From 6a7f6d86a561473032287c8e4583eac5853c6efa Mon Sep 17 00:00:00 2001 From: Dennis Zhou Date: Wed, 5 Dec 2018 12:10:33 -0500 Subject: blkcg: associate a blkg for pages being evicted by swap A prior patch in this series added blkg association to bios issued by cgroups. There are two other paths that we want to attribute work back to the appropriate cgroup: swap and writeback. Here we modify the way swap tags bios to include the blkg. Writeback will be tackle in the next patch. Signed-off-by: Dennis Zhou Reviewed-by: Josef Bacik Acked-by: Tejun Heo Signed-off-by: Jens Axboe --- block/bio.c | 62 +++++++++++++++++++++++++++++++++++++------------------------ 1 file changed, 38 insertions(+), 24 deletions(-) (limited to 'block') diff --git a/block/bio.c b/block/bio.c index 90089124b512..f0f069c1823c 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1957,30 +1957,6 @@ EXPORT_SYMBOL(bioset_init_from_src); #ifdef CONFIG_BLK_CGROUP -#ifdef CONFIG_MEMCG -/** - * bio_associate_blkcg_from_page - associate a bio with the page's blkcg - * @bio: target bio - * @page: the page to lookup the blkcg from - * - * Associate @bio with the blkcg from @page's owning memcg. This works like - * every other associate function wrt references. - */ -int bio_associate_blkcg_from_page(struct bio *bio, struct page *page) -{ - struct cgroup_subsys_state *blkcg_css; - - if (unlikely(bio->bi_css)) - return -EBUSY; - if (!page->mem_cgroup) - return 0; - blkcg_css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, - &io_cgrp_subsys); - bio->bi_css = blkcg_css; - return 0; -} -#endif /* CONFIG_MEMCG */ - /** * bio_associate_blkcg - associate a bio with the specified blkcg * @bio: target bio @@ -2045,6 +2021,44 @@ static void __bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) bio->bi_blkg = blkg_try_get_closest(blkg); } +static void __bio_associate_blkg_from_css(struct bio *bio, + struct cgroup_subsys_state *css) +{ + struct blkcg_gq *blkg; + + rcu_read_lock(); + + blkg = blkg_lookup_create(css_to_blkcg(css), bio->bi_disk->queue); + __bio_associate_blkg(bio, blkg); + + rcu_read_unlock(); +} + +#ifdef CONFIG_MEMCG +/** + * bio_associate_blkg_from_page - associate a bio with the page's blkg + * @bio: target bio + * @page: the page to lookup the blkcg from + * + * Associate @bio with the blkg from @page's owning memcg and the respective + * request_queue. This works like every other associate function wrt + * references. + */ +void bio_associate_blkg_from_page(struct bio *bio, struct page *page) +{ + struct cgroup_subsys_state *css; + + if (unlikely(bio->bi_css)) + return; + if (!page->mem_cgroup) + return; + + css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys); + bio->bi_css = css; + __bio_associate_blkg_from_css(bio, css); +} +#endif /* CONFIG_MEMCG */ + /** * bio_associate_blkg - associate a bio with a blkg * @bio: target bio -- cgit v1.2.3