On Thu, Nov 22, 2018 at 05:04:19PM +0800, zhe.he@xxxxxxxxxxxxx wrote: > From: He Zhe <zhe.he@xxxxxxxxxxxxx> > > kmemleak_lock, as a rwlock on RT, can possibly be held in atomic context and > causes the follow BUG. > > BUG: scheduling while atomic: migration/15/132/0x00000002 > Modules linked in: iTCO_wdt iTCO_vendor_support intel_rapl pcc_cpufreq > pnd2_edac intel_powerclamp coretemp crct10dif_pclmul crct10dif_common > aesni_intel matroxfb_base aes_x86_64 matroxfb_g450 matroxfb_accel > crypto_simd matroxfb_DAC1064 cryptd glue_helper g450_pll matroxfb_misc > i2c_ismt i2c_i801 acpi_cpufreq > Preemption disabled at: > [<ffffffff8c927c11>] cpu_stopper_thread+0x71/0x100 > CPU: 15 PID: 132 Comm: migration/15 Not tainted 4.19.0-rt1-preempt-rt #1 > Hardware name: Intel Corp. Harcuvar/Server, BIOS HAVLCRB1.X64.0015.D62.1708310404 08/31/2017 > Call Trace: > dump_stack+0x4f/0x6a > ? cpu_stopper_thread+0x71/0x100 > __schedule_bug.cold.16+0x38/0x55 > __schedule+0x484/0x6c0 > schedule+0x3d/0xe0 > rt_spin_lock_slowlock_locked+0x118/0x2a0 > rt_spin_lock_slowlock+0x57/0x90 > __rt_spin_lock+0x26/0x30 > __write_rt_lock+0x23/0x1a0 > ? intel_pmu_cpu_dying+0x67/0x70 > rt_write_lock+0x2a/0x30 > find_and_remove_object+0x1e/0x80 > delete_object_full+0x10/0x20 > kmemleak_free+0x32/0x50 > kfree+0x104/0x1f0 > ? x86_pmu_starting_cpu+0x30/0x30 > intel_pmu_cpu_dying+0x67/0x70 > x86_pmu_dying_cpu+0x1a/0x30 > cpuhp_invoke_callback+0x92/0x700 > take_cpu_down+0x70/0xa0 > multi_cpu_stop+0x62/0xc0 > ? cpu_stop_queue_work+0x130/0x130 > cpu_stopper_thread+0x79/0x100 > smpboot_thread_fn+0x20f/0x2d0 > kthread+0x121/0x140 > ? sort_range+0x30/0x30 > ? kthread_park+0x90/0x90 > ret_from_fork+0x35/0x40 > > And on v4.18 stable tree the following call trace, caused by grabbing > kmemleak_lock again, is also observed. > > kernel BUG at kernel/locking/rtmutex.c:1048! > invalid opcode: 0000 [#1] PREEMPT SMP PTI > CPU: 5 PID: 689 Comm: mkfs.ext4 Not tainted 4.18.16-rt9-preempt-rt #1 > Hardware name: Intel Corp. Harcuvar/Server, BIOS HAVLCRB1.X64.0015.D62.1708310404 08/31/2017 > RIP: 0010:rt_spin_lock_slowlock_locked+0x277/0x2a0 > Code: e8 5e 64 61 ff e9 bc fe ff ff e8 54 64 61 ff e9 b7 fe ff ff 0f 0b e8 98 57 53 ff e9 43 fe ff ff e8 8e 57 53 ff e9 74 ff ff ff <0f> 0b 0f 0b 0f 0b 48 8b 43 10 48 85 c0 74 06 48 3b 58 38 75 0b 49 > RSP: 0018:ffff936846d4f3b0 EFLAGS: 00010046 > RAX: ffff8e3680361e00 RBX: ffffffff83a8b240 RCX: 0000000000000001 > RDX: 0000000000000000 RSI: ffff8e3680361e00 RDI: ffffffff83a8b258 > RBP: ffff936846d4f3e8 R08: ffff8e3680361e01 R09: ffffffff82adfdf0 > R10: ffffffff827ede18 R11: 0000000000000000 