From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlastimil Babka Subject: [PATCH v4 3/6] dcache: allocate external names from reclaimable kmalloc caches Date: Tue, 31 Jul 2018 11:06:46 +0200 Message-ID: <20180731090649.16028-4-vbabka@suse.cz> References: <20180731090649.16028-1-vbabka@suse.cz> Return-path: In-Reply-To: <20180731090649.16028-1-vbabka@suse.cz> Sender: linux-kernel-owner@vger.kernel.org To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Roman Gushchin , Michal Hocko , Johannes Weiner , Christoph Lameter , David Rientjes , Joonsoo Kim , Mel Gorman , Matthew Wilcox , Vlastimil Babka List-Id: linux-api@vger.kernel.org We can use the newly introduced kmalloc-reclaimable-X caches, to allocate external names in dcache, which will take care of the proper accounting automatically, and also improve anti-fragmentation page grouping. This effectively reverts commit f1782c9bc547 ("dcache: account external names as indirectly reclaimable memory") and instead passes __GFP_RECLAIMABLE to kmalloc(). The accounting thus moves from NR_INDIRECTLY_RECLAIMABLE_BYTES to NR_SLAB_RECLAIMABLE, which is also considered in MemAvailable calculation and overcommit decisions. Signed-off-by: Vlastimil Babka Acked-by: Mel Gorman Acked-by: Roman Gushchin --- fs/dcache.c | 38 +++++++++----------------------------- 1 file changed, 9 insertions(+), 29 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index 0e8e5de3c48a..518c9ed8db8c 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -257,24 +257,10 @@ static void __d_free(struct rcu_head *head) kmem_cache_free(dentry_cache, dentry); } -static void __d_free_external_name(struct rcu_head *head) -{ - struct external_name *name = container_of(head, struct external_name, - u.head); - - mod_node_page_state(page_pgdat(virt_to_page(name)), - NR_INDIRECTLY_RECLAIMABLE_BYTES, - -ksize(name)); - - kfree(name); -} - static void __d_free_external(struct rcu_head *head) { struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu); - - __d_free_external_name(&external_name(dentry)->u.head); - + kfree(external_name(dentry)); kmem_cache_free(dentry_cache, dentry); } @@ -305,7 +291,7 @@ void release_dentry_name_snapshot(struct name_snapshot *name) struct external_name *p; p = container_of(name->name, struct external_name, name[0]); if (unlikely(atomic_dec_and_test(&p->u.count))) - call_rcu(&p->u.head, __d_free_external_name); + kfree_rcu(p, u.head); } } EXPORT_SYMBOL(release_dentry_name_snapshot); @@ -1608,7 +1594,6 @@ EXPORT_SYMBOL(d_invalidate); struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) { - struct external_name *ext = NULL; struct dentry *dentry; char *dname; int err; @@ -1629,14 +1614,15 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) dname = dentry->d_iname; } else if (name->len > DNAME_INLINE_LEN-1) { size_t size = offsetof(struct external_name, name[1]); - - ext = kmalloc(size + name->len, GFP_KERNEL_ACCOUNT); - if (!ext) { + struct external_name *p = kmalloc(size + name->len, + GFP_KERNEL_ACCOUNT | + __GFP_RECLAIMABLE); + if (!p) { kmem_cache_free(dentry_cache, dentry); return NULL; } - atomic_set(&ext->u.count, 1); - dname = ext->name; + atomic_set(&p->u.count, 1); + dname = p->name; } else { dname = dentry->d_iname; } @@ -1675,12 +1661,6 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) } } - if (unlikely(ext)) { - pg_data_t *pgdat = page_pgdat(virt_to_page(ext)); - mod_node_page_state(pgdat, NR_INDIRECTLY_RECLAIMABLE_BYTES, - ksize(ext)); - } - this_cpu_inc(nr_dentry); return dentry; @@ -2761,7 +2741,7 @@ static void copy_name(struct dentry *dentry, struct dentry *target) dentry->d_name.hash_len = target->d_name.hash_len; } if (old_name && likely(atomic_dec_and_test(&old_name->u.count))) - call_rcu(&old_name->u.head, __d_free_external_name); + kfree_rcu(old_name, u.head); } /* -- 2.18.0