Peter Zijlstra <pet...@infradead.org> writes: > Alex, any clue?
Let me look into it. Definitely haven't seen anything like that in my tests. > On Fri, Jun 12, 2015 at 02:42:36PM -0400, Vince Weaver wrote: >> On Thu, 11 Jun 2015, Vince Weaver wrote: >> >> > and while I was trying to cut and paste that, the locked haswell just took >> > down the network switch so I can't get the rest until tomorrow. >> >> here are the full dumps if anyone is interested >> >> the warning is reproducible, the spinlock disaster is not. >> >> [36298.986117] BUG: spinlock recursion on CPU#4, perf_fuzzer/3410 >> [36298.992915] lock: 0xffff88011edf7cd0, .magic: dead4ead, .owner: >> perf_fuzzer/3410, .owner_cpu: 4 >> [36299.002919] CPU: 4 PID: 3410 Comm: perf_fuzzer Tainted: G W >> 4.1.0-rc7+ #155 >> [36299.012152] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS FBKT72AUS >> 01/26/2014 >> [36299.020606] ffff88011edf7cd0 ffff88011eb059a0 ffffffff816d7229 >> 0000000000000054 >> [36299.029199] ffff8800c2f4ac50 ffff88011eb059c0 ffffffff810c2895 >> ffff88011edf7cd0 >> [36299.037796] ffffffff81a1e481 ffff88011eb059e0 ffffffff810c2916 >> ffff88011edf7cd0 >> [36299.046338] Call Trace: >> [36299.049501] <NMI> [<ffffffff816d7229>] dump_stack+0x45/0x57 >> [36299.056284] [<ffffffff810c2895>] spin_dump+0x85/0xe0 >> [36299.062282] [<ffffffff810c2916>] spin_bug+0x26/0x30 >> [36299.068111] [<ffffffff810c2acf>] do_raw_spin_lock+0x13f/0x180 >> [36299.074897] [<ffffffff816de6e9>] _raw_spin_lock+0x39/0x40 >> [36299.081276] [<ffffffff8117a039>] ? free_pcppages_bulk+0x39/0x620 >> [36299.088340] [<ffffffff8117a039>] free_pcppages_bulk+0x39/0x620 >> [36299.095182] [<ffffffff81177e14>] ? free_pages_prepare+0x3a4/0x550 >> [36299.102291] [<ffffffff811c9936>] ? kfree_debugcheck+0x16/0x40 >> [36299.108987] [<ffffffff8117a938>] free_hot_cold_page+0x178/0x1a0 >> [36299.115850] [<ffffffff8117aa47>] __free_pages+0x37/0x50 >> [36299.121991] [<ffffffff8116ae0a>] rb_free_aux+0xba/0xf0 This one goes to free aux pages from nmi context, looks like aux buffer was unmapped while the event was running, so here it dropped the last reference. >> [36299.128034] [<ffffffff8116b0e7>] perf_aux_output_end+0xb7/0xf0 >> [36299.134793] [<ffffffff81037b0e>] intel_bts_interrupt+0x8e/0xd0 >> [36299.141543] [<ffffffff810338bf>] intel_pmu_handle_irq+0x4f/0x450 >> [36299.148482] [<ffffffff810bc288>] ? check_chain_key+0x128/0x1e0 >> [36299.155249] [<ffffffff8102a4ab>] perf_event_nmi_handler+0x2b/0x50 >> [36299.162273] [<ffffffff810185d0>] nmi_handle+0xa0/0x150 [snip] >> >> and >> >> [27716.785131] WARNING: CPU: 2 PID: 17655 at kernel/events/ring_buffer.c:282 >> perf_aux_output_begin+0x1ce/0x1f0() >> [27716.796157] Modules linked in: fuse x86_pkg_temp_thermal intel_powerclamp >> intel_rapl iosf_mbi coretemp kvm_intel kvm snd_hda_codec_realtek >> snd_hda_codec_hdmi snd_hda_codec_generic snd_hda_intel snd_hda_controller >> crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec aesni_intel >> snd_hda_core aes_x86_64 iTCO_wdt lrw snd_hwdep gf128mul snd_pcm >> iTCO_vendor_support ppdev i915snd_timer glue_helper evdev ablk_helper snd >> cryptd mei_me mei psmouse pcspkr soundcore serio_raw lpc_ich drm_kms_helper >> parport_pc battery tpm_tis mfd_core parport drm video tpm i2c_i801 >> i2c_algo_bit wmi processor button sg sr_mod cdrom sd_mod ehci_pci ehci_hcd >> ahci libahci libata xhci_pci xhci_hcd e1000e ptp scsi_mod crc32c_intel >> usbcore pps_core usb_common thermal fan thermal_sys >> [27716.873350] CPU: 2 PID: 17655 Comm: perf_fuzzer Tainted: G W >> 4.1.0-rc7+ #155 >> [27716.882671] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS FBKT72AUS >> 01/26/2014 >> [27716.891168] ffffffff81a230f2 ffff8800cf9afc68 ffffffff816d7229 >> 0000000000000000 >> [27716.899782] 0000000000000000 ffff8800cf9afca8 ffffffff81072eba >> 000000000000cf80 >> [27716.908372] ffff880036d85a00 ffff88011ea8cf80 ffff880119106000 >> 000000000000cf80 >> [27716.916981] Call Trace: >> [27716.920180] [<ffffffff816d7229>] dump_stack+0x45/0x57 >> [27716.926250] [<ffffffff81072eba>] warn_slowpath_common+0x8a/0xc0 >> [27716.933244] [<ffffffff81072faa>] warn_slowpath_null+0x1a/0x20 >> [27716.939999] [<ffffffff8116b00e>] perf_aux_output_begin+0x1ce/0x1f0 >> [27716.947225] [<ffffffff81164785>] ? perf_event_update_userpage+0x5/0x170 >> [27716.954875] [<ffffffff8103767d>] bts_event_add+0x6d/0x150 >> [27716.961259] [<ffffffff81162ddb>] event_sched_in.isra.85+0xfb/0x330 >> [27716.968495] [<ffffffff811630ca>] group_sched_in+0xba/0x1e0 >> [27716.974957] [<ffffffff8101df2a>] ? native_sched_clock+0x2a/0x90 >> [27716.981888] [<ffffffff811633c0>] ctx_sched_in+0x1d0/0x3f0 >> [27716.988274] [<ffffffff81163649>] perf_event_sched_in+0x69/0xa0 >> [27716.995082] [<ffffffff81163bc0>] perf_event_context_sched_in+0x90/0x160 >> [27717.002714] [<ffffffff81164148>] __perf_event_task_sched_in+0xa8/0xc0 >> [27717.010160] [<ffffffff8109897d>] finish_task_switch+0xed/0x140 >> [27717.016988] [<ffffffff81012723>] ? __switch_to+0x263/0x5d0 >> [27717.023400] [<ffffffff8109e5a1>] schedule_tail+0x11/0xa0 >> [27717.029652] [<ffffffff816df57f>] ret_from_fork+0xf/0x70 >> [27717.035806] ---[ end trace bdbfeef5d81e5fa4 ]--- >> >> which corresponds to >> /* >> * Nesting is not supported for AUX area, make sure nested >> * writers are caught early >> */ >> if (WARN_ON_ONCE(local_xchg(&rb->aux_nest, 1))) >> goto err_put; >> This really shouldn't happen, I'd need to check with the fuzzer. Thanks, -- Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
