For each round-trip, we assign generation on first invocation and compare
it on subsequent invocations.
Let's move them together to make it more self-explaining. Also this
reduce a check on prev.
[hannes@cmpxchg.org: better comment to explain reclaim model]
Link: https://lkml.kernel.org/r/20220330234719.18340-4-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mz = root->nodeinfo[reclaim->pgdat->node_id];
iter = &mz->iter;
- if (prev && reclaim->generation != iter->generation)
+ /*
+ * On start, join the current reclaim iteration cycle.
+ * Exit when a concurrent walker completes it.
+ */
+ if (!prev)
+ reclaim->generation = iter->generation;
+ else if (reclaim->generation != iter->generation)
goto out_unlock;
while (1) {
if (!memcg)
iter->generation++;
- else if (!prev)
- reclaim->generation = iter->generation;
}
out_unlock: