The patch titled
Subject: mm/damon/sysfs: use enum for 'state' input handling
has been added to the -mm mm-unstable branch. Its filename is
mm-damon-sysfs-use-enum-for-state-input-handling.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@xxxxxxxxxx>
Subject: mm/damon/sysfs: use enum for 'state' input handling
DAMON sysfs 'state' file handling code is using string literals in both
'state_show()' and 'state_store()'. This makes the code error prone and
inflexible for future extensions.
To improve the situation, this commit defines possible input strings and
'enum' for identifying each input keyword only once, and refactors the
code to reuse those.
Link: https://lkml.kernel.org/r/20220429160606.127307-10-sj@xxxxxxxxxx
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/damon/sysfs.c | 72 ++++++++++++++++++++++++++++++++++++++-------
1 file changed, 62 insertions(+), 10 deletions(-)
--- a/mm/damon/sysfs.c~mm-damon-sysfs-use-enum-for-state-input-handling
+++ a/mm/damon/sysfs.c
@@ -2053,6 +2053,32 @@ static bool damon_sysfs_ctx_running(stru
return running;
}
+/*
+ * enum damon_sysfs_cmd - Commands for a specific kdamond.
+ */
+enum damon_sysfs_cmd {
+ /* @DAMON_SYSFS_CMD_ON: Turn the kdamond on. */
+ DAMON_SYSFS_CMD_ON,
+ /* @DAMON_SYSFS_CMD_OFF: Turn the kdamond off. */
+ DAMON_SYSFS_CMD_OFF,
+ /*
+ * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS: Update scheme stats sysfs
+ * files.
+ */
+ DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS,
+ /*
+ * @NR_DAMON_SYSFS_CMDS: Total number of DAMON sysfs commands.
+ */
+ NR_DAMON_SYSFS_CMDS,
+};
+
+/* Should match with enum damon_sysfs_cmd */
+static const char * const damon_sysfs_cmd_strs[] = {
+ "on",
+ "off",
+ "update_schemes_stats",
+};
+
static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
@@ -2066,7 +2092,9 @@ static ssize_t state_show(struct kobject
else
running = damon_sysfs_ctx_running(ctx);
- return sysfs_emit(buf, "%s\n", running ? "on" : "off");
+ return sysfs_emit(buf, "%s\n", running ?
+ damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_ON] :
+ damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_OFF]);
}
static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
@@ -2324,23 +2352,47 @@ static int damon_sysfs_update_schemes_st
return 0;
}
+/*
+ * damon_sysfs_handle_cmd() - Handle a command for a specific kdamond.
+ * @cmd: The command to handle.
+ * @kdamond: The kobject wrapper for the associated kdamond.
+ *
+ * This function handles a DAMON sysfs command for a kdamond.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int damon_sysfs_handle_cmd(enum damon_sysfs_cmd cmd,
+ struct damon_sysfs_kdamond *kdamond)
+{
+ switch (cmd) {
+ case DAMON_SYSFS_CMD_ON:
+ return damon_sysfs_turn_damon_on(kdamond);
+ case DAMON_SYSFS_CMD_OFF:
+ return damon_sysfs_turn_damon_off(kdamond);
+ case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:
+ return damon_sysfs_update_schemes_stats(kdamond);
+ default:
+ break;
+ }
+ return -EINVAL;
+}
+
static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t count)
{
struct damon_sysfs_kdamond *kdamond = container_of(kobj,
struct damon_sysfs_kdamond, kobj);
- ssize_t ret;
+ enum damon_sysfs_cmd cmd;
+ ssize_t ret = -EINVAL;
if (!mutex_trylock(&damon_sysfs_lock))
return -EBUSY;
- if (sysfs_streq(buf, "on"))
- ret = damon_sysfs_turn_damon_on(kdamond);
- else if (sysfs_streq(buf, "off"))
- ret = damon_sysfs_turn_damon_off(kdamond);
- else if (sysfs_streq(buf, "update_schemes_stats"))
- ret = damon_sysfs_update_schemes_stats(kdamond);
- else
- ret = -EINVAL;
+ for (cmd = 0; cmd < NR_DAMON_SYSFS_CMDS; cmd++) {
+ if (sysfs_streq(buf, damon_sysfs_cmd_strs[cmd])) {
+ ret = damon_sysfs_handle_cmd(cmd, kdamond);
+ break;
+ }
+ }
mutex_unlock(&damon_sysfs_lock);
if (!ret)
ret = count;
_
Patches currently in -mm which might be from sj@xxxxxxxxxx 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
