Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 17 Jun 2021 17:44:18 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     Miaohe Lin <linmiaohe@huawei.com>
Cc:     akpm@linux-foundation.org, sjenning@redhat.com, ddstreet@ieee.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v2 2/2] mm/zbud: don't export any zbud API
Message-ID: <YMvsYm8b+yTIrqBC@archlinux-ax161>
References: <20210608114515.206992-1-linmiaohe@huawei.com>
 <20210608114515.206992-3-linmiaohe@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210608114515.206992-3-linmiaohe@huawei.com>
Precedence: bulk

On Tue, Jun 08, 2021 at 07:45:15PM +0800, Miaohe Lin wrote:
> The zbud doesn't need to export any API and it is meant to be used via
> zpool API since the commit 12d79d64bfd3 ("mm/zpool: update zswap to use
> zpool"). So we can remove the unneeded zbud.h and move down zpool API
> to avoid any forward declaration.
> 
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>

This patch causes several new warnings when CONFIG_ZPOOL is disabled:

mm/zbud.c:222:26: warning: unused function 'zbud_create_pool' [-Wunused-function]
mm/zbud.c:246:13: warning: unused function 'zbud_destroy_pool' [-Wunused-function]
mm/zbud.c:270:12: warning: unused function 'zbud_alloc' [-Wunused-function]
mm/zbud.c:345:13: warning: unused function 'zbud_free' [-Wunused-function]
mm/zbud.c:417:12: warning: unused function 'zbud_reclaim_page' [-Wunused-function]
mm/zbud.c:499:14: warning: unused function 'zbud_map' [-Wunused-function]
mm/zbud.c:509:13: warning: unused function 'zbud_unmap' [-Wunused-function]
mm/zbud.c:520:12: warning: unused function 'zbud_get_pool_size' [-Wunused-function]

It seems to me like all of these functions should be sunk into their
callers and eliminated entirely as part of this refactoring. I took a
whack at it but got lost with the kernel docs so someone who is familiar
with this should probably do it.

Cheers,
Nathan