mm/damon/core: remove unnecessary error messages

DAMON core prints error messages when damon_target object creation is
failed or wrong monitoring attributes are given.  Because appropriate
error code is returned for each case, the messages are not essential.
Also, because the code path can be triggered with user-specified input,
this could result in kernel log mistakenly being messy.  To avoid the
case, this commit removes the messages.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 4bc0595 ("mm/damon: implement a debugfs-based user space interface")
Fixes: b9a6ac4 ("mm/damon: adaptively adjust regions")
Signed-off-by: SeongJae Park <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: kernel test robot <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: sjp38

mm/damon/core.c

@@ -282,7 +282,6 @@ int damon_set_targets(struct damon_ctx *ctx,
 	for (i = 0; i < nr_ids; i++) {
 		t = damon_new_target(ids[i]);
 		if (!t) {
-			pr_err("Failed to alloc damon_target\n");
 			/* The caller should do cleanup of the ids itself */
 			damon_for_each_target_safe(t, next, ctx)
 				damon_destroy_target(t);
@@ -312,16 +311,10 @@ int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
 		    unsigned long aggr_int, unsigned long primitive_upd_int,
 		    unsigned long min_nr_reg, unsigned long max_nr_reg)
 {
-	if (min_nr_reg < 3) {
-		pr_err("min_nr_regions (%lu) must be at least 3\n",
-				min_nr_reg);
+	if (min_nr_reg < 3)
 		return -EINVAL;
-	}
-	if (min_nr_reg > max_nr_reg) {
-		pr_err("invalid nr_regions.  min (%lu) > max (%lu)\n",
-				min_nr_reg, max_nr_reg);
+	if (min_nr_reg > max_nr_reg)
 		return -EINVAL;
-	}
 
 	ctx->sample_interval = sample_int;
 	ctx->aggr_interval = aggr_int;