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| author | SeongJae Park <sj@kernel.org> | 2026-05-22 08:40:20 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-05-28 21:31:24 -0700 |
| commit | 427d242c1e9f50ba1da673903d4c4dab16ae7cd7 (patch) | |
| tree | 4c6f0f6e1c9a9a3388191cbca97fdbf9851586fe /mm | |
| parent | ccc43738c1c7249a9b2a2affe4ca85650f647dbb (diff) | |
| download | linux-next-history-427d242c1e9f50ba1da673903d4c4dab16ae7cd7.tar.gz | |
mm/damon/core: remove damon_verify_nr_regions()
When CONFIG_DAMON_DEBUG_SANITY is enabled, damon_verify_nr_regions() is
called for each damon_nr_regions() invocation. damon_veify_nr_regions()
iterates all regions. damon_nr_regions() is called for each region in
kdamond_reset_aggregated() and damos_apply_scheme(). Hence it imposes
O(n**2) overhead where n is the number of regions.
Though the verification is enabled only under DAMON_DEBUG_SANITY, which is
not for production use cases, it could be too high overhead. Meanwhile,
damon_verify_ctx() is doing the damon_nr_regions() test. Because
damon_verify_ctx() is called for each kdamond_call(), the test coverage
from damon_verify_ctx() could be sufficient. Remove damon_nr_regions()
verification.
Link: https://lore.kernel.org/20260522154026.80546-10-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/damon/core.c | 19 |
1 files changed, 0 insertions, 19 deletions
diff --git a/mm/damon/core.c b/mm/damon/core.c index 00e2997524ece..b33920873871e 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -686,27 +686,8 @@ void damon_destroy_target(struct damon_target *t, struct damon_ctx *ctx) damon_free_target(t); } -#ifdef CONFIG_DAMON_DEBUG_SANITY -static void damon_verify_nr_regions(struct damon_target *t) -{ - struct damon_region *r; - unsigned int count = 0; - - damon_for_each_region(r, t) - count++; - WARN_ONCE(count != t->nr_regions, "t->nr_regions (%u) != count (%u)\n", - t->nr_regions, count); -} -#else -static void damon_verify_nr_regions(struct damon_target *t) -{ -} -#endif - unsigned int damon_nr_regions(struct damon_target *t) { - damon_verify_nr_regions(t); - return t->nr_regions; } |