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authorDennis Zhou (Facebook) <dennisszhou@gmail.com>2018-09-11 14:41:31 -0400
committerJens Axboe <axboe@kernel.dk>2018-09-21 20:29:09 -0600
commit74b7c02a9bc124ee3df0d77880ee26db0a325516 (patch)
tree9600af0dbec0293940a7e0fdfea7e2b1f7dba7e3 /block
parent5bf9a1f3b4efef7e463105dde8bba4d2397909c2 (diff)
downloadlinux-74b7c02a9bc124ee3df0d77880ee26db0a325516.tar.bz2
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 <dennisszhou@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/bio.c83
1 files changed, 59 insertions, 24 deletions
diff --git a/block/bio.c b/block/bio.c
index 80c948da061c..387480de6992 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1956,30 +1956,6 @@ 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
@@ -2030,6 +2006,65 @@ int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg)
return 0;
}
+static int __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);
+
+ rcu_read_unlock();
+
+ return bio_associate_blkg(bio, blkg);
+}
+
+/**
+ * bio_associate_blkg_from_css - associate a bio with a specified css
+ * @bio: target bio
+ * @css: target css
+ *
+ * Associate @bio with the blkg found by combining the css's blkg and the
+ * request_queue of the @bio. This takes a reference on the css that will
+ * be put upon freeing of @bio.
+ */
+int bio_associate_blkg_from_css(struct bio *bio,
+ struct cgroup_subsys_state *css)
+{
+ css_get(css);
+ bio->bi_css = css;
+ return __bio_associate_blkg_from_css(bio, css);
+}
+EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);
+
+#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.
+ *
+ * Note: this must be called after bio has an associated device.
+ */
+int bio_associate_blkg_from_page(struct bio *bio, struct page *page)
+{
+ struct cgroup_subsys_state *css;
+
+ if (unlikely(bio->bi_css))
+ return -EBUSY;
+ if (!page->mem_cgroup)
+ return 0;
+ css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys);
+ bio->bi_css = css;
+
+ return __bio_associate_blkg_from_css(bio, css);
+}
+#endif /* CONFIG_MEMCG */
+
/**
* bio_associate_create_blkg - associate a bio with a blkg from q
* @q: request_queue where bio is going