From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Josef Bacik To: axboe@kernel.dk, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, hannes@cmpxchg.org, tj@kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 05/14] swap,blkcg: issue swap io with the appropriate context Date: Tue, 3 Jul 2018 11:14:54 -0400 Message-Id: <20180703151503.2549-6-josef@toxicpanda.com> In-Reply-To: <20180703151503.2549-1-josef@toxicpanda.com> References: <20180703151503.2549-1-josef@toxicpanda.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: From: Tejun Heo For backcharging we need to know who the page belongs to when swapping it out. We don't worry about things that do ->rw_page (zram etc) at the moment, we're only worried about pages that actually go to a block device. Signed-off-by: Tejun Heo Signed-off-by: Josef Bacik Acked-by: Johannes Weiner cked-by: Andrew Morton --- block/bio.c | 24 ++++++++++++++++++++++++ include/linux/bio.h | 7 +++++++ mm/page_io.c | 1 + 3 files changed, 32 insertions(+) diff --git a/block/bio.c b/block/bio.c index c9072a54395e..e09f3626ab5b 100644 --- a/block/bio.c +++ b/block/bio.c @@ -2015,6 +2015,30 @@ 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 diff --git a/include/linux/bio.h b/include/linux/bio.h index a279ba384da9..a00dfff51aa5 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -553,6 +553,13 @@ do { \ #define bio_dev(bio) \ 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); +#else +static inline int bio_associate_blkcg_from_page(struct bio *bio, + struct page *page) { return 0; } +#endif + #ifdef CONFIG_BLK_CGROUP int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg); diff --git a/mm/page_io.c b/mm/page_io.c index a552cb37e220..aafd19ec1db4 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -339,6 +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); count_swpout_vm_event(page); set_page_writeback(page); unlock_page(page); -- 2.14.3