+ mm-damon-sysfs-prohibit-multiple-physical-address-space-monitoring-targets.patch added to mm-unstable branch

+ mm-damon-sysfs-prohibit-multiple-physical-address-space-monitoring-targets.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/damon/sysfs: prohibit multiple physical address space monitoring targets
has been added to the -mm mm-unstable branch.  Its filename is
     mm-damon-sysfs-prohibit-multiple-physical-address-space-monitoring-targets.patch

This patch should soon appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: SeongJae Park <sj@kernel.org>
Subject: mm/damon/sysfs: prohibit multiple physical address space monitoring targets

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.

Link: https://lkml.kernel.org/r/20220429160606.127307-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/damon/sysfs.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/mm/damon/sysfs.c~mm-damon-sysfs-prohibit-multiple-physical-address-space-monitoring-targets
+++ a/mm/damon/sysfs.c
@@ -2124,6 +2124,10 @@ static int damon_sysfs_set_targets(struc
 {
 	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];
_

Patches currently in -mm which might be from sj@kernel.org are

mm-damon-core-test-add-a-kunit-test-case-for-ops-registration.patch
mm-damon-core-add-a-function-for-damon_operations-registration-checks.patch
mm-damon-sysfs-add-a-file-for-listing-available-monitoring-ops.patch
selftets-damon-sysfs-test-existence-and-permission-of-avail_operations.patch
docs-abiadmin-guide-damon-document-avail_operations-sysfs-file.patch
mm-damon-vaddr-register-a-damon_operations-for-fixed-virtual-address-ranges-monitoring.patch
mm-damon-sysfs-support-fixed-virtual-address-ranges-monitoring.patch
docs-abiadmin-guide-damon-update-for-fixed-virtual-address-ranges-monitoring.patch
mm-damon-core-add-a-new-callback-for-watermarks-checks.patch
mm-damon-core-finish-kdamond-as-soon-as-any-callback-returns-an-error.patch
mm-damon-vaddr-generalize-damon_va_apply_three_regions.patch
mm-damon-vaddr-move-damon_set_regions-to-core.patch
mm-damon-vaddr-remove-damon_va_apply_three_regions.patch
mm-damon-sysfs-prohibit-multiple-physical-address-space-monitoring-targets.patch
mm-damon-sysfs-move-targets-setup-code-to-a-separated-function.patch
mm-damon-sysfs-reuse-damon_set_regions-for-regions-setting.patch
mm-damon-sysfs-use-enum-for-state-input-handling.patch
mm-damon-sysfs-update-schemes-stat-in-the-kdamond-context.patch
mm-damon-sysfs-support-online-inputs-update.patch
docs-abiadmin-guide-damon-update-for-state-sysfs-file-input-keyword-commit.patch
mm-damon-reclaim-support-online-inputs-update.patch
docs-admin-guide-mm-damon-reclaim-document-commit_inputs-parameter.patch