From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-331097-1516221607-2-11255185338314768303 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES unknown, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-usb-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1516221607; b=r41f3czAMXhkP80wTU+TUN8/629tcePka7d1NBCx6v1WsES 5yZf59594EcAsGSo9jqRAhzuCIZBCQbUVlWvbXuk4hKl7NiesU6decjL+Fwse6/I r3PzPMBrZ5o6M8U4uSRKQfxvysCBeZKU944R4LvtCipKiSrgrOvWaKSV88siJrd3 dC5ascMDP4iYVgR0uqiUYKG72exCWNLLHCA3sWDEpOnyax3dIjpJ/l4mkPUM+MHK JcRvFgyKvHMNeHmwmDv3mx6SmwcGbCrZrYeiozvGHiYWcu1+E20Scqe2yvEgGvCA 0LxKe6YFoAj54oSrt4m0V3Co4BojfKtzhcDg18Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:sender:list-id; s=arctest; t=1516221607; bh=HkDy3jx7uIIOP4XwK0WcyVtDCPydANLwzactgZNjCXI=; b=W0amFGvx6eom O3i2IenQqO70WbE7Gf+C0N6HuL2Eqrz0DNBfbuV/2Kfuu1+26mqK0A4kusaSlaPI fe6QK7l7wUkILxT2trk+8NIHaBUK8Y/Z3C1Xip+wdGSU4nSP04CyBVDDwPaktHti yCuEE8thvafrO5rGpmsvSPmJ1Bv3q/0ocvKf7NrINBVArVPJEDld2D9aTkvfTirR CR/ZoaJcQ8HEtaGnjPW87s4aLIm68RH4R5rBXsyrsiw6kqt4lkomwvNJ52zfDRnx 3eroB6EWvDvqu3Mt7GB2U6wWNktH2IH0gbUpofgn4fnWN5pz5yEx61aoejqjCCsF jv0Hp8V4Kg== ARC-Authentication-Results: i=1; mx4.messagingengine.com; arc=none (no signatures found); dkim=fail (message has been altered; 2048-bit rsa key sha256) header.d=infradead.org header.i=@infradead.org header.b=ZJH5TeDI x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=bombadil.20170209; dmarc=none (p=none,has-list-id=yes,d=none) header.from=infradead.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-usb-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=infradead.org header.result=pass header_is_org_domain=yes Authentication-Results: mx4.messagingengine.com; arc=none (no signatures found); dkim=fail (message has been altered; 2048-bit rsa key sha256) header.d=infradead.org header.i=@infradead.org header.b=ZJH5TeDI x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=bombadil.20170209; dmarc=none (p=none,has-list-id=yes,d=none) header.from=infradead.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-usb-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=infradead.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754652AbeAQUjb (ORCPT ); Wed, 17 Jan 2018 15:39:31 -0500 Received: from bombadil.infradead.org ([65.50.211.133]:38269 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753793AbeAQUWy (ORCPT ); Wed, 17 Jan 2018 15:22:54 -0500 From: Matthew Wilcox To: linux-kernel@vger.kernel.org Cc: Matthew Wilcox , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org, Bjorn Andersson , Stefano Stabellini , iommu@lists.linux-foundation.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, intel-gfx@lists.freedesktop.org, cgroups@vger.kernel.org, linux-sh@vger.kernel.org, David Howells Subject: [PATCH v6 67/99] mm: Convert cgroup writeback to XArray Date: Wed, 17 Jan 2018 12:21:31 -0800 Message-Id: <20180117202203.19756-68-willy@infradead.org> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180117202203.19756-1-willy@infradead.org> References: <20180117202203.19756-1-willy@infradead.org> Sender: linux-usb-owner@vger.kernel.org X-Mailing-List: linux-usb@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: Matthew Wilcox This is a fairly naive conversion, leaving in place the GFP_ATOMIC allocation. By switching the locking around, we could use GFP_KERNEL and probably simplify the error handling. Signed-off-by: Matthew Wilcox --- include/linux/backing-dev-defs.h | 2 +- include/linux/backing-dev.h | 2 +- mm/backing-dev.c | 22 ++++++++++------------ 3 files changed, 12 insertions(+), 14 deletions(-) diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index bfe86b54f6c1..074a54aad33c 