From: Pavel Machek <pavel@ucw.cz>
To: Archit Taneja <architt@codeaurora.org>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Marek Vasut <marek.vasut@gmail.com>,
kernel list <linux-kernel@vger.kernel.org>,
Dinh Nguyen <dinh.linux@gmail.com>,
Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>,
Grant Likely <grant.likely@linaro.org>,
Rob Herring <robh+dt@kernel.org>,
Jingoo Han <jg1.han@samsung.com>, Rob Clark <robdclark@gmail.com>,
Linux Fbdev development list <linux-fbdev@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
shc_work@mail.ru, linux@arm.linux.org.uk,
hsweeten@visionengravers.com
Subject: Re: simple framebuffer slower by factor of 20, on socfpga (arm) platform
Date: Fri, 24 Apr 2015 13:29:23 +0000 [thread overview]
Message-ID: <20150424132923.GA11729@amd> (raw)
In-Reply-To: <55277650.8070607@codeaurora.org>
Hi!
On Fri 2015-04-10 12:35:52, Archit Taneja wrote:
> >That said, if the fb is in RAM, and is only written by the CPU, I think
> >a normal memcpy() for fb_memcpy_fromfb() should be fine...
>
> I didn't test for performance regressions when I posted this patch.
>
> A look at _memcpy_fromio in arch/arm/kernel/io.c shows that readb() is used
> all the time, even when the source and destination addresses are aligned for
> larger reads to be possible. Other archs seem to use readl() or readq() when
> they can. Maybe that makes memcpy_fromio slower than the implementation of
> memcpy on arm?
Ok, can you prepare a patch for me to try? Or should we just revert
the original commit?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2015-04-24 13:29 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-07 12:12 simple framebuffer slower by factor of 20, on socfpga (arm) platform Pavel Machek
2015-04-07 12:19 ` Geert Uytterhoeven
2015-04-07 14:24 ` Marek Vasut
2015-04-09 11:06 ` Pavel Machek
2015-04-09 11:21 ` Tomi Valkeinen
2015-04-09 11:34 ` Tomi Valkeinen
[not found] ` <552663C2.70308-l0cyMroinI0@public.gmane.org>
2015-04-09 19:51 ` Arnd Bergmann
2015-04-24 13:31 ` Pavel Machek
2015-04-10 7:17 ` Archit Taneja
2015-04-24 13:29 ` Pavel Machek [this message]
2015-04-24 13:40 ` Tomi Valkeinen
2015-04-24 13:46 ` Geert Uytterhoeven
2015-04-26 19:31 ` Pavel Machek
2015-04-28 13:48 ` Russell King - ARM Linux
[not found] ` <20150428134848.GC12732-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
2015-04-28 15:28 ` Nicolas Pitre
2015-05-06 10:45 ` Russell King - ARM Linux
2015-05-06 20:32 ` Nicolas Pitre
2015-05-12 8:52 ` Pavel Machek
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