sched/debug: Use match_string() helper instead of open-coded logic

match_string() returns the index of an array for a matching string,
which can be used instead of the open coded variant.

Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/1527765086-19873-15-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index e593b41..c96e89c 100644 (file)
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -111,20 +111,19 @@ static int sched_feat_set(char *cmp)
                cmp += 3;
        }
 
-       for (i = 0; i < __SCHED_FEAT_NR; i++) {
-               if (strcmp(cmp, sched_feat_names[i]) == 0) {
-                       if (neg) {
-                               sysctl_sched_features &= ~(1UL << i);
-                               sched_feat_disable(i);
-                       } else {
-                               sysctl_sched_features |= (1UL << i);
-                               sched_feat_enable(i);
-                       }
-                       break;
-               }
+       i = match_string(sched_feat_names, __SCHED_FEAT_NR, cmp);
+       if (i < 0)
+               return i;
+
+       if (neg) {
+               sysctl_sched_features &= ~(1UL << i);
+               sched_feat_disable(i);
+       } else {
+               sysctl_sched_features |= (1UL << i);
+               sched_feat_enable(i);
        }
 
-       return i;
+       return 0;
 }
 
 static ssize_t
@@ -133,7 +132,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
 {
        char buf[64];
        char *cmp;
-       int i;
+       int ret;
        struct inode *inode;
 
        if (cnt > 63)
@@ -148,10 +147,10 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
        /* Ensure the static_key remains in a consistent state */
        inode = file_inode(filp);
        inode_lock(inode);
-       i = sched_feat_set(cmp);
+       ret = sched_feat_set(cmp);
        inode_unlock(inode);
-       if (i == __SCHED_FEAT_NR)
-               return -EINVAL;
+       if (ret < 0)
+               return ret;
 
        *ppos += cnt;