Em Wed, 27 Apr 2016 07:51:08 -0600 Shuah Khan <shuahkh@xxxxxxxxxxxxxxx> escreveu: > > - cdev patch; > > - kref patch. > > > > As a bonus side, by breaking into that, it helps to identify what > > fixes are needed if we found similar issues at the other parts of > > the subsystems. > > No problem breaking the it into 3 patches. I think the order should > be kref and the a patch to set cdev kobj parent. Is that what you > had in mind? Works for me. > > > > > If I remember well, I ended by having some cdev troubles with the > > V4L2 core on one of my stress test. So, this is something that > > we want to double check at RC, DVB and V4L parts that handle > > cdev, and eventually porting the changes to the core of those > > subsystems. > > Is that when you were playing with allocating cdev as opposed to > setting parent. btw. just setting parent isn't enough. Kobject > is necessary as it can then invoke the kobject put handler from > cdev-core. V4L2 has kref, as far as I remember, but not sure if it is doing the right thing. As I pointed on the previous e-mail, I'm getting some cdev issues that seem to be related to V4L2, like this: [ 1002.856150] general protection fault: 0000 [#5] SMP KASAN [ 1002.859995] Modules linked in: ir_lirc_codec lirc_dev au8522_dig xc5000 tuner au8522_decoder au8522_common au0828 videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core tveeprom dvb_core rc_core v4l2_common videodev media cpufreq_powersave cpufreq_conservative cpufreq_userspace cpufreq_stats parport_pc ppdev lp parport snd_hda_codec_hdmi intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm iTCO_wdt iTCO_vendor_support irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel i915 snd_hda_codec_realtek snd_hda_codec_generic sha256_ssse3 sha256_generic hmac drbg btusb btrtl btbcm aesni_intel evdev snd_hda_intel aes_x86_64 lrw btintel i2c_algo_bit snd_hda_codec gf128mul bluetooth glue_helper drm_kms_helper snd_hwdep ablk_helper cryptd snd_hda_core drm serio_raw [ 1002.870406] rfkill sg snd_pcm pcspkr snd_timer mei_me snd mei lpc_ich i2c_i801 mfd_core soundcore battery dw_dmac video dw_dmac_core i2c_designware_platform i2c_designware_core acpi_pad button tpm_tis tpm ext4 crc16 jbd2 mbcache dm_mod sd_mod ahci libahci psmouse libata e1000e ehci_pci xhci_pci ptp scsi_mod ehci_hcd pps_core xhci_hcd fan thermal sdhci_acpi sdhci mmc_core i2c_hid hid [ 1002.874971] CPU: 2 PID: 3640 Comm: v4l_id Tainted: G D 4.6.0-rc2+ #68 [ 1002.877246] Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0350.2015.0812.1722 08/12/2015 [ 1002.879650] task: ffff88009c273000 ti: ffff880035c70000 task.ti: ffff880035c70000 [ 1002.882891] RIP: 0010:[<ffffffff81d77a61>] [<ffffffff81d77a61>] usb_ifnum_to_if+0x31/0x270 [ 1002.886337] RSP: 0018:ffff880035c778d0 EFLAGS: 00010282 [ 1002.889950] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff1001364fc5e [ 1002.892009] RDX: 000000000000009e RSI: 0000000000000000 RDI: 00000000000004f0 [ 1002.893996] RBP: ffff880035c77908 R08: 0000000000000001 R09: 0000000000000001 [ 1002.895895] R10: ffff8803a239abf0 R11: 0000000000000000 R12: ffffffffa12be0c0 [ 1002.898465] R13: ffff88009b27eb3c