Re: [PATCH powerpc 2/2] kfree the cache name of pgtable cache if SLUB is used

On 06/29/2012 08:45 AM, Benjamin Herrenschmidt wrote:

On Mon, 2012-06-25 at 17:54 +0800, Li Zhong wrote:

quoted

diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index 620b7ac..c9d2a7f 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c

@@ -130,6 +130,9 @@ void pgtable_cache_add(unsigned shift, void

(*ctor)(void *))
 	align = max_t(unsigned long, align, minalign);
 	name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
 	new = kmem_cache_create(name, table_size, align, 0, ctor);
+#ifdef CONFIG_SLUB
+	kfree(name); /* SLUB duplicates the cache name */
+#endif
 	PGT_CACHE(shift) = new;
 
 	pr_debug("Allocated pgtable cache for order %d\n", shift);

This is very gross ... and fragile. Also the subtle difference in
semantics between SLUB and SLAB is a VERY BAD IDEA.

I agree.

I reckon you should make the other allocators all copy the name
instead.

Thank you for the suggestion. I will do it in the next version.

Thanks, Zhong

Ben.