From: Prasanna Meda <pmeda@akamai.com>
Second version:
Tested it more, and fixed bug in last_addr vs. next_addr handling, and added
comments. Also got rid of assumption that zero adress is not part of address space.
Signed-off-by: Prasanna Meda <pmeda@akamai.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/proc/task_mmu.c | 19 ++++++++++++++-----
1 files changed, 14 insertions(+), 5 deletions(-)
diff -puN fs/proc/task_mmu.c~speedup-proc-pid-maps-fix fs/proc/task_mmu.c
--- 25/fs/proc/task_mmu.c~speedup-proc-pid-maps-fix 2005-02-22 18:17:10.000000000 -0800
+++ 25-akpm/fs/proc/task_mmu.c 2005-02-22 18:17:10.000000000 -0800
@@ -161,6 +161,15 @@ static void *m_start(struct seq_file *m,
tail_map = get_gate_vma(task);
down_read(&mm->mmap_sem);
+ /*
+ * First map is special, since we remember last_addr
+ * rather than current_addr to hit with mmap_cache most of the time.
+ */
+ if (!l) {
+ map = mm->mmap;
+ goto out;
+ }
+
/* Start with last addr hint */
map = find_vma(mm, last_addr);
if (map) {
@@ -168,7 +177,7 @@ static void *m_start(struct seq_file *m,
goto out;
}
- /* Check the map index is within the range */
+ /* Check the map index is within the range, and do linear scan */
if ((unsigned long)l < mm->map_count) {
map = mm->mmap;
while (l-- && map)
@@ -207,16 +216,16 @@ static void *m_next(struct seq_file *m,
{
struct task_struct *task = m->private;
struct vm_area_struct *map = v;
+ struct vm_area_struct *tail_map = get_gate_vma(task);
+
(*pos)++;
if (map && map->vm_next) {
- m->version = map->vm_next->vm_start;
+ m->version = (map != tail_map)? map->vm_start: -1UL;
return map->vm_next;
}
m_stop(m, v);
m->version = -1UL;
- if (map != get_gate_vma(task))
- return get_gate_vma(task);
- return NULL;
+ return (map != tail_map)? tail_map: NULL;
}
struct seq_operations proc_pid_maps_op = {
_