From: <wli@holomorphy.com>
task_vsize() doesn't need mm->mmap_sem for the CONFIG_MMU case; the
semaphore doesn't prevent mm->total_vm from going stale or getting
inconsistent with other numbers regardless. Also, KSTK_EIP() and
KSTK_ESP() don't want or need protection from mm->mmap_sem either. So this
pushes mm->mmap_sem to task_vsize() in the CONFIG_MMU=n task_vsize().
Also, hoist the prototype of task_vsize() into proc_fs.h
The net result of this is a small speedup of procps for CONFIG_MMU.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/proc/array.c | 3 ---
25-akpm/fs/proc/task_nommu.c | 3 ++-
25-akpm/include/linux/proc_fs.h | 1 +
3 files changed, 3 insertions(+), 4 deletions(-)
diff -puN fs/proc/array.c~task_vsize-locking-cleanup fs/proc/array.c
--- 25/fs/proc/array.c~task_vsize-locking-cleanup 2004-08-23 23:09:42.900281536 -0700
+++ 25-akpm/fs/proc/array.c 2004-08-23 23:09:42.922278192 -0700
@@ -300,7 +300,6 @@ int proc_pid_status(struct task_struct *
return buffer - orig;
}
-extern unsigned long task_vsize(struct mm_struct *);
int proc_pid_stat(struct task_struct *task, char * buffer)
{
unsigned long vsize, eip, esp, wchan;
@@ -320,11 +319,9 @@ int proc_pid_stat(struct task_struct *ta
vsize = eip = esp = 0;
mm = get_task_mm(task);
if (mm) {
- down_read(&mm->mmap_sem);
vsize = task_vsize(mm);
eip = KSTK_EIP(task);
esp = KSTK_ESP(task);
- up_read(&mm->mmap_sem);
}
get_task_comm(tcomm, task);
diff -puN fs/proc/task_nommu.c~task_vsize-locking-cleanup fs/proc/task_nommu.c
--- 25/fs/proc/task_nommu.c~task_vsize-locking-cleanup 2004-08-23 23:09:42.901281384 -0700
+++ 25-akpm/fs/proc/task_nommu.c 2004-08-23 23:09:42.922278192 -0700
@@ -68,11 +68,12 @@ unsigned long task_vsize(struct mm_struc
struct mm_tblock_struct *tbp;
unsigned long vsize = 0;
+ down_read(&mm->mmap_sem);
for (tbp = &mm->context.tblock; tbp; tbp = tbp->next) {
if (tbp->rblock)
vsize += kobjsize(tbp->rblock->kblock);
}
-
+ up_read(&mm->mmap_sem);
return vsize;
}
diff -puN include/linux/proc_fs.h~task_vsize-locking-cleanup include/linux/proc_fs.h
--- 25/include/linux/proc_fs.h~task_vsize-locking-cleanup 2004-08-23 23:09:42.918278800 -0700
+++ 25-akpm/include/linux/proc_fs.h 2004-08-23 23:09:42.923278040 -0700
@@ -90,6 +90,7 @@ struct dentry *proc_pid_lookup(struct in
struct dentry *proc_pid_unhash(struct task_struct *p);
void proc_pid_flush(struct dentry *proc_dentry);
int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir);
+unsigned long task_vsize(struct mm_struct *);
extern struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
struct proc_dir_entry *parent);
_