From mboxrd@z Thu Jan 1 00:00:00 1970 From: dirk.behme@googlemail.com (Dirk Behme) Date: Sun, 01 Apr 2012 10:50:14 +0200 Subject: Bug in v7_coherent_kern_range() ? In-Reply-To: <4F780EC8.1090303@freescale.com> References: <4F77C9A6.6080601@freescale.com> <4F77F13D.7000402@googlemail.com> <4F77FF24.5010809@freescale.com> <4F780B65.7020904@googlemail.com> <4F780EC8.1090303@freescale.com> Message-ID: <4F7816C6.8090904@googlemail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 01.04.2012 10:16, Huang Shijie wrote: > Hi Dirk: >> Hi Huang Shijie, >> >> On 01.04.2012 09:09, Huang Shijie wrote: >>> Hi Dirk: >>>> Hi Huang Shijie, >>>> >>>> On 01.04.2012 05:21, Huang Shijie wrote: >>>>> [1] Platform: >>>>> freescale's IMX6Q(4 cores) , ARM CORTEX-A9 >>>>> >>>>> [2] kernel: >>>>> 3.0.15(I have cherry-picked many patches, and the >>>>> arch/arm/mm/cache-v7.S >>>>> is same code with the latest kernel v3.4-rc1) >>>>> enable SMP, VIPT, >>>> >>>> Could you try an unpatched, clean v3.4-rc1 instead? >>> Sorry, I could not try the v3.4-rc1. Some our bsp drivers are not DT >>> supported. >> >> I think we are not talking about drivers, we are talking about some >> kernel core code, like cache handling? To test >> v7_coherent_kern_range() you might not need to many bsp drivers? > Yes , the gplay will use the vpu driver. But the VPU driver is not in > the kernel. Without the vpu driver, the gplay can not works. You could try to disable the vpu driver and check if the issue is still there, then. >>>> What's about your 2.6.38? >>> 2.6.38 is not a good version to run the imx6q. It losts many our >>> drivers's patches. >>>> >>>> What's about 3.0.26? 3.0.15 seems to miss some maybe relevant >>>> patches. >>>> >>> Our bsp release are based on 3.0.15. so we could not test it on 3.0.26 >>> too. >> >> You can. Just give git rebase a try. > It will be a nightmare to me. We have nearly 1000 patches. I will cost > me much time to handle the conflicts. IMHO you will get one easy to solve merge conflict. So it should you take < 10min to rebase to 3.0.26. Just try it ;) >> >>>>> [3] application: >>>> >>>> Could you share a (simple) test case? >>> The test case is like this: >>> #gplay xx.avi >>> >>> gplay is our own player, such as mplayer. >> >> Could you share a (simple) test case? E.g. share 'gplay'? Or try to >> reproduce your issue with an other test case? E.g. mplayer? Or >> better anything simpler the community can use to try to reproduce >> your issue? > I can email to you the gplay, if you have an imx6q board. you can test > it. > I just wish someone give me some advice about this issue. It would help to use a kernel version and a test case the community can use to reproduce. Best regards Dirk > I find the arch/arm/include/asm/assembler.h is out of date. So I will > update it and test it again. > > thanks a lot , Dirk. > > Huang Shijie >> >> Best regards >> >> Dirk >> >>> I just created a script which will play the video files one by one. >>> >>> BR >>> Huang Shijie >>> >>>> >>>> Best regards >>>> >>>> Dirk >>>> >>>>> I use our our application which will clone many threads, >>>>> two threads (assume as A and B) may do the same thing at the same >>>>> time >>>>> as the following code: >>>>> >>>>> In most of the time, it's ok. >>>>> But in some unknown situation, cacheflush() failed and one threads >>>>> (assume A) may hung up in the following code: >>>>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>>>> >>>>> >>>>> >>>>> open("/usr/lib/lib_mp3_dec_arm12_elinux.so.2.10.0", O_RDONLY) = 8 >>>>> read(8, >>>>> "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0\20\35\0\0004\0\0\0"..., >>>>> >>>>> >>>>> 512) = 512 >>>>> fstat64(8, {st_mode=S_IFREG|0644, st_size=56232, ...}) = 0 >>>>> mmap2(NULL, 88032, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, >>>>> 8, 0) >>>>> = 0x2ff0a000 >>>>> mprotect(0x2ff18000, 28672, PROT_NONE) = 0 >>>>> mmap2(0x2ff1f000, 4096, PROT_READ|PROT_WRITE, >>>>> MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 8, 0xd) = 0x2ff1f000 >>>>> close(8) = 0 >>>>> mprotect(0x2ff0a000, 57344, PROT_READ|PROT_WRITE) = 0 >>>>> mprotect(0x2ff0a000, 57344, PROT_READ|PROT_EXEC) = 0 >>>>> cacheflush(0x2ff0a000, 0x2ff18000, 0, 0x6, 0x2cd03420) = 0 // System >>>>> hung up here!!! >>>>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>>>> >>>>> >>>>> >>>>> >>>>> [4] kernel log >>>>> I use "echo t> /proc/sysrq-trigger" to show the tasks's information: >>>>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>>>> >>>>> >>>>> >>>>> multiqueue0:src D 804cd678 0 7328 5963 0x00000001 >>>>> [<804cd678>] (__schedule+0x228/0x760) from [<804d0564>] >>>>> (__down_read+0xa8/0xe0) >>>>> [<804d0564>] (__down_read+0xa8/0xe0) from [<800478c4>] >>>>> (do_page_fault+0xbc/0x480) >>>>> [<800478c4>] (do_page_fault+0xbc/0x480) from [<8003841c>] >>>>> (do_DataAbort+0x34/0x98) >>>>> [<8003841c>] (do_DataAbort+0x34/0x98) from [<8003df10>] >>>>> (__dabt_svc+0x70/0xa0) >>>>> Exception stack(0xbae37ea8 to 0xbae37ef0) >>>>> 7ea0: 31e05000 31e1d000 00000020 0000001f 31e05000 31e1d000 >>>>> 7ec0: bfac86b8 31e05000 31e1d000 bae36000 08100075 31e056fc 31e08000 >>>>> bae37ef0 >>>>> 7ee0: 800424a8 8004a1fc 800f0013 ffffffff >>>>> [<8003df10>] (__dabt_svc+0x70/0xa0) from [<8004a1fc>] >>>>> (v7_coherent_kern_range+0x20/0x80) >>>>> [<8004a1fc>] (v7_coherent_kern_range+0x20/0x80) from [<800424a8>] >>>>> (arm_syscall+0x2a0/0x2c4) >>>>> [<800424a8>] (arm_syscall+0x2a0/0x2c4) from [<8003e500>] >>>>> (ret_fast_syscall+0x0/0x3c) >>>>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>>>> >>>>> >>>>> >>>>> >>>>> The do_cache_op() has already held the mm->mmap_sem, but >>>>> v7_coherent_kern_range() >>>>> cause one page fault during it flush the cache. deadlock! So it >>>>> hung up >>>>> in the do_page_fault(). >>>>> >>>>> [5] questions: >>>>> Why the v7_coherent_kern_range() can caused the data abort? >>>>> Is there something wrong about the v7_coherent_kern_range()? >>>>> >>>>> >>>>> thanks >>>>> Huang Shijie >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> linux-arm-kernel mailing list >>>>> linux-arm-kernel at lists.infradead.org >>>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>>>> >>>> >>>> >>> >>> >>> >> >> > > >