From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM:mm: fix kmap_atomic_to_page
Date: Mon, 12 Oct 2015 11:27:42 +0200 [thread overview]
Message-ID: <5778996.I0Vmityi0g@wuerfel> (raw)
In-Reply-To: <561B457F.5090104@lge.com>
On Monday 12 October 2015 14:30:39 Jongsung Kim wrote:
> We tried to utilize a HW compressor as a zram backend. Current zram uses
> kmap_atomic to map a page, and the HW DMAes. So we needed to use
> kmap_atomic_to_page to get the page to be dma-mapped.
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
next prev parent reply other threads:[~2015-10-12 9:27 UTC|newest]
Thread overview: 10+ 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 19:28 ` Russell King - ARM Linux
2015-10-07 1:37 ` Nicolas Pitre
2015-10-07 3:55 ` Jongsung Kim
2015-10-07 9:01 ` Russell King - ARM Linux
2015-10-12 5:30 ` Jongsung Kim
2015-10-12 9:27 ` Arnd Bergmann [this message]
2015-10-13 2:06 ` Jongsung Kim
2015-10-13 11:44 ` Arnd Bergmann
2015-10-12 6:00 ` yalin wang
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