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Date:   Fri, 25 Mar 2022 14:47:55 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     xkernel.wang@foxmail.com
Cc:     glider@google.com, andreyknvl@gmail.com, elver@google.com,
        dvyukov@google.com, ryabinin.a.a@gmail.com,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] lib/test_meminit: optimize
 do_kmem_cache_rcu_persistent() test
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On Wed, 23 Mar 2022 11:48:24 +0800 xkernel.wang@foxmail.com wrote:

> From: Xiaoke Wang <xkernel.wang@foxmail.com>
> 
> To make the test more robust, there are the following changes:
> 1. add a check for the return value of kmem_cache_alloc().
> 2. properly release the object `buf` on several error paths.
> 3. release the objects of `used_objects` if we never hit `saved_ptr`.
> 4. destroy the created cache by default.
> 
> ...
>
> --- a/lib/test_meminit.c
> +++ b/lib/test_meminit.c
> @@ -300,13 +300,18 @@ static int __init do_kmem_cache_rcu_persistent(int size, int *total_failures)
>  	c = kmem_cache_create("test_cache", size, size, SLAB_TYPESAFE_BY_RCU,
>  			      NULL);
>  	buf = kmem_cache_alloc(c, GFP_KERNEL);
> +	if (!buf)
> +		goto out;

OK, Normally we don't bother checking allocation success in __init
code, but this test can run via modprobe, so I guess checking is the
right thing to do.