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Date:   Mon, 15 Aug 2022 11:52:47 +0900
From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     Alexey Romanov <avromanov@sberdevices.ru>
Cc:     minchan@kernel.org, senozhatsky@chromium.org, ngupta@vflare.org,
        akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, kernel@sberdevices.ru
Subject: Re: [PATCH v1 1/2] zsmalloc: zs_object_copy: add clarifying comment
Message-ID: <Yvm0//iPcvbW1M55@google.com>
References: <20220811153755.16102-1-avromanov@sberdevices.ru>
 <20220811153755.16102-2-avromanov@sberdevices.ru>
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On (22/08/11 18:37), Alexey Romanov wrote:
> @@ -1564,6 +1564,12 @@ static void zs_object_copy(struct size_class *class, unsigned long dst,
>  		d_off += size;
>  		d_size -= size;
>  
> +		/* Calling kunmap_atomic(d_addr) is necessary. kunmap_atomic() calls
> +		 * must occurs in reverse order of calls to kmap_atomic().
> +		 * So, to call kunmap_atomic(s_addr) we should first call kunmap_atomic(d_addr).
> +		 * For more details see:
> +		 * https://lore.kernel.org/linux-mm/5512421D.4000603@samsung.com/
> +		 */

I'd drop the link part, Emails are not documentation, kmap_atomic
is documented in Documentation/mm/highmem