Re: [RFC for-next v2 2/4] bio: split pcpu cache part of bio_put into a helper

From: Christoph Hellwig
Date: Thu Oct 20 2022 - 04:30:38 EST


> + if ((bio->bi_opf & REQ_POLLED) && !WARN_ON_ONCE(in_interrupt())) {
> + bio->bi_next = cache->free_list;
> + cache->free_list = bio;
> + cache->nr++;
> + } else {
> + put_cpu();
> + bio_free(bio);
> + return;
> + }

This reads a little strange with the return in an else. Why not:

if (!(bio->bi_opf & REQ_POLLED) || WARN_ON_ONCE(in_interrupt())) {
put_cpu();
bio_free(bio);
return;
}

bio->bi_next = cache->free_list;
cache->free_list = bio;
cache->nr++;

but given that the simple free case doesn't care about what CPU we're
on or the per-cpu cache pointer, I think we can simply move the

cache = per_cpu_ptr(bio->bi_pool->cache, get_cpu());

after the above return as well.