From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f193.google.com ([209.85.216.193]:39251 "EHLO mail-qt0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934797AbeFYPMy (ORCPT ); Mon, 25 Jun 2018 11:12:54 -0400 Received: by mail-qt0-f193.google.com with SMTP id c23-v6so3317935qtn.6 for ; Mon, 25 Jun 2018 08:12:53 -0700 (PDT) From: Josef Bacik To: axboe@kernel.dk, linux-block@vger.kernel.org, kernel-team@fb.com, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, tj@kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 05/15] swap,blkcg: issue swap io with the appropriate context Date: Mon, 25 Jun 2018 11:12:33 -0400 Message-Id: <20180625151243.2132-6-josef@toxicpanda.com> In-Reply-To: <20180625151243.2132-1-josef@toxicpanda.com> References: <20180625151243.2132-1-josef@toxicpanda.com> Sender: linux-fsdevel-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 --- 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 57c4b1986e76..c77fe1b4caa8 100644 --- a/block/bio.c +++ b/block/bio.c @@ -2005,6 +2005,30 @@ EXPORT_SYMBOL(bioset_create); #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 f2f3f1428e81..eef1e8877048 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -545,6 +545,13 @@ 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