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -187,7 +187,7 @@ struct backing_dev_info { struct bdi_writeback wb; /* the root writeback info for this bdi */ struct list_head wb_list; /* list of all wbs */ #ifdef CONFIG_CGROUP_WRITEBACK - struct radix_tree_root cgwb_tree; /* radix tree of active cgroup wbs */ + struct xarray cgwb_xa; /* radix tree of active cgroup wbs */ struct rb_root cgwb_congested_tree; /* their congested states */ #else struct bdi_writeback_congested *wb_congested; diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 3df0d20e23f3..27e7b31bd802 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -271,7 +271,7 @@ static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi if (!memcg_css->parent) return &bdi->wb; - wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); + wb = xa_load(&bdi->cgwb_xa, memcg_css->id); /* * %current's blkcg equals the effective blkcg of its memcg. No diff --git a/mm/backing-dev.c b/mm/backing-dev.c index b5f940ce0143..aa0f85df0928 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -417,8 +417,8 @@ static void wb_exit(struct bdi_writeback *wb) #include /* - * cgwb_lock protects bdi->cgwb_tree, bdi->cgwb_congested_tree, - * blkcg->cgwb_list, and memcg->cgwb_list. bdi->cgwb_tree is also RCU + * cgwb_lock protects bdi->cgwb_xa, bdi->cgwb_congested_tree, + * blkcg->cgwb_list, and memcg->cgwb_list. bdi->cgwb_xa is also RCU * protected. */ static DEFINE_SPINLOCK(cgwb_lock); @@ -539,7 +539,7 @@ static void cgwb_kill(struct bdi_writeback *wb) { lockdep_assert_held(&cgwb_lock); - WARN_ON(!radix_tree_delete(&wb->bdi->cgwb_tree, wb->memcg_css->id)); + WARN_ON(xa_erase(&wb->bdi->cgwb_xa, wb->memcg_css->id) != wb); list_del(&wb->memcg_node); list_del(&wb->blkcg_node); percpu_ref_kill(&wb->refcnt); @@ -571,7 +571,7 @@ static int cgwb_create(struct backing_dev_info *bdi, /* look up again under lock and discard on blkcg mismatch */ spin_lock_irqsave(&cgwb_lock, flags); - wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); + wb = xa_load(&bdi->cgwb_xa, memcg_css->id); if (wb && wb->blkcg_css != blkcg_css) { cgwb_kill(wb); wb = NULL; @@ -614,8 +614,7 @@ static int cgwb_create(struct backing_dev_info *bdi, spin_lock_irqsave(&cgwb_lock, flags); if (test_bit(WB_registered, &bdi->wb.state) && blkcg_cgwb_list->next && memcg_cgwb_list->next) { - /* we might have raced another instance of this function */ - ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb); + ret = xa_insert(&bdi->cgwb_xa, memcg_css->id, wb, GFP_ATOMIC); if (!ret) { list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list); list_add(&wb->memcg_node, memcg_cgwb_list); @@ -682,7 +681,7 @@ struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi, do { rcu_read_lock(); - wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); + wb = xa_load(&bdi->cgwb_xa, memcg_css->id); if (wb) { struct cgroup_subsys_state *blkcg_css; @@ -704,7 +703,7 @@ static int cgwb_bdi_init(struct backing_dev_info *bdi) { int ret; - INIT_RADIX_TREE(&bdi->cgwb_tree, GFP_ATOMIC); + xa_init(&bdi->cgwb_xa); bdi->cgwb_congested_tree = RB_ROOT; ret = wb_init(&bdi->wb, bdi, 1, GFP_KERNEL); @@ -717,15 +716,14 @@ static int cgwb_bdi_init(struct backing_dev_info *bdi) static void cgwb_bdi_unregister(struct backing_dev_info *bdi) { - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &bdi->cgwb_xa, 0); struct bdi_writeback *wb; WARN_ON(test_bit(WB_registered, &bdi->wb.state)); spin_lock_irq(&cgwb_lock); - radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0) - cgwb_kill(*slot); + xas_for_each(&xas, wb, ULONG_MAX) + cgwb_kill(wb); while (!list_empty(&bdi->wb_list)) { wb = list_first_entry(&bdi->wb_list, struct bdi_writeback, -- 2.15.1