mm/damon/core: finish kdamond as soon as any callback returns an error

When 'after_sampling()' or 'after_aggregation()' DAMON callbacks return an
error, kdamond continues the remaining loop once.  It makes no much sense
to run the remaining part while something wrong already happened.  The
context might be corrupted or having invalid data.  This commit therefore
makes kdamond skips the remaining works and immediately finish in the
cases.

Link: https://lkml.kernel.org/r/20220429160606.127307-3-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/core.c b/mm/damon/core.c
index 44fe7e4..b6daaff 100644 (file)
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -1089,8 +1089,10 @@ static int kdamond_fn(void *data)
                if (ctx->ops.prepare_access_checks)
                        ctx->ops.prepare_access_checks(ctx);
                if (ctx->callback.after_sampling &&
-                               ctx->callback.after_sampling(ctx))
+                               ctx->callback.after_sampling(ctx)) {
                        done = true;
+                       continue;
+               }
 
                kdamond_usleep(ctx->sample_interval);
 
@@ -1102,8 +1104,10 @@ static int kdamond_fn(void *data)
                                        max_nr_accesses / 10,
                                        sz_limit);
                        if (ctx->callback.after_aggregation &&
-                                       ctx->callback.after_aggregation(ctx))
+                                       ctx->callback.after_aggregation(ctx)) {
                                done = true;
+                               continue;
+                       }
                        kdamond_apply_schemes(ctx);
                        kdamond_reset_aggregated(ctx);
                        kdamond_split_regions(ctx);