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From: neidhard.kim@lge.com (Jongsung Kim)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM:mm: fix kmap_atomic_to_page
Date: Tue, 13 Oct 2015 11:06:44 +0900	[thread overview]
Message-ID: <561C6734.7010509@lge.com> (raw)
In-Reply-To: <5778996.I0Vmityi0g@wuerfel>

On 10/12/2015 06:27 PM, Arnd Bergmann wrote:
> How about changing the zcomp code to pass the page pointer instead of the kernel space pointer? That would avoid having to do the kmap_atomic, which can itself be expensive on 32-bit machines and should not be needed here if you have a HW DMA engine doing the compression. Arnd 

Mainline zram uses lzo / lz4 library functions as backend. Using kmap_atomic and passing address look reasonable.

WARNING: multiple messages have this Message-ID (diff)
From: Jongsung Kim <neidhard.kim@lge.com>
To: Arnd Bergmann <arnd@arndb.de>, linux-arm-kernel@lists.infradead.org
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>,
	Nicolas Pitre <nicolas.pitre@linaro.org>,
	Gunho Lee <gunho.lee@lge.com>, Chanho Min <chanho.min@lge.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ARM:mm: fix kmap_atomic_to_page
Date: Tue, 13 Oct 2015 11:06:44 +0900	[thread overview]
Message-ID: <561C6734.7010509@lge.com> (raw)
In-Reply-To: <5778996.I0Vmityi0g@wuerfel>

On 10/12/2015 06:27 PM, Arnd Bergmann wrote:
> How about changing the zcomp code to pass the page pointer instead of the kernel space pointer? That would avoid having to do the kmap_atomic, which can itself be expensive on 32-bit machines and should not be needed here if you have a HW DMA engine doing the compression. Arnd 

Mainline zram uses lzo / lz4 library functions as backend. Using kmap_atomic and passing address look reasonable.

  reply	other threads:[~2015-10-13  2:06 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-06 11:09 [PATCH] ARM:mm: fix kmap_atomic_to_page Chanho Min
2015-10-06 11:09 ` Chanho Min
2015-10-06 19:28 ` Russell King - ARM Linux
2015-10-06 19:28   ` Russell King - ARM Linux
2015-10-07  1:37   ` Nicolas Pitre
2015-10-07  1:37     ` Nicolas Pitre
2015-10-07  3:55     ` Jongsung Kim
2015-10-07  3:55       ` Jongsung Kim
2015-10-07  9:01       ` Russell King - ARM Linux
2015-10-07  9:01         ` Russell King - ARM Linux
2015-10-12  5:30         ` Jongsung Kim
2015-10-12  5:30           ` Jongsung Kim
2015-10-12  9:27           ` Arnd Bergmann
2015-10-12  9:27             ` Arnd Bergmann
2015-10-13  2:06             ` Jongsung Kim [this message]
2015-10-13  2:06               ` Jongsung Kim
2015-10-13 11:44               ` Arnd Bergmann
2015-10-13 11:44                 ` Arnd Bergmann
2015-10-12  6:00 ` yalin wang
2015-10-12  6:00   ` yalin wang

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