Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753090AbbLVHe6 (ORCPT ); Tue, 22 Dec 2015 02:34:58 -0500 Received: from mail.kernel.org ([198.145.29.136]:47249 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751819AbbLVHe4 (ORCPT ); Tue, 22 Dec 2015 02:34:56 -0500 Date: Mon, 21 Dec 2015 23:34:53 -0800 From: Jaegeuk Kim To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH 1/2] f2fs: use atomic variable for total_extent_tree Message-ID: <20151222073453.GA20735@jaegeuk.local> References: <1450755521-20015-1-git-send-email-jaegeuk@kernel.org> <00be01d13c79$a3db6970$eb923c50$@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <00be01d13c79$a3db6970$eb923c50$@samsung.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6291 Lines: 154 On Tue, Dec 22, 2015 at 01:28:09PM +0800, Chao Yu wrote: > Hi Jaegeuk, > > > -----Original Message----- > > From: Jaegeuk Kim [mailto:jaegeuk@kernel.org] > > Sent: Tuesday, December 22, 2015 11:39 AM > > To: linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org; > > linux-f2fs-devel@lists.sourceforge.net > > Cc: Jaegeuk Kim > > Subject: [f2fs-dev] [PATCH 1/2] f2fs: use atomic variable for total_extent_tree > > > > It would be better to use atomic variable for total_extent_tree. > > total_extent_tree was protected by extent_tree_lock semaphore, so intention here > is to make related calculation in available_free_memory or update_general_status > more accurate, right? Moreover, another major thing is to specify it is atomic along with other extent counts. Thanks, > > Thanks, > > > > > Signed-off-by: Jaegeuk Kim > > --- > > fs/f2fs/debug.c | 5 +++-- > > fs/f2fs/extent_cache.c | 8 ++++---- > > fs/f2fs/f2fs.h | 2 +- > > fs/f2fs/node.c | 3 ++- > > fs/f2fs/shrinker.c | 3 ++- > > 5 files changed, 12 insertions(+), 9 deletions(-) > > > > diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c > > index bb307e6..ed5dfcc 100644 > > --- a/fs/f2fs/debug.c > > +++ b/fs/f2fs/debug.c > > @@ -38,7 +38,7 @@ static void update_general_status(struct f2fs_sb_info *sbi) > > si->hit_rbtree = atomic64_read(&sbi->read_hit_rbtree); > > si->hit_total = si->hit_largest + si->hit_cached + si->hit_rbtree; > > si->total_ext = atomic64_read(&sbi->total_hit_ext); > > - si->ext_tree = sbi->total_ext_tree; > > + si->ext_tree = atomic_read(&sbi->total_ext_tree); > > si->ext_node = atomic_read(&sbi->total_ext_node); > > si->ndirty_node = get_pages(sbi, F2FS_DIRTY_NODES); > > si->ndirty_dent = get_pages(sbi, F2FS_DIRTY_DENTS); > > @@ -193,7 +193,8 @@ get_cache: > > si->cache_mem += si->inmem_pages * sizeof(struct inmem_pages); > > for (i = 0; i <= UPDATE_INO; i++) > > si->cache_mem += sbi->im[i].ino_num * sizeof(struct ino_entry); > > - si->cache_mem += sbi->total_ext_tree * sizeof(struct extent_tree); > > + si->cache_mem += atomic_read(&sbi->total_ext_tree) * > > + sizeof(struct extent_tree); > > si->cache_mem += atomic_read(&sbi->total_ext_node) * > > sizeof(struct extent_node); > > > > diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c > > index e86e9f1e..0e97d6af 100644 > > --- a/fs/f2fs/extent_cache.c > > +++ b/fs/f2fs/extent_cache.c > > @@ -70,7 +70,7 @@ static struct extent_tree *__grab_extent_tree(struct inode *inode) > > rwlock_init(&et->lock); > > atomic_set(&et->refcount, 0); > > et->count = 0; > > - sbi->total_ext_tree++; > > + atomic_inc(&sbi->total_ext_tree); > > } > > atomic_inc(&et->refcount); > > up_write(&sbi->extent_tree_lock); > > @@ -570,7 +570,7 @@ unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int > > nr_shrink) > > > > radix_tree_delete(root, et->ino); > > kmem_cache_free(extent_tree_slab, et); > > - sbi->total_ext_tree--; > > + atomic_dec(&sbi->total_ext_tree); > > tree_cnt++; > > > > if (node_cnt + tree_cnt >= nr_shrink) > > @@ -663,7 +663,7 @@ void f2fs_destroy_extent_tree(struct inode *inode) > > f2fs_bug_on(sbi, atomic_read(&et->refcount) || et->count); > > radix_tree_delete(&sbi->extent_tree_root, inode->i_ino); > > kmem_cache_free(extent_tree_slab, et); > > - sbi->total_ext_tree--; > > + atomic_dec(&sbi->total_ext_tree); > > up_write(&sbi->extent_tree_lock); > > > > F2FS_I(inode)->extent_tree = NULL; > > @@ -715,7 +715,7 @@ void init_extent_cache_info(struct f2fs_sb_info *sbi) > > init_rwsem(&sbi->extent_tree_lock); > > INIT_LIST_HEAD(&sbi->extent_list); > > spin_lock_init(&sbi->extent_lock); > > - sbi->total_ext_tree = 0; > > + atomic_set(&sbi->total_ext_tree, 0); > > atomic_set(&sbi->total_ext_node, 0); > > } > > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > index 19beabe..a7f6191 100644 > > --- a/fs/f2fs/f2fs.h > > +++ b/fs/f2fs/f2fs.h > > @@ -762,7 +762,7 @@ struct f2fs_sb_info { > > struct rw_semaphore extent_tree_lock; /* locking extent radix tree */ > > struct list_head extent_list; /* lru list for shrinker */ > > spinlock_t extent_lock; /* locking extent lru list */ > > - int total_ext_tree; /* extent tree count */ > > + atomic_t total_ext_tree; /* extent tree count */ > > atomic_t total_ext_node; /* extent info count */ > > > > /* basic filesystem units */ > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > > index d842b19..6cc8ac7 100644 > > --- a/fs/f2fs/node.c > > +++ b/fs/f2fs/node.c > > @@ -65,7 +65,8 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type) > > sizeof(struct ino_entry)) >> PAGE_CACHE_SHIFT; > > res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1); > > } else if (type == EXTENT_CACHE) { > > - mem_size = (sbi->total_ext_tree * sizeof(struct extent_tree) + > > + mem_size = (atomic_read(&sbi->total_ext_tree) * > > + sizeof(struct extent_tree) + > > atomic_read(&sbi->total_ext_node) * > > sizeof(struct extent_node)) >> PAGE_CACHE_SHIFT; > > res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1); > > diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c > > index da0d8e0..a11e099 100644 > > --- a/fs/f2fs/shrinker.c > > +++ b/fs/f2fs/shrinker.c > > @@ -32,7 +32,8 @@ static unsigned long __count_free_nids(struct f2fs_sb_info *sbi) > > > > static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi) > > { > > - return sbi->total_ext_tree + atomic_read(&sbi->total_ext_node); > > + return atomic_read(&sbi->total_ext_tree) + > > + atomic_read(&sbi->total_ext_node); > > } > > > > unsigned long f2fs_shrink_count(struct shrinker *shrink, > > -- > > 2.5.4 (Apple Git-61) > > > > > > ------------------------------------------------------------------------------ > > _______________________________________________ > > Linux-f2fs-devel mailing list > > Linux-f2fs-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/