R14: ffff88009b27c080 R15: ffffffffa12a89b0 [ 1002.902048] FS: 00007f0312a7e700(0000) GS:ffff8803c6900000(0000) knlGS:0000000000000000 [ 1002.905584] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1002.908676] CR2: 0000000001c84db0 CR3: 00000003a1cd8000 CR4: 00000000003406e0 [ 1002.910528] Stack: [ 1002.912378] ffff8803bf048000 ffff88009b27e2f0 ffff88009b27c000 ffffffffa12be0c0 [ 1002.915578] ffff88009b27eb3c ffff88009b27c080 ffffffffa12a89b0 ffff880035c77940 [ 1002.919242] ffffffffa12a4a45 ffff880035c77940 ffff88009b27c000 0000000000000000 [ 1002.921590] Call Trace: [ 1002.923451] [<ffffffffa12a89b0>] ? au0828_v4l2_close+0x5a0/0x5a0 [au0828] [ 1002.925339] [<ffffffffa12a4a45>] au0828_analog_stream_enable+0x85/0x330 [au0828] [ 1002.927234] [<ffffffffa12a8b11>] au0828_v4l2_open+0x161/0x350 [au0828] [ 1002.930247] [<ffffffffa12a89b0>] ? au0828_v4l2_close+0x5a0/0x5a0 [au0828] [ 1002.932695] [<ffffffffa1169561>] v4l2_open+0x1d1/0x350 [videodev] [ 1002.934556] [<ffffffff815cc071>] chrdev_open+0x1f1/0x580 [ 1002.936446] [<ffffffff815cbe80>] ? cdev_put+0x50/0x50 [ 1002.938301] [<ffffffff815b98a7>] do_dentry_open+0x5d7/0xac0 [ 1002.941460] [<ffffffff815cbe80>] ? cdev_put+0x50/0x50 [ 1002.943705] [<ffffffff815bc05b>] vfs_open+0x16b/0x1e0 [ 1002.945529] [<ffffffff815e1c0b>] ? may_open+0x14b/0x260 [ 1002.947334] [<ffffffff815eb3f7>] path_openat+0x4f7/0x3a00 [ 1002.949259] [<ffffffff8156cc95>] ? alloc_debug_processing+0x75/0x1c0 [ 1002.951185] [<ffffffff815eaf00>] ? vfs_create+0x390/0x390 [ 1002.953004] [<ffffffff811ad88e>] ? __kernel_text_address+0x7e/0xa0 [ 1002.954820] [<ffffffff8109154f>] ? print_context_stack+0x7f/0xf0 [ 1002.956646] [<ffffffff8124b110>] ? debug_check_no_locks_freed+0x290/0x290 [ 1002.959007] [<ffffffff815b105b>] ? create_object+0x3eb/0x940 [ 1002.962537] [<ffffffff8124a5f6>] ? trace_hardirqs_on_caller+0x16/0x590 [ 1002.966090] [<ffffffff815f1cd5>] do_filp_open+0x175/0x230 [ 1002.969603] [<ffffffff815f1b60>] ? user_path_mountpoint_at+0x40/0x40 [ 1002.973088] [<ffffffff822d8567>] ? _raw_spin_unlock+0x27/0x40 [ 1002.974921] [<ffffffff81615b1a>] ? __alloc_fd+0x19a/0x4b0 [ 1002.976759] [<ffffffff8156d653>] ? kmem_cache_alloc+0x233/0x300 [ 1002.978808] [<ffffffff815bc615>] do_sys_open+0x195/0x340 [ 1002.982167] [<ffffffff8123eb5f>] ? up_read+0x1f/0x40 [ 1002.983986] [<ffffffff815bc480>] ? filp_open+0x60/0x60 [ 1002.985810] [<ffffffff81242681>] ? trace_hardirqs_off_caller+0x21/0x290 [ 1002.987630] [<ffffffff8100401b>] ? trace_hardirqs_on_thunk+0x1b/0x1d [ 1002.989456] [<ffffffff815bc7de>] SyS_open+0x1e/0x20 [ 1002.991271] [<ffffffff822d8dc0>] entry_SYSCALL_64_fastpath+0x23/0xc1 [ 1002.993950] [<ffffffff81242681>] ? trace_hardirqs_off_caller+0x21/0x290 [ 1002.997492] Code: 48 b8 00 00 00 00 00 fc ff df 48 89 e5 41 57 41 56 41 55 41 54 53 48 89 fb 48 81 c7 f0 04 00 00 48 89 fa 48 c1 ea 03 48 83 ec 10 <80> 3c 02 00 0f 85 c6 01 00 00 4c 8b bb f0 04 00 00 4d 85 ff 0f [ 1003.000679] RIP [<ffffffff81d77a61>] usb_ifnum_to_if+0x31/0x270 [ 1003.002620] RSP <ffff880035c778d0> [ 1003.019559] ---[ end trace 9127ab975e0f4107 ]--- -- Thanks, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
