Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752462AbbGNMrP (ORCPT ); Tue, 14 Jul 2015 08:47:15 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:34112 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751568AbbGNMrO (ORCPT ); Tue, 14 Jul 2015 08:47:14 -0400 Subject: Re: [RFC 2/3] arm64: refactor save_stack_trace() Mime-Version: 1.0 (Apple Message framework v1283) Content-Type: text/plain; charset=us-ascii From: Jungseok Lee In-Reply-To: <1436765375-7119-3-git-send-email-takahiro.akashi@linaro.org> Date: Tue, 14 Jul 2015 21:47:10 +0900 Cc: catalin.marinas@arm.com, will.deacon@arm.com, rostedt@goodmis.org, olof@lixom.net, broonie@kernel.org, david.griego@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 7bit Message-Id: References: <1436765375-7119-1-git-send-email-takahiro.akashi@linaro.org> <1436765375-7119-3-git-send-email-takahiro.akashi@linaro.org> To: AKASHI Takahiro X-Mailer: Apple Mail (2.1283) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3958 Lines: 90 On Jul 13, 2015, at 2:29 PM, AKASHI Takahiro wrote: Hi, AKASHI > Ftrace's stack tracer on arm64 returns wrong information about call stacks: > > Depth Size Location (50 entries) > ----- ---- -------- > 0) 5256 0 notifier_call_chain+0x30/0x94 > 1) 5256 0 ftrace_call+0x0/0x4 > 2) 5256 0 notifier_call_chain+0x2c/0x94 > 3) 5256 0 raw_notifier_call_chain+0x34/0x44 > 4) 5256 0 timekeeping_update.constprop.9+0xb8/0x114 > 5) 5256 0 update_wall_time+0x408/0x6dc > > One of tracer functions, ftrace_call (or mcount), is unexpectedly listed. > The *bare* stack dump returned by save_stack_trace() is: > save_stack_trace_tsk() > save_stack_trace() > stack_trace_call() > ftrace_ops_no_ops() > ftrace_call() > notifier_call_chain() > raw_notifier_call_chain() > ... Is the below example an unexpected result? Entry 17 and 18 are ftrace_call and ftrace_ops_no_ops, respectively. Depth Size Location (51 entries) ----- ---- -------- 0) 5352 96 _raw_spin_unlock_irqrestore+0x1c/0x60 1) 5256 48 gic_raise_softirq+0xa0/0xbc 2) 5208 80 smp_cross_call+0x40/0xbc 3) 5128 48 smp_send_reschedule+0x38/0x48 4) 5080 32 trigger_load_balance+0x184/0x29c 5) 5048 112 scheduler_tick+0xac/0x104 6) 4936 64 update_process_times+0x5c/0x74 7) 4872 32 tick_sched_handle.isra.15+0x38/0x7c 8) 4840 48 tick_sched_timer+0x48/0x90 9) 4792 48 __run_hrtimer+0x60/0x258 10) 4744 64 hrtimer_interrupt+0xe8/0x260 11) 4680 128 arch_timer_handler_virt+0x38/0x48 12) 4552 32 handle_percpu_devid_irq+0x84/0x188 13) 4520 64 generic_handle_irq+0x38/0x54 14) 4456 32 __handle_domain_irq+0x68/0xbc 15) 4424 64 gic_handle_irq+0x38/0x88 16) 4360 280 el1_irq+0x64/0xd8 17) 4080 168 ftrace_ops_no_ops+0xb4/0x16c 18) 3912 32 ftrace_call+0x0/0x4 19) 3880 144 __alloc_skb+0x48/0x180 20) 3736 96 alloc_skb_with_frags+0x74/0x234 21) 3640 112 sock_alloc_send_pskb+0x1d0/0x294 22) 3528 160 sock_alloc_send_skb+0x44/0x54 23) 3368 64 __ip_append_data.isra.40+0x78c/0xb48 24) 3304 224 ip_append_data.part.42+0x98/0xe8 25) 3080 112 ip_append_data+0x68/0x7c 26) 2968 96 icmp_push_reply+0x7c/0x144 27) 2872 96 icmp_send+0x3c0/0x3c8 28) 2776 192 __udp4_lib_rcv+0x5b8/0x684 29) 2584 96 udp_rcv+0x2c/0x3c 30) 2488 32 ip_local_deliver+0xa0/0x224 31) 2456 48 ip_rcv+0x360/0x57c 32) 2408 64 __netif_receive_skb_core+0x4d0/0x80c 33) 2344 128 __netif_receive_skb+0x24/0x84 34) 2216 32 process_backlog+0x9c/0x15c 35) 2184 80 net_rx_action+0x1ec/0x32c 36) 2104 160 __do_softirq+0x114/0x2f0 37) 1944 128 do_softirq+0x60/0x68 38) 1816 32 __local_bh_enable_ip+0xb0/0xd4 39) 1784 32 ip_finish_output+0x1f4/0xabc 40) 1752 96 ip_output+0xf0/0x120 41) 1656 64 ip_local_out_sk+0x44/0x54 42) 1592 32 ip_send_skb+0x24/0xbc 43) 1560 48 udp_send_skb+0x1b4/0x2f4 44) 1512 80 udp_sendmsg+0x2a8/0x7a0 45) 1432 272 inet_sendmsg+0xa0/0xd0 46) 1160 48 sock_sendmsg+0x30/0x78 47) 1112 32 ___sys_sendmsg+0x15c/0x26c 48) 1080 400 __sys_sendmmsg+0x94/0x180 49) 680 320 SyS_sendmmsg+0x38/0x54 50) 360 360 el0_svc_naked+0x20/0x28 Best Regards Jungseok Lee -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/