2022-04-29 18:34:04

by SeongJae Park

[permalink] [raw]
Subject: [PATCH 06/14] mm/damon/sysfs: prohibit multiple physical address space monitoring targets

From: SeongJae Park <[email protected]>

Having multiple targets for physical address space monitoring makes no
sense. This commit prohibits such a ridiculous DAMON context setup my
making the DAMON context build function to check and return an error for
the case.

Signed-off-by: SeongJae Park <[email protected]>
---
mm/damon/sysfs.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 767ab8c33e4d..988247d35862 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -2124,6 +2124,10 @@ static int damon_sysfs_set_targets(struct damon_ctx *ctx,
{
int i, err;

+ /* Multiple physical address space monitoring targets makes no sense */
+ if (ctx->ops.id == DAMON_OPS_PADDR && sysfs_targets->nr > 1)
+ return -EINVAL;
+
for (i = 0; i < sysfs_targets->nr; i++) {
struct damon_sysfs_target *sys_target =
sysfs_targets->targets_arr[i];
--
2.25.1