mm/damon/lru_sort: use damon_commit_ctx()

DAMON_LRU_SORT manually manipulates the DAMON context struct for online
parameters update.  Since the struct contains not only input parameters
but also internal status and operation results, it is not that simple.
Indeed, we found and fixed a few bugs in the code.  Now DAMON core layer
provides a function for the usage, namely damon_commit_ctx().  Replace the
manual manipulation logic with the function.  The core layer function
could have its own bugs, but this change removes a source of bugs.

Link: https://lkml.kernel.org/r/20240618181809.82078-12-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 3775f0f2743d5c85420277e751991e313d0fe49f..f83542973946e8ec78c11a6bc10d7d8d3047c2e0 100644 (file)
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -199,15 +199,22 @@ static void damon_lru_sort_copy_quota_status(struct damos_quota *dst,
 
 static int damon_lru_sort_apply_parameters(void)
 {
+       struct damon_ctx *param_ctx;
+       struct damon_target *param_target;
        struct damos *scheme, *hot_scheme, *cold_scheme;
        struct damos *old_hot_scheme = NULL, *old_cold_scheme = NULL;
        unsigned int hot_thres, cold_thres;
-       int err = 0;
+       int err;
 
-       err = damon_set_attrs(ctx, &damon_lru_sort_mon_attrs);
+       err = damon_modules_new_paddr_ctx_target(&param_ctx, &param_target);
        if (err)
                return err;
 
+       err = damon_set_attrs(ctx, &damon_lru_sort_mon_attrs);
+       if (err)
+               goto out;
+
+       err = -ENOMEM;
        damon_for_each_scheme(scheme, ctx) {
                if (!old_hot_scheme) {
                        old_hot_scheme = scheme;
@@ -220,7 +227,7 @@ static int damon_lru_sort_apply_parameters(void)
                hot_thres_access_freq / 1000;
        hot_scheme = damon_lru_sort_new_hot_scheme(hot_thres);
        if (!hot_scheme)
-               return -ENOMEM;
+               goto out;
        if (old_hot_scheme)
                damon_lru_sort_copy_quota_status(&hot_scheme->quota,
                                &old_hot_scheme->quota);
@@ -229,18 +236,24 @@ static int damon_lru_sort_apply_parameters(void)
        cold_scheme = damon_lru_sort_new_cold_scheme(cold_thres);
        if (!cold_scheme) {
                damon_destroy_scheme(hot_scheme);
-               return -ENOMEM;
+               goto out;
        }
        if (old_cold_scheme)
                damon_lru_sort_copy_quota_status(&cold_scheme->quota,
                                &old_cold_scheme->quota);
 
-       damon_set_schemes(ctx, &hot_scheme, 1);
-       damon_add_scheme(ctx, cold_scheme);
+       damon_set_schemes(param_ctx, &hot_scheme, 1);
+       damon_add_scheme(param_ctx, cold_scheme);
 
-       return damon_set_region_biggest_system_ram_default(target,
+       err = damon_set_region_biggest_system_ram_default(param_target,
                                        &monitor_region_start,
                                        &monitor_region_end);
+       if (err)
+               goto out;
+       err = damon_commit_ctx(ctx, param_ctx);
+out:
+       damon_destroy_ctx(param_ctx);
+       return err;
 }
 
 static int damon_lru_sort_turn(bool on)