On Wed, Dec 18, 2024 at 11:56:04AM -0500, Rik van Riel wrote:
[...]
>
> +static bool should_lru_add_drain(void)
> +{
> + struct cpu_fbatches *fbatches = this_cpu_ptr(&cpu_fbatches);
You will need either a local_lock or preempt_disable to access the per
cpu batches.
> + int pending = folio_batch_count(&fbatches->lru_add);
> + pending += folio_batch_count(&fbatches->lru_deactivate);
> + pending += folio_batch_count(&fbatches->lru_deactivate_file);
> + pending += folio_batch_count(&fbatches->lru_lazyfree);
> +
> + /* Don't bother draining unless we have several pages pending. */
> + return pending > SWAP_CLUSTER_MAX;
> +}
> +
> +void maybe_lru_add_drain(void)
Later it might also make sense to see if other users of lru_add_drain()
should be fine with maybe_lru_add_drain() as well.
> +{
> + if (should_lru_add_drain())
> + lru_add_drain();
> +}
> +
