From: Sam Ravnborg <sam@ravnborg.org>
To: Thomas Zimmermann <tzimmermann@suse.de>
Cc: daniel@ffwll.ch, deller@gmx.de, javierm@redhat.com,
geert@linux-m68k.org, kraxel@redhat.com, ppaalanen@gmail.com,
dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org
Subject: Re: [PATCH v3 4/5] fbdev: Improve performance of cfb_imageblit()
Date: Wed, 23 Feb 2022 21:25:45 +0100 [thread overview]
Message-ID: <YhaYSeyYIwqur2hy@ravnborg.org> (raw)
In-Reply-To: <20220223193804.18636-5-tzimmermann@suse.de>
On Wed, Feb 23, 2022 at 08:38:03PM +0100, Thomas Zimmermann wrote:
> Improve the performance of cfb_imageblit() by manually unrolling
> the inner blitting loop and moving some invariants out. The compiler
> failed to do this automatically. This change keeps cfb_imageblit()
> in sync with sys_imagebit().
>
> A microbenchmark measures the average number of CPU cycles
> for cfb_imageblit() after a stabilizing period of a few minutes
> (i7-4790, FullHD, simpledrm, kernel with debugging).
>
> cfb_imageblit(), new: 15724 cycles
> cfb_imageblit(): old: 30566 cycles
>
> In the optimized case, cfb_imageblit() is now ~2x faster than before.
>
> v3:
> * fix commit description (Pekka)
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
The code looks equally complicated now in the sys and cfb variants.
Question: What is cfb an abbreviation for anyway?
Not related to the patch - but if I have known the memory is lost..
Sam
WARNING: multiple messages have this Message-ID (diff)
From: Sam Ravnborg <sam@ravnborg.org>
To: Thomas Zimmermann <tzimmermann@suse.de>
Cc: linux-fbdev@vger.kernel.org, deller@gmx.de, javierm@redhat.com,
dri-devel@lists.freedesktop.org, geert@linux-m68k.org,
kraxel@redhat.com
Subject: Re: [PATCH v3 4/5] fbdev: Improve performance of cfb_imageblit()
Date: Wed, 23 Feb 2022 21:25:45 +0100 [thread overview]
Message-ID: <YhaYSeyYIwqur2hy@ravnborg.org> (raw)
In-Reply-To: <20220223193804.18636-5-tzimmermann@suse.de>
On Wed, Feb 23, 2022 at 08:38:03PM +0100, Thomas Zimmermann wrote:
> Improve the performance of cfb_imageblit() by manually unrolling
> the inner blitting loop and moving some invariants out. The compiler
> failed to do this automatically. This change keeps cfb_imageblit()
> in sync with sys_imagebit().
>
> A microbenchmark measures the average number of CPU cycles
> for cfb_imageblit() after a stabilizing period of a few minutes
> (i7-4790, FullHD, simpledrm, kernel with debugging).
>
> cfb_imageblit(), new: 15724 cycles
> cfb_imageblit(): old: 30566 cycles
>
> In the optimized case, cfb_imageblit() is now ~2x faster than before.
>
> v3:
> * fix commit description (Pekka)
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
The code looks equally complicated now in the sys and cfb variants.
Question: What is cfb an abbreviation for anyway?
Not related to the patch - but if I have known the memory is lost..
Sam
next prev parent reply other threads:[~2022-02-23 20:25 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-23 19:37 [PATCH v3 0/5] fbdev: Improve performance of fbdev console Thomas Zimmermann
2022-02-23 19:37 ` Thomas Zimmermann
2022-02-23 19:38 ` [PATCH v3 1/5] fbdev: Improve performance of sys_fillrect() Thomas Zimmermann
2022-02-23 19:38 ` Thomas Zimmermann
2022-02-23 19:38 ` [PATCH v3 2/5] fbdev: Improve performance of sys_imageblit() Thomas Zimmermann
2022-02-23 19:38 ` Thomas Zimmermann
2022-02-23 19:38 ` [PATCH v3 3/5] fbdev: Remove trailing whitespaces from cfbimgblt.c Thomas Zimmermann
2022-02-23 19:38 ` Thomas Zimmermann
2022-02-23 20:23 ` Sam Ravnborg
2022-02-23 20:23 ` Sam Ravnborg
2022-02-24 8:22 ` Javier Martinez Canillas
2022-02-24 8:22 ` Javier Martinez Canillas
2022-02-23 19:38 ` [PATCH v3 4/5] fbdev: Improve performance of cfb_imageblit() Thomas Zimmermann
2022-02-23 19:38 ` Thomas Zimmermann
2022-02-23 20:25 ` Sam Ravnborg [this message]
2022-02-23 20:25 ` Sam Ravnborg
2022-02-24 9:02 ` Javier Martinez Canillas
2022-02-24 9:02 ` Javier Martinez Canillas
2022-02-24 10:29 ` Sam Ravnborg
2022-02-24 10:29 ` Sam Ravnborg
2022-02-24 10:31 ` Geert Uytterhoeven
2022-02-24 10:31 ` Geert Uytterhoeven
2022-02-24 8:31 ` Javier Martinez Canillas
2022-02-24 8:31 ` Javier Martinez Canillas
2022-03-08 22:52 ` [v3,4/5] " Marek Szyprowski
2022-03-09 8:22 ` Thomas Zimmermann
2022-03-09 9:22 ` Marek Szyprowski
2022-03-09 10:39 ` Geert Uytterhoeven
2022-03-09 10:39 ` Geert Uytterhoeven
2022-03-10 19:21 ` Thomas Zimmermann
2022-03-10 19:21 ` Thomas Zimmermann
2022-03-10 19:23 ` Geert Uytterhoeven
2022-03-10 19:23 ` Geert Uytterhoeven
2022-03-13 19:23 ` Thomas Zimmermann
2022-03-13 19:23 ` Thomas Zimmermann
2022-03-24 19:11 ` [PATCH v3 4/5] " Guenter Roeck
2022-03-24 19:11 ` Guenter Roeck
2022-03-24 19:18 ` Thomas Zimmermann
2022-03-24 19:18 ` Thomas Zimmermann
2022-03-24 21:18 ` Guenter Roeck
2022-03-24 21:18 ` Guenter Roeck
2022-02-23 19:38 ` [PATCH v3 5/5] drm: Add TODO item for optimizing format helpers Thomas Zimmermann
2022-02-23 19:38 ` Thomas Zimmermann
2022-02-23 20:34 ` Sam Ravnborg
2022-02-23 20:34 ` Sam Ravnborg
2022-02-24 8:39 ` Javier Martinez Canillas
2022-02-24 8:39 ` Javier Martinez Canillas
2022-03-02 19:30 ` [PATCH v3 0/5] fbdev: Improve performance of fbdev console Thomas Zimmermann
2022-03-02 19:30 ` Thomas Zimmermann
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