * ->count: reference count, taken at readdir on every entry * ->pde_openers: tracks (nearly) every open, dirtied * ->pde_unload_lock: spinlock protecting ->pde_openers * ->proc_iops, ->proc_fops, ->data: writeonce fields, used right together with previous group. * other rarely written fields go into 1st/2nd and 2nd/3rd cacheline on 32-bit and 64-bit respectively. Additionally on 32-bit, ->subdir, ->subdir_node, ->namelen, ->name go fully into 2nd cacheline, separated from writeable fields. They are all used during lookup. Link: http://lkml.kernel.org/r/20171220215914.GA7877@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/internal.h23
1 files changed, 13 insertions, 10 deletions
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 4a67188c8d74..a290a1e921a5 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -31,24 +31,27 @@ struct mempolicy;
* subdir_node is used to build the rb tree "subdir" of the parent.
*/
struct proc_dir_entry {
+ /*
+ * number of callers into module in progress;
+ * negative -> it's going away RSN
+ */
+ atomic_t in_use;
+ atomic_t count; /* use count */
+ struct list_head pde_openers; /* who did ->open, but not ->release */
+ spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
+ struct completion *pde_unload_completion;
+ const struct inode_operations *proc_iops;
+ const struct file_operations *proc_fops;
+ void *data;
unsigned int low_ino;
- umode_t mode;
nlink_t nlink;
kuid_t uid;
kgid_t gid;
loff_t size;
- const struct inode_operations *proc_iops;
- const struct file_operations *proc_fops;
struct proc_dir_entry *parent;
struct rb_root_cached subdir;
struct rb_node subdir_node;
- void *data;
- atomic_t count; /* use count */
- atomic_t in_use; /* number of callers into module in progress; */
- /* negative -> it's going away RSN */
- struct completion *pde_unload_completion;
- struct list_head pde_openers; /* who did ->open, but not ->release */
- spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
+ umode_t mode;
u8 namelen;
char name[];
} __randomize_layout;