From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann 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 Message-ID: <201306181533.46905.arnd@arndb.de> References: <1371416058-22047-1-git-send-email-tomasz.figa@gmail.com> <12368941.dQe8bcScGj@flatron> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.17.9]) by alsa0.perex.cz (Postfix) with ESMTP id 8B6FE2650C3 for ; Tue, 18 Jun 2013 15:33:55 +0200 (CEST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Linus Walleij Cc: "alsa-devel@alsa-project.org" , Heiko =?iso-8859-1?q?St=FCbner?= , Padmavathi Venna , Takashi Iwai , Alessandro Rubini , Tomasz Figa , "linux-kernel@vger.kernel.org" , Giancarlo Asnaghi , linux-samsung-soc , Russell King - ARM Linux , Vinod Koul , Thomas Abraham , Grant Likely , Kukjin Kim , Sylwester Nawrocki , "linux-arm-kernel@lists.infradead.org" , Sangbeom Kim , Liam Girdwood , linux-spi@vger.kernel.org, Mark Brown List-Id: alsa-devel@alsa-project.org 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Tue, 18 Jun 2013 15:33:46 +0200 Subject: [RFC PATCH 01/11] dma: amba-pl08x: Use bitmap to pass variant specific quirks In-Reply-To: References: <1371416058-22047-1-git-send-email-tomasz.figa@gmail.com> <12368941.dQe8bcScGj@flatron> Message-ID: <201306181533.46905.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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