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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 <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
hifive-unleashed-5.1
Dennis Zhou 2018-12-05 12:10:33 -05:00 committed by Jens Axboe
parent e439bedf6b
commit 6a7f6d86a5
3 changed files with 42 additions and 28 deletions
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62
block/bio.c
View File

@ -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

6
include/linux/bio.h
View File

@ -505,10 +505,10 @@ do { \
disk_devt((bio)->bi_disk)
#if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
int bio_associate_blkcg_from_page(struct bio *bio, struct page *page);
void bio_associate_blkg_from_page(struct bio *bio, struct page *page);
#else
static inline int bio_associate_blkcg_from_page(struct bio *bio,
struct page *page) { return 0; }
static inline void bio_associate_blkg_from_page(struct bio *bio,
struct page *page) { }
#endif
#ifdef CONFIG_BLK_CGROUP

2
mm/page_io.c
View File

@ -339,7 +339,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
goto out;
}
bio->bi_opf = REQ_OP_WRITE | REQ_SWAP | wbc_to_write_flags(wbc);
bio_associate_blkcg_from_page(bio, page);
bio_associate_blkg_from_page(bio, page);
count_swpout_vm_event(page);
set_page_writeback(page);
unlock_page(page);