All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Minchan Kim <minchan@kernel.org>, Rui Salvaterra <rsalvaterra@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	ngupta@vflare.org, sergey.senozhatsky.work@gmail.com,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4] zram: break the strict dependency from lzo
Date: Thu, 29 Oct 2020 03:59:27 +0900	[thread overview]
Message-ID: <20201028185927.GB128655@google.com> (raw)
In-Reply-To: <20201028115921.848-1-rsalvaterra@gmail.com>

Cc-ing Andrew

message-id: 20201028115921.848-1-rsalvaterra@gmail.com

On (20/10/28 11:59), Rui Salvaterra wrote:
> There's nothing special about zram and lzo. It works just fine without it, so
> as long as at least one of the other supported compression algorithms is
> selected.
> 
> Suggested-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
> Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>

Minchan, I'm fine with the change.

Two things from my side:

1) The commit message, probably, can be a bit more informative. Something
like this?

	ZRAM always enables CRYPTO_LZO because lzo-rle is the hardcoded
	fallback compression algorithm, which means that on systems where
	ZRAM always use, for instance, CRYPTO_ZSTD lzo kernel module
	becomes unneeded. This patch removes the hardcoded lzo-lre
	dependency, instead ZRAM picks the first supported CRYPTO
	compression algorithm, should it be ZSTD or LZ4, etc; and only
	forcibly enables CRYPTO_LZO (previous behaviour) if none of the
	alternative algorithms were selected.


2) The ZRAM_AUTOSEL_ALGO allows to deselect CRYPTO_LZO only if
CRYPTO_LZ4/CRYPTO_LZ4HC/CRYPTO_842/CRYPTO_ZSTD are compiled in (=y).
If any of the algorithms is selected as a module (=m) then CRYPTO_LZO
is selected as the default algorithm. Apparently depends on !(CONFIG_FOO)
means depends on !(CONFIG_FOO=y).

It appears that the below change fixes it, but it looks a bit ugly.

---
diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 141ce0ebad06..f2fd34de9200 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -15,7 +15,7 @@ config ZRAM
 
 config ZRAM_AUTOSEL_ALGO
 	def_bool y
-	depends on ZRAM && !(CRYPTO_LZ4 || CRYPTO_LZ4HC || CRYPTO_842 || CRYPTO_ZSTD)
+	depends on ZRAM && !(CRYPTO_LZ4=m || CRYPTO_LZ4HC=m || CRYPTO_842=m || CRYPTO_ZSTD=m || CRYPTO_LZ4=y || CRYPTO_LZ4HC=y || CRYPTO_842=y || CRYPTO_ZSTD=y)
 	select CRYPTO_LZO
 
 config ZRAM_WRITEBACK
---

	-ss

  reply	other threads:[~2020-10-29  2:03 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-28 11:59 [PATCH v4] zram: break the strict dependency from lzo Rui Salvaterra
2020-10-28 18:59 ` Sergey Senozhatsky [this message]
2020-11-03 21:28   ` Minchan Kim
2020-11-04 14:12     ` Rui Salvaterra
2020-11-04 20:41       ` Minchan Kim
2020-11-14  0:49         ` Sergey Senozhatsky

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201028185927.GB128655@google.com \
    --to=sergey.senozhatsky.work@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=minchan@kernel.org \
    --cc=ngupta@vflare.org \
    --cc=rsalvaterra@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.