From: Arnd Bergmann <arnd@arndb.de>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>,
"Heiko Stübner" <heiko@sntech.de>,
"Padmavathi Venna" <padma.v@samsung.com>,
"Takashi Iwai" <tiwai@suse.de>,
"Alessandro Rubini" <rubini@gnudd.com>,
"Tomasz Figa" <tomasz.figa@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Giancarlo Asnaghi" <giancarlo.asnaghi@st.com>,
linux-samsung-soc <linux-samsung-soc@vger.kernel.org>,
"Russell King - ARM Linux" <linux@arm.linux.org.uk>,
"Vinod Koul" <vinod.koul@intel.com>,
"Thomas Abraham" <thomas.abraham@linaro.org>,
"Grant Likely" <grant.likely@linaro.org>,
"Kukjin Kim" <kgene.kim@samsung.com>,
"Sylwester Nawrocki" <sylvester.nawrocki@gmail.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"Sangbeom Kim" <sbkim73@samsung.com>,
"Liam Girdwood" <lgirdwood@gmail.com>,
linux-spi@vger.kernel.org, "Mark Brown" <broonie@kerne>
Subject: Re: [RFC PATCH 01/11] dma: amba-pl08x: Use bitmap to pass variant specific quirks
Date: Tue, 18 Jun 2013 15:33:46 +0200 [thread overview]
Message-ID: <201306181533.46905.arnd@arndb.de> (raw)
In-Reply-To: <CACRpkdbt4fAdnDKuP8bVpwrWoJ-oGNuSbiDZDz5J12ix2qijfQ@mail.gmail.com>
On Tuesday 18 June 2013, Linus Walleij wrote:
> I thought about it yesterday and it basically looks to me that
> it tries to outsmart the compiler on how to stuff the flags to save
> struct space on the heap and hint that they can be determined
> quickly by a & operation, this is like premature optimization.
>
> So please go back to the old system.
Note that a 'bool' is typically stored as a 32-bit field, so there
would be some space saving if there are a lot of flags.
I agree with the conclusion though, the previous state was more
readable, which outweighs any benefits.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 01/11] dma: amba-pl08x: Use bitmap to pass variant specific quirks
Date: Tue, 18 Jun 2013 15:33:46 +0200 [thread overview]
Message-ID: <201306181533.46905.arnd@arndb.de> (raw)
In-Reply-To: <CACRpkdbt4fAdnDKuP8bVpwrWoJ-oGNuSbiDZDz5J12ix2qijfQ@mail.gmail.com>
On Tuesday 18 June 2013, Linus Walleij wrote:
> I thought about it yesterday and it basically looks to me that
> it tries to outsmart the compiler on how to stuff the flags to save
> struct space on the heap and hint that they can be determined
> quickly by a & operation, this is like premature optimization.
>
> So please go back to the old system.
Note that a 'bool' is typically stored as a 32-bit field, so there
would be some space saving if there are a lot of flags.
I agree with the conclusion though, the previous state was more
readable, which outweighs any benefits.
Arnd
next prev parent reply other threads:[~2013-06-18 13:33 UTC|newest]
Thread overview: 133+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-16 20:54 [RFC PATCH 00/11] ARM: s3c64xx: Let amba-pl08x driver handle DMA Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` [RFC PATCH 01/11] dma: amba-pl08x: Use bitmap to pass variant specific quirks Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 13:25 ` Linus Walleij
2013-06-17 13:25 ` Linus Walleij
2013-06-17 18:48 ` Russell King - ARM Linux
2013-06-17 18:48 ` Russell King - ARM Linux
2013-06-17 18:48 ` Russell King - ARM Linux
2013-06-17 18:56 ` Tomasz Figa
2013-06-17 18:56 ` Tomasz Figa
2013-06-17 18:56 ` Tomasz Figa
2013-06-18 7:47 ` Linus Walleij
2013-06-18 7:47 ` Linus Walleij
2013-06-18 13:33 ` Arnd Bergmann [this message]
2013-06-18 13:33 ` Arnd Bergmann
2013-06-16 20:54 ` [RFC PATCH 02/11] dma: amba-pl08x: Refactor pl08x_getbytes_chan() to lower indentation Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 13:29 ` Linus Walleij
2013-06-17 13:29 ` Linus Walleij
2013-06-16 20:54 ` [RFC PATCH 03/11] dma: amba-pl08x: Add support for different offset of CONFIG register Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 13:31 ` Linus Walleij
2013-06-17 13:31 ` Linus Walleij
2013-06-17 18:52 ` Russell King - ARM Linux
2013-06-17 18:52 ` Russell King - ARM Linux
2013-06-17 18:52 ` Russell King - ARM Linux
2013-06-17 19:02 ` Tomasz Figa
2013-06-17 19:02 ` Tomasz Figa
2013-06-17 19:02 ` Tomasz Figa
