From: Matthew Wilcox <willy@infradead.org>
To: unlisted-recipients:; (no To-header on input)
Cc: Matthew Wilcox <mawilcox@microsoft.com>,
Ross Zwisler <ross.zwisler@linux.intel.com>,
Jens Axboe <axboe@kernel.dk>, Rehas Sachdeva <aquannie@gmail.com>,
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,
linux-kernel@vger.kernel.org
Subject: [PATCH v4 34/73] mm: Convert cgroup writeback to XArray
Date: Tue, 5 Dec 2017 16:41:20 -0800 [thread overview]
Message-ID: <20171206004159.3755-35-willy@infradead.org> (raw)
In-Reply-To: <20171206004159.3755-1-willy@infradead.org>
From: Matthew Wilcox <mawilcox@microsoft.com>
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 <mawilcox@microsoft.com>
---
include/linux/backing-dev-defs.h | 2 +-
include/linux/backing-dev.h | 2 +-
mm/backing-dev.c | 28 ++++++++++++++++------------
3 files changed, 18 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 9038f6c1eeda..50f666d23527 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 84b2dc76f140..7aa2d893f929 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -417,8 +417,8 @@ static void wb_exit(struct bdi_writeback *wb)
#include <linux/memcontrol.h>
/*
- * 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;
@@ -615,13 +615,18 @@ static int cgwb_create(struct backing_dev_info *bdi,
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);
- if (!ret) {
+ void *curr = xa_cmpxchg(&bdi->cgwb_xa, memcg_css->id, NULL,
+ wb, GFP_ATOMIC);
+ if (!curr) {
list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list);
list_add(&wb->memcg_node, memcg_cgwb_list);
list_add(&wb->blkcg_node, blkcg_cgwb_list);
css_get(memcg_css);
css_get(blkcg_css);
+ } else if (IS_ERR(curr)) {
+ ret = PTR_ERR(curr);
+ } else {
+ ret = -EEXIST;
}
}
spin_unlock_irqrestore(&cgwb_lock, flags);
@@ -682,7 +687,7 @@ 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 +709,7 @@ 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 +722,14 @@ 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,
--
2.15.0
next prev parent reply other threads:[~2017-12-06 0:59 UTC|newest]
Thread overview: 127+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-06 0:40 [PATCH v4 00/73] XArray version 4 Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 01/73] xfs: Rename xa_ elements to ail_ Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 02/73] xarray: Add the xa_lock to the radix_tree_root Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 03/73] page cache: Use xa_lock Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 04/73] xarray: Replace exceptional entries Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 05/73] xarray: Change definition of sibling entries Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 06/73] xarray: Add definition of struct xarray Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 07/73] xarray: Define struct xa_node Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 08/73] xarray: Add documentation Matthew Wilcox
2017-12-11 23:10 ` Randy Dunlap
2017-12-15 4:22 ` Matthew Wilcox
2017-12-15 12:34 ` Naming of tag operations in the XArray Matthew Wilcox
2017-12-19 0:16 ` Randy Dunlap
2017-12-15 17:10 ` Storing errors " Matthew Wilcox
2017-12-19 0:27 ` Randy Dunlap
2017-12-06 0:40 ` [PATCH v4 09/73] xarray: Add xa_load Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 10/73] xarray: Add xa_get_tag, xa_set_tag and xa_clear_tag Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 11/73] xarray: Add xa_store Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 12/73] xarray: Add xa_cmpxchg Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 13/73] xarray: Add xa_for_each Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 14/73] xarray: Add xas_for_each_tag Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 15/73] xarray: Add xa_get_entries, xa_get_tagged and xa_get_maybe_tag Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 16/73] xarray: Add xa_destroy Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 17/73] xarray: Add xas_next and xas_prev Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 18/73] xarray: Add xas_create_range Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 19/73] xarray: Add MAINTAINERS entry Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 20/73] idr: Convert to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 21/73] ida: " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 22/73] page cache: Convert hole search " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 23/73] page cache: Add page_cache_range_empty function Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 24/73] page cache: Add and replace pages using the XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 25/73] page cache: Convert page deletion to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 26/73] page cache: Convert page cache lookups " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 27/73] page cache: Convert delete_batch " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 28/73] page cache: Remove stray radix comment Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 29/73] mm: Convert page-writeback to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 30/73] mm: Convert workingset " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 31/73] mm: Convert truncate " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 32/73] mm: Convert add_to_swap_cache " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 33/73] mm: Convert delete_from_swap_cache " Matthew Wilcox
