[PATCH] perf: remove the extra validity check on nr_pages

[Kaixu Xia]

The function is_power_of_2() also do the check on nr_pages,
so the first check performed is unnecessary. On the other
hand, the key point is to ensure @nr_pages is a power-of-two
number and mostly @nr_pages is a nonzero value, so in the
most cases, the function is_power_of_2() will be called.

Signed-off-by: Kaixu Xia <xiakaixu@xxxxxxxxxx>
---
 kernel/events/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 882f835..abb57c2 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4268,7 +4268,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
 	 * If we have rb pages ensure they're a power-of-two number, so we
 	 * can do bitmasks instead of modulo.
 	 */
-	if (nr_pages != 0 && !is_power_of_2(nr_pages))
+	if (!is_power_of_2(nr_pages))
 		return -EINVAL;
 
 	if (vma_size != PAGE_SIZE * (1 + nr_pages))
-- 
1.8.5.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/