From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [PATCH v4 8/8] zram: enable contextless compression alg in zram
Date: Thu, 15 Oct 2015 11:05:49 +0900
Message-ID: <20151015020549.GE1735@swordfish>
References: <1444808304-29320-1-git-send-email-iamjoonsoo.kim@lge.com>
 <1444808304-29320-9-git-send-email-iamjoonsoo.kim@lge.com>
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Cc: Andrew Morton <akpm@linux-foundation.org>,
	Minchan Kim <minchan@kernel.org>,
	Nitin Gupta <ngupta@vflare.org>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	Stephan Mueller <smueller@chronox.de>,
	linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>
To: Joonsoo Kim <js1304@gmail.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
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On (10/14/15 16:38), Joonsoo Kim wrote:
[..]
> @@ -352,6 +352,7 @@ static ssize_t comp_algorithm_show(struct device *dev,
>  	size_t sz;
>  	struct zram *zram = dev_to_zram(dev);
>  
> +	deprecated_attr_warn("comp_algorithm");
>  	down_read(&zram->init_lock);
>  	sz = zcomp_available_show(zram->compressor, buf);
>  	up_read(&zram->init_lock);

oh, one more thing.

deprecated_attr_warn() should come with `Documentation/ABI/obsolete/sysfs-block-zram' update.
something like:

diff --git a/Documentation/ABI/obsolete/sysfs-block-zram b/Documentation/ABI/obsolete/sysfs-block-zram
index 720ea92..ad5b59d 100644
--- a/Documentation/ABI/obsolete/sysfs-block-zram
+++ b/Documentation/ABI/obsolete/sysfs-block-zram
@@ -117,3 +117,14 @@ Description:
                Downgraded to write-only node: so it's possible to set new
                value only; its current value is stored in zram<id>/mm_stat
                node.
+
+What:          /sys/block/zram<id>/comp_algorithm
+Date:          XXX
+Contact:       XXX
+Description:
+               The comp_algorithm file is read/write and provides information
+               on available, currently selected compression algorithm (read
+               operation) and lets one to change the compression algorithm
+               (write operation).
+               Downgraded to write-only node: use `/proc/crypto' to get the
+               list of supported compression algorithms.


---


And I guess Cc `Jonathan Corbet <corbet@lwn.net>' (doc maintainer) and
'linux-api@vger.kernel.org' will be the right thing to do here.

	-ss