From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id mA33OeFu028880 for ; Sun, 2 Nov 2008 22:24:40 -0500 Received: from QMTA09.westchester.pa.mail.comcast.net (qmta09.westchester.pa.mail.comcast.net [76.96.62.96]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id mA33NlwD001653 for ; Sun, 2 Nov 2008 22:23:47 -0500 Message-ID: <490E6EC3.7030408@personnelware.com> Date: Sun, 02 Nov 2008 21:23:47 -0600 From: Carl Karsten MIME-Version: 1.0 To: Andy Walls References: <47C90994.8040304@personnelware.com> <20080304113834.0140884d@gaivota> <490E468A.6090200@personnelware.com> <1225675203.3116.12.camel@palomino.walls.org> In-Reply-To: <1225675203.3116.12.camel@palomino.walls.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: video4linux-list@redhat.com, Mauro Carvalho Chehab Subject: Re: v4l2 api compliance test List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: video4linux-list-bounces@redhat.com Errors-To: video4linux-list-bounces@redhat.com List-ID: Andy Walls wrote: > On Sun, 2008-11-02 at 18:32 -0600, Carl Karsten wrote: >> Mauro Carvalho Chehab wrote: >>> On Sat, 01 Mar 2008 01:45:24 -0600 >>> Carl Karsten wrote: >>> >>> >>> Please, feel free to improve the tools. Unfortunately, nobody yet had time to >>> dedicate on improving the testing tools. >> These 2 issues are thwarting my efforts to write my tester: >> >> 1. memory leak: >> valgrind ./capture --userp -d /dev/video1 >> ==17153== malloc/free: in use at exit: 2,457,632 bytes in 5 blocks. >> >> 2. capabilities mismatch: >> ./capture --userp -d /dev/video1 >> VIDIOC_QBUF error 22, Invalid argument >> >> details: http://linuxtv.org/v4lwiki/index.php/Test_Suite#Bugs_in_Examples > > I'm not sure why a memory leak on abnormal termination is worrisome for > you. It looks like init_userp() allocated a bunch of "buffers", which > has to happen for a program to use user pointer mode of v4l2. The > function errno_exit() doesn't bother to clean up when the VIDIOC_QBUF > ioctl() call fails. free() is only called by uninit_device(). Since > the alternate flow of the program through errno_exit() to termination > doesn't call free() on "buffers", you should have a process heap memory > leak on error exit. > > Since this is userspace, a memory leak from the process heap doesn't > hang around when the process terminates - no big deal. Are you sure about that? if I run ./capture --userp -d /dev/video1 VIDIOC_QBUF error 22, Invalid argument enough I can't run the valid modes: juser@dhcp186:~/vga2usb/v4l.org/examples$ ./capture --read -d /dev/video1 read error 12, Cannot allocate memory juser@dhcp186:~/vga2usb/v4l.org/examples$ ./capture --mmap -d /dev/video1 mmap error 12, Cannot allocate memory although free still shows lots: juser@dhcp186:~/vga2usb/v4l.org/examples$ free total used free shared buffers cached Mem: 1033388 282340 751048 0 31012 98208 -/+ buffers/cache: 153120 880268 Swap: 859436 0 859436 > You could > equally gripe that the program didn't close it's file descriptors with > the driver on errno_exit() - but process termination cleans those up > too. I am personally interested in anything that makes it harder for me to determine if a driver is misbehaving. In addition, I would think that the API's example code should be a squeaky clean example of how real code should be written, given it is often used as a starting point. If problems are identified, they should at least be noted, better yet removed. Carl K -- video4linux-list mailing list Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe https://www.redhat.com/mailman/listinfo/video4linux-list