2017-12-06 0:41 ` Matthew Wilcox [this message]
2017-12-06 0:41 ` [PATCH v4 35/73] mm: Convert __do_page_cache_readahead " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 36/73] mm: Convert page migration " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 37/73] mm: Convert huge_memory " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 38/73] mm: Convert collapse_shmem " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 39/73] mm: Convert khugepaged_scan_shmem " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 40/73] pagevec: Use xa_tag_t Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 41/73] shmem: Convert replace to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 42/73] shmem: Convert shmem_confirm_swap " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 43/73] shmem: Convert find_swap_entry " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 44/73] shmem: Convert shmem_tag_pins " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 45/73] shmem: Convert shmem_wait_for_pins " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 46/73] shmem: Convert shmem_add_to_page_cache " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 47/73] shmem: Convert shmem_alloc_hugepage " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 48/73] shmem: Convert shmem_free_swap " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 49/73] shmem: Convert shmem_partial_swap_usage " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 50/73] shmem: Comment fixups Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 51/73] btrfs: Convert page cache to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 52/73] fs: Convert buffer " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 53/73] fs: Convert writeback " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 54/73] nilfs2: Convert " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 55/73] f2fs: " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 56/73] lustre: " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 57/73] dax: Convert dax_unlock_mapping_entry " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 58/73] dax: Convert lock_slot " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 59/73] dax: More XArray conversion Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 60/73] dax: Convert __dax_invalidate_mapping_entry to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 61/73] dax: Convert dax_writeback_one " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 62/73] dax: Convert dax_insert_pfn_mkwrite " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 63/73] dax: Convert dax_insert_mapping_entry " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 64/73] dax: Convert grab_mapping_entry " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 65/73] dax: Fix sparse warning Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 66/73] page cache: Finish XArray conversion Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 67/73] vmalloc: Convert to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 68/73] brd: " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 69/73] xfs: Convert m_perag_tree " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 70/73] xfs: Convert pag_ici_root " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 71/73] xfs: Convert xfs dquot " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 72/73] xfs: Convert mru cache " Matthew Wilcox
2017-12-06 1:36 ` Dave Chinner
2017-12-06 2:02 ` Matthew Wilcox
2017-12-06 3:14 ` Dave Chinner
2017-12-06 4:45 ` Matthew Wilcox
2017-12-06 4:52 ` Matthew Wilcox
2017-12-06 8:44 ` Dave Chinner
2017-12-06 14:06 ` Matthew Wilcox
2017-12-07 0:38 ` Dave Chinner
2017-12-08 23:01 ` Matthew Wilcox
2017-12-10 23:57 ` Dave Chinner
2017-12-11 4:23 ` Matthew Wilcox
2017-12-11 21:55 ` Dave Chinner
2017-12-07 16:06 ` Theodore Ts'o
2017-12-07 22:22 ` Dave Chinner
2017-12-08 4:45 ` Byungchul Park
2017-12-08 7:25 ` Dave Chinner
2017-12-08 9:27 ` Byungchul Park
2017-12-08 17:35 ` Alan Stern
2017-12-08 22:36 ` Dave Chinner
2017-12-09 17:00 ` Joe Perches
2017-12-11 21:43 ` Dave Chinner
2017-12-11 22:12 ` Joe Perches
2017-12-11 22:43 ` Matthew Wilcox
2017-12-11 23:46 ` Joe Perches
2017-12-12 15:51 ` Alan Stern
2017-12-14 18:23 ` Joe Perches
2017-12-17 1:26 ` [RFC patch] checkpatch: Add a test for long function definitions (>200 lines) Joe Perches
2017-12-17 21:46 ` Linus Torvalds
2017-12-17 22:22 ` Joe Perches
2017-12-17 22:33 ` Luc Van Oostenryck
2017-12-11 23:38 ` [PATCH v4 72/73] xfs: Convert mru cache to XArray Dave Chinner
2017-12-21 12:05 ` Knut Omang
2017-12-07 22:38 ` Lockdep is less useful than it was Matthew Wilcox
2017-12-07 22:39 ` Matthew Wilcox
2017-12-08 0:14 ` Dave Chinner
2017-12-08 15:27 ` Theodore Ts'o
2017-12-08 18:14 ` Matthew Wilcox
2017-12-08 22:47 ` Dave Chinner
2017-12-06 0:41 ` [PATCH v4 73/73] usb: Convert xhci-mem to XArray Matthew Wilcox
2017-12-06 1:45 ` [PATCH v4 00/73] XArray version 4 Dave Chinner
2017-12-06 1:51 ` Dave Chinner
2017-12-06 1:53 ` Matthew Wilcox
2017-12-06 2:17 ` Dave Chinner
2017-12-06 2:27 ` Matthew Wilcox
2017-12-06 2:05 ` Matthew Wilcox
2017-12-06 2:38 ` Dave Chinner
2017-12-06 23:58 ` Ross Zwisler
2017-12-07 0:13 ` Matthew Wilcox
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