R12: ffff936846d4f3f8 > R13: ffff8e3680361e00 R14: ffff936846d4f3f8 R15: 0000000000000246 > FS: 00007fc8b6bfd780(0000) GS:ffff8e369f340000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000055fb5659e000 CR3: 00000007fdd14000 CR4: 00000000003406e0 > Call Trace: > ? preempt_count_add+0x74/0xc0 > rt_spin_lock_slowlock+0x57/0x90 > ? __kernel_text_address+0x12/0x40 > ? __save_stack_trace+0x75/0x100 > __rt_spin_lock+0x26/0x30 > __write_rt_lock+0x23/0x1a0 > rt_write_lock+0x2a/0x30 > create_object+0x17d/0x2b0 > kmemleak_alloc+0x34/0x50 > kmem_cache_alloc+0x146/0x220 > ? mempool_alloc_slab+0x15/0x20 > mempool_alloc_slab+0x15/0x20 > mempool_alloc+0x65/0x170 > sg_pool_alloc+0x21/0x60 > __sg_alloc_table+0x101/0x160 > ? sg_free_table_chained+0x30/0x30 > sg_alloc_table_chained+0x8b/0xb0 > scsi_init_sgtable+0x31/0x90 > scsi_init_io+0x44/0x130 > sd_setup_write_same16_cmnd+0xef/0x150 > sd_init_command+0x6bf/0xaa0 > ? cgroup_base_stat_cputime_account_end.isra.0+0x26/0x60 > ? elv_rb_del+0x2a/0x40 > scsi_setup_cmnd+0x8e/0x140 > scsi_prep_fn+0x5d/0x140 > blk_peek_request+0xda/0x2f0 > scsi_request_fn+0x33/0x550 > ? cfq_rb_erase+0x23/0x40 > __blk_run_queue+0x43/0x60 > cfq_insert_request+0x2f3/0x5d0 > __elv_add_request+0x160/0x290 > blk_flush_plug_list+0x204/0x230 > schedule+0x87/0xe0 > __write_rt_lock+0x18b/0x1a0 > rt_write_lock+0x2a/0x30 > create_object+0x17d/0x2b0 > kmemleak_alloc+0x34/0x50 > __kmalloc_node+0x1cd/0x340 > alloc_request_size+0x30/0x70 > mempool_alloc+0x65/0x170 > ? ioc_lookup_icq+0x54/0x70 > get_request+0x4e3/0x8d0 > ? wait_woken+0x80/0x80 > blk_queue_bio+0x153/0x470 > generic_make_request+0x1dc/0x3f0 > submit_bio+0x49/0x140 > ? next_bio+0x38/0x40 > submit_bio_wait+0x59/0x90 > blkdev_issue_discard+0x7a/0xd0 > ? _raw_spin_unlock_irqrestore+0x18/0x50 > blk_ioctl_discard+0xc7/0x110 > blkdev_ioctl+0x57e/0x960 > ? __wake_up+0x13/0x20 > block_ioctl+0x3d/0x50 > do_vfs_ioctl+0xa8/0x610 > ? vfs_write+0x166/0x1b0 > ksys_ioctl+0x67/0x90 > __x64_sys_ioctl+0x1a/0x20 > do_syscall_64+0x4d/0xf0 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > kmemleak is an error detecting feature. We would not expect as good performance > as without it. As there is no raw rwlock defining helpers, we turn kmemleak_lock > to a raw spinlock. > > Signed-off-by: He Zhe <zhe.he@xxxxxxxxxxxxx> > Cc: catalin.marinas@xxxxxxx > Cc: bigeasy@xxxxxxxxxxxxx > Cc: tglx@xxxxxxxxxxxxx > Cc: rostedt@xxxxxxxxxxx As I replied already, I don't think this patch would increase the kmemleak latency (or performance), although I haven't actually tested it. FWIW: Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
