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Date:   Sun, 26 Mar 2023 13:53:27 +0900
From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     Liu Shixin <liushixin2@huawei.com>
Cc:     Seth Jennings <sjenning@redhat.com>,
        Dan Streetman <ddstreet@ieee.org>,
        Vitaly Wool <vitaly.wool@konsulko.com>,
        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, Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: Re: [PATCH -next v7 2/4] mm/zswap: skip invalid or unchanged
 parameter
Message-ID: <20230326045327.GE3269998@google.com>
References: <20230325071420.2246461-1-liushixin2@huawei.com>
 <20230325071420.2246461-3-liushixin2@huawei.com>
 <20230326031723.GD3269998@google.com>
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On (23/03/26 12:17), Sergey Senozhatsky wrote:
> On (23/03/25 15:14), Liu Shixin wrote:
> >  static int zswap_enabled_param_set(const char *val,
> >  				   const struct kernel_param *kp)
> >  {
> > +	bool res;
> > +
> > +	if (kstrtobool(val, &res))
> > +		return -EINVAL;
> > +
> > +	/* no change required */
> > +	if (res == *(bool *)kp->arg)
> > +		return 0;
> 
> Bool kernel param can be any of these letters 'YyTt1NnFf0'. Doing things
> to kp->arg outside of kernel/params.c is not going to be easy, let's not
> even try.

Please disregard my previous email. kp->arg is always true or false
at this point. I'd still prefer to not do kp->arg in zswap.