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Date:   Thu, 23 Mar 2023 08:59:27 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Vitaly Wool <vitaly.wool@konsulko.com>
Cc:     Liu Shixin <liushixin2@huawei.com>,
        Seth Jennings <sjenning@redhat.com>,
        Dan Streetman <ddstreet@ieee.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Christoph Hellwig <hch@lst.de>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCH -next v6 2/2] mm/zswap: delay the initializaton of zswap
Message-ID: <20230323075927.GB20444@lst.de>
References: <20230322102006.780624-1-liushixin2@huawei.com> <20230322102006.780624-3-liushixin2@huawei.com> <CAM4kBBJT1xSGe7KthBvBLstZ43cPP-PDKE7a-6hC5Fn6TneL0g@mail.gmail.com>
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On Wed, Mar 22, 2023 at 06:17:12PM +0100, Vitaly Wool wrote:
> On Wed, Mar 22, 2023 at 10:30 AM Liu Shixin <liushixin2@huawei.com> wrote:
> >
> > Since some users may not use zswap, the zswap_pool is wasted. Save memory
> > by delaying the initialization of zswap until enabled.
> 
> To be honest, I'm not a huge fan of this. Would enabling zswap module
> build instead solve your problem?

making zswap build modular would be a mess.  It is core MM infrastructure
and now we'd need to start dealing with adding and removing it at
runtime as well as module refcounting.