Re: [PATCH v3 1/7] fs: Use a percpu_counter to track nr_dentry

[Nick Piggin]

On Friday 12 December 2008 09:38, Eric Dumazet wrote:
> Adding a percpu_counter nr_dentry avoids cache line ping pongs
> between cpus to maintain this metric, and dcache_lock is
> no more needed to protect dentry_stat.nr_dentry
>
> We centralize nr_dentry updates at the right place :
> - increments in d_alloc()
> - decrements in d_free()
>
> d_alloc() can avoid taking dcache_lock if parent is NULL
>
> ("socketallocbench -n8" result : 27.5s to 25s)

Seems like a good idea.


> @@ -696,7 +712,7 @@ static void shrink_dcache_for_umount_subtree(struct
> dentry *dentry) * otherwise we ascend to the parent and move to the
>  			 * next sibling if there is one */
>  			if (!parent)
> -				goto out;
> +				return;
>
>  			dentry = parent;
>

Andrew doesn't like return from middle of function.
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