On Thu 11-06-15 15:41:13, Josef Bacik wrote:
> 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@xxxxxx>
Looks good. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/inode.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/fs/inode.c b/fs/inode.c
> index d1e6598..53a1224 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -574,6 +574,7 @@ static void dispose_list(struct list_head *head)
> list_del_init(&inode->i_lru);
>
> evict(inode);
> + cond_resched();
> }
> }
>
> @@ -591,6 +592,7 @@ 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))
> @@ -606,6 +608,18 @@ 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);
>
> --
> 2.1.0
>
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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