inode: don't softlockup when evicting inodes (ac05fbb4) · Commits · 戴 / test

On a box with a lot of ram (148gb) I can make the box softlockup after running an fs_mark job that creates hundreds of millions of empty files. This is because we never generate enough memory pressure to keep the number of inodes on our unused list low, so when we go to unmount we have to evict ~100 million inodes. This makes one processor a very unhappy person, so add a cond_resched() in dispose_list() and if we need a resched when processing the s_inodes list do that and run dispose_list() on what we've currently culled. Thanks, Signed-off-by:

Josef Bacik <jbacik@fb.com> Reviewed-by:

Jan Kara <jack@suse.cz>

fs/inode.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -575,6 +575,7 @@ static void dispose_list(struct list_head *head)
		list_del_init(&inode->i_lru);

		evict(inode);
		cond_resched();
		}
		}

		@@ -592,6 +593,7 @@ void evict_inodes(struct super_block *sb)
		struct inode inode, next;
		LIST_HEAD(dispose);

		again:
		spin_lock(&sb->s_inode_list_lock);
		list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
		if (atomic_read(&inode->i_count))
		@@ -607,6 +609,18 @@ void evict_inodes(struct super_block *sb)
		inode_lru_list_del(inode);
		spin_unlock(&inode->i_lock);
		list_add(&inode->i_lru, &dispose);

		/*
		* We can have a ton of inodes to evict at unmount time given
		* enough memory, check to see if we need to go to sleep for a
		* bit so we don't livelock.
		*/
		if (need_resched()) {
		spin_unlock(&sb->s_inode_list_lock);
		cond_resched();
		dispose_list(&dispose);
		goto again;
		}
		}
		spin_unlock(&sb->s_inode_list_lock);

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