2013-06-16 20:54 ` [RFC PATCH 04/11] dma: amba-pl08x: Add support for PL080S variant Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 13:39 ` Linus Walleij
2013-06-17 13:39 ` Linus Walleij
2013-06-17 18:22 ` Tomasz Figa
2013-06-17 18:22 ` Tomasz Figa
2013-06-16 20:54 ` [RFC PATCH 05/11] dma: amba-pl08x: Add support for different maximum transfer size Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 13:42 ` Linus Walleij
2013-06-17 13:42 ` Linus Walleij
2013-06-17 18:27 ` Tomasz Figa
2013-06-17 18:27 ` Tomasz Figa
2013-06-16 20:54 ` [RFC PATCH 06/11] dma: amba-pl08x: Keep LLIs aligned to 4-word boundary Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 13:51 ` Linus Walleij
2013-06-17 13:51 ` Linus Walleij
2013-06-17 18:28 ` Tomasz Figa
2013-06-17 18:28 ` Tomasz Figa
2013-06-17 19:01 ` Russell King - ARM Linux
2013-06-17 19:01 ` Russell King - ARM Linux
2013-06-16 20:54 ` [RFC PATCH 07/11] dmaengine: PL08x: Fix reading the byte count in cctl Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 13:53 ` Linus Walleij
2013-06-17 13:53 ` Linus Walleij
2013-06-17 18:32 ` Tomasz Figa
2013-06-17 18:32 ` Tomasz Figa
2013-06-17 19:03 ` Russell King - ARM Linux
2013-06-17 19:03 ` Russell King - ARM Linux
2013-06-16 20:54 ` [RFC PATCH 08/11] dmaengine: PL08x: Add cyclic transfer support Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 13:57 ` Linus Walleij
2013-06-17 13:57 ` Linus Walleij
2013-06-17 18:52 ` Tomasz Figa
2013-06-17 18:52 ` Tomasz Figa
2013-06-17 18:56 ` Russell King - ARM Linux
2013-06-17 18:56 ` Russell King - ARM Linux
2013-06-17 18:56 ` Russell King - ARM Linux
2013-06-16 20:54 ` [RFC PATCH 09/11] spi: s3c64xx: Do not require legacy DMA API in case of S3C64XX Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 13:59 ` Linus Walleij
2013-06-17 13:59 ` Linus Walleij
2013-06-17 16:06 ` Mark Brown
2013-06-17 16:06 ` Mark Brown
2013-06-17 19:36 ` Tomasz Figa
2013-06-17 19:36 ` Tomasz Figa
2013-06-16 20:54 ` [RFC PATCH 10/11] ASoC: samsung: " Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 14:01 ` Linus Walleij
2013-06-17 14:01 ` Linus Walleij
2013-06-16 20:54 ` [RFC PATCH 11/11] ARM: s3c64xx: Add support for DMA using generic amba-pl08x driver Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-16 20:54 ` Tomasz Figa
2013-06-17 14:04 ` Linus Walleij
2013-06-17 14:04 ` Linus Walleij
2013-06-19 18:23 ` Tomasz Figa
2013-06-19 18:23 ` Tomasz Figa
2013-06-19 19:50 ` Linus Walleij
2013-06-19 19:50 ` Linus Walleij
2013-06-17 14:06 ` [RFC PATCH 00/11] ARM: s3c64xx: Let amba-pl08x driver handle DMA Linus Walleij
2013-06-17 14:06 ` Linus Walleij
2013-06-17 19:38 ` Tomasz Figa
2013-06-17 19:38 ` Tomasz Figa
2013-06-19 17:40 ` Mark Brown
2013-06-19 17:40 ` Mark Brown
2013-06-19 17:40 ` Mark Brown
2013-06-19 18:26 ` Tomasz Figa
2013-06-19 18:26 ` Tomasz Figa
2013-06-19 18:26 ` Tomasz Figa
2013-06-19 19:01 ` Arnd Bergmann
2013-06-19 19:01 ` Arnd Bergmann
2013-06-19 19:01 ` Arnd Bergmann
2013-06-19 19:24 ` Mark Brown
2013-06-19 19:24 ` Mark Brown
2013-06-19 19:24 ` Mark Brown
2013-06-19 19:22 ` Mark Brown
2013-06-19 19:22 ` Mark Brown
2013-06-19 19:22 ` Mark Brown
2013-06-19 19:32 ` Tomasz Figa
2013-06-19 19:32 ` Tomasz Figa
2013-06-19 19:32 ` Tomasz Figa
2013-06-19 22:48 ` Mark Brown
2013-06-19 22:48 ` Mark Brown
2013-06-19 22:48 ` Mark Brown
2013-06-20 9:24 ` Phil Carmody
2013-06-20 9:24 ` Phil Carmody
2013-06-20 10:35 ` Mark Brown
2013-06-20 10:35 ` Mark Brown
2013-06-20 11:14 ` Phil Carmody
2013-06-20 11:14 ` Phil Carmody
2013-06-21 9:47 ` Mark Brown
2013-06-21 9:47 ` Mark Brown
2013-06-21 9:47 ` Mark Brown
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=201306181533.46905.arnd@arndb.de \
--to=arnd@arndb.de \
--cc=alsa-devel@alsa-project.org \
--cc=broonie@kerne \
--cc=giancarlo.asnaghi@st.com \
--cc=grant.likely@linaro.org \
--cc=heiko@sntech.de \
--cc=kgene.kim@samsung.com \
--cc=lgirdwood@gmail.com \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=padma.v@samsung.com \
--cc=rubini@gnudd.com \
--cc=sbkim73@samsung.com \
--cc=sylvester.nawrocki@gmail.com \
--cc=thomas.abraham@linaro.org \
--cc=tiwai@suse.de \
--cc=tomasz.figa@gmail.com \
--cc=vinod.koul@intel.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.