From mboxrd@z Thu Jan 1 00:00:00 1970 From: Khem Raj Date: Thu, 4 Aug 2016 19:09:44 -0700 Subject: [Buildroot] Raspberry Pi OpenGL/Qt5 10x slower than Raspbian In-Reply-To: References: <20160804091707.6755bb66@free-electrons.com> <20160804182825.4c9ff4ff@free-electrons.com> Message-ID: <6fc2fbb9-e4ff-6aeb-692d-5893d2f9ec9f@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net On 8/4/16 10:09 AM, Frank Hunleth wrote: > Hi Thomas, > > On Thu, Aug 4, 2016 at 12:28 PM, Thomas Petazzoni > wrote: >> Hello, >> >> On Thu, 4 Aug 2016 08:35:24 -0400, Frank Hunleth wrote: >> >>>> Change -Os by -O2 in the Buildroot configuration, by using >>>> BR2_OPTIMIZE_2. I even believe we should stop using BR2_OPTIMIZE_S by >>>> default, and switch to BR2_OPTIMIZE_2 instead. >>> >>> Done, but no luck for this particular issue. I have another piece of >>> code that differs in performance from Debian by 5% and is more CPU >>> bound. I'll try it on that too. >> >> Gaah. >> >>>> Also, are you sure it's really using OpenGL with the Buildroot build? >>> >>> On the Buildroot build, I've tried running the Qt application with >>> "-platform eglfs", but that seemed to be the default already. I'm not >>> sure how to check deeper than that. >> >> I guess if eglfs support has been built and you're able to use, it >> means that it's using the GPU. >> >>>> Under Raspbian, are you also running the eglfs build of Qt, or is it >>>> with X.org? I'm not sure Debian has an eglfs capable build of Qt5. >>> >>> You're right. On Raspbian, I'm running with X.org. I am naively >>> assuming that Qt5 w/ eglfs isn't 10x slower than Qt5 w/ X.org. I >>> really hope that's not the case. >> >> I also hope, but using X.org on one side and doing eglfs on the other >> side is really a very different configuration. I would also assume that >> there should not be a 10x difference between Qt5/X.org vs Qt5/eglfs, >> but I have never tested, so I don't know. > > I started a Qt5/eglfs-only build on a Raspberry Pi early this morning. > I have no clue how long it will take to build, but I'll report back > when it's done. > >> Which toolchain are you using ? Are you building everything optimized >> for ARMv6 (assuming you're using Rpi1) ? > > When I first noticed the issue, I was using an ARMv6-optimized > toolchain built by crosstool-ng. Now I'm using the default one built > by Buildroot when using the raspberrypi_defconfig. > >> But a 10x difference really feels like acceleration is not used at all. > > I agree. > >> You can also check the CPU consumption while running your Qt app to see >> what it looks like. > > Will do. I think that the native Raspbian Qt5/eglfs-only build will be > telling. With any luck the build will complete successfully this > evening. Seems like H/W acceleration is missing. I wonder if userland libraries are compiled correctly. > > Thanks, > Frank > _______________________________________________ > buildroot mailing list > buildroot at busybox.net > http://lists.busybox.net/mailman/listinfo/buildroot >