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Subject: Re: [PATCH v3] zswap: allow setting default status, compressor and
 allocator in Kconfig
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Seth Jennings <sjenning@redhat.com>,
        Dan Streetman <ddstreet@ieee.org>,
        Vitaly Wool <vitalywool@gmail.com>,
        Vlastimil Babka <vbabka@suse.cz>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <20191108235107.2837339-1-mail@maciej.szmigiero.name>
 <20191111153931.199e4c729bfad2e8201e75a5@linux-foundation.org>
From:   "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
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Message-ID: <c56656a1-07bb-a7f9-6956-53d58d61c7ee@maciej.szmigiero.name>
Date:   Tue, 12 Nov 2019 00:46:01 +0100
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On 12.11.2019 00:39, Andrew Morton wrote:
> On Sat,  9 Nov 2019 00:51:07 +0100 "Maciej S. Szmigiero" <mail@maciej.szmigiero.name> wrote:
> 
>> The compressed cache for swap pages (zswap) currently needs from 1 to 3
>> extra kernel command line parameters in order to make it work: it has to be
>> enabled by adding a "zswap.enabled=1" command line parameter and if one
>> wants a different compressor or pool allocator than the default lzo / zbud
>> combination then these choices also need to be specified on the kernel
>> command line in additional parameters.
>>
>> Using a different compressor and allocator for zswap is actually pretty
>> common as guides often recommend using the lz4 / z3fold pair instead of
>> the default one.
>> In such case it is also necessary to remember to enable the appropriate
>> compression algorithm and pool allocator in the kernel config manually.
>>
>> Let's avoid the need for adding these kernel command line parameters and
>> automatically pull in the dependencies for the selected compressor
>> algorithm and pool allocator by adding an appropriate default switches to
>> Kconfig.
>>
>> The default values for these options match what the code was using
>> previously as its defaults.
> 
> Shouldn't there be a Documentation/ update along with this change?
> 

Good point, will update Documentation/, too, in a respin.

Thanks,
Maciej