reduce m_start() cost...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2014-02-27 14:40:10 -05:00
parent f2ebb3a921
commit c7999c3627
3 changed files with 23 additions and 4 deletions

View File

@@ -52,7 +52,7 @@ static int __init set_mphash_entries(char *str)
}
__setup("mphash_entries=", set_mphash_entries);
static int event;
static u64 event;
static DEFINE_IDA(mnt_id_ida);
static DEFINE_IDA(mnt_group_ida);
static DEFINE_SPINLOCK(mnt_id_lock);
@@ -1100,14 +1100,29 @@ static void *m_start(struct seq_file *m, loff_t *pos)
struct proc_mounts *p = proc_mounts(m);
down_read(&namespace_sem);
return seq_list_start(&p->ns->list, *pos);
if (p->cached_event == p->ns->event) {
void *v = p->cached_mount;
if (*pos == p->cached_index)
return v;
if (*pos == p->cached_index + 1) {
v = seq_list_next(v, &p->ns->list, &p->cached_index);
return p->cached_mount = v;
}
}
p->cached_event = p->ns->event;
p->cached_mount = seq_list_start(&p->ns->list, *pos);
p->cached_index = *pos;
return p->cached_mount;
}
static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{
struct proc_mounts *p = proc_mounts(m);
return seq_list_next(v, &p->ns->list, pos);
p->cached_mount = seq_list_next(v, &p->ns->list, pos);
p->cached_index = *pos;
return p->cached_mount;
}
static void m_stop(struct seq_file *m, void *v)