Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755821AbbGPPbV (ORCPT ); Thu, 16 Jul 2015 11:31:21 -0400 Received: from smtprelay0082.hostedemail.com ([216.40.44.82]:48076 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755793AbbGPPbU (ORCPT ); Thu, 16 Jul 2015 11:31:20 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::::,RULES_HIT:2:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1535:1593:1594:1605:1606:1730:1747:1777:1792:1981:2194:2196:2199:2200:2393:2553:2559:2562:2895:3138:3139:3140:3141:3142:3622:3865:3866:3867:3868:3870:3871:3872:3873:4118:4321:4605:5007:6119:6120:6248:6261:7514:7875:7903:8531:8603:10004:10848:10967:11026:11232:11658:11914:12043:12296:12438:12517:12519:12740:21060:21063:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: bears94_62aa2063daa3d X-Filterd-Recvd-Size: 7277 Date: Thu, 16 Jul 2015 11:31:15 -0400 From: Steven Rostedt To: Jungseok Lee Cc: AKASHI Takahiro , catalin.marinas@arm.com, will.deacon@arm.com, olof@lixom.net, broonie@kernel.org, david.griego@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RFC 2/3] arm64: refactor save_stack_trace() Message-ID: <20150716113115.45a17f17@gandalf.local.home> In-Reply-To: <12F47692-3010-4886-B87D-3D7820609177@gmail.com> References: <1436765375-7119-1-git-send-email-takahiro.akashi@linaro.org> <1436765375-7119-3-git-send-email-takahiro.akashi@linaro.org> <20150714093154.4d73e551@gandalf.local.home> <55A5A75A.1060401@linaro.org> <20150714225105.6c1e4f15@gandalf.local.home> <55A646EE.6030402@linaro.org> <20150715105536.42949ea9@gandalf.local.home> <20150715121337.3b31aa84@gandalf.local.home> <55A6FA82.9000901@linaro.org> <55A703F3.8050203@linaro.org> <20150716102405.2cc8c406@gandalf.local.home> <12F47692-3010-4886-B87D-3D7820609177@gmail.com> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.28; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5805 Lines: 143 On Fri, 17 Jul 2015 00:01:25 +0900 Jungseok Lee wrote: > I've gathered stack tracer data with your update. > > 1) stack_trace > Depth Size Location (35 entries) > ----- ---- -------- > 0) 4424 16 put_cpu_partial+0x28/0x1d0 > 1) 4408 80 get_partial_node.isra.64+0x13c/0x344 > 2) 4328 256 __slab_alloc.isra.65.constprop.67+0xd8/0x37c > 3) 4072 32 kmem_cache_alloc+0x258/0x294 > 4) 4040 304 __alloc_skb+0x48/0x180 > 5) 3736 96 alloc_skb_with_frags+0x74/0x234 > 6) 3640 112 sock_alloc_send_pskb+0x1d0/0x294 > 7) 3528 160 sock_alloc_send_skb+0x44/0x54 > 8) 3368 64 __ip_append_data.isra.40+0x78c/0xb48 > 9) 3304 224 ip_append_data.part.42+0x98/0xe8 > 10) 3080 112 ip_append_data+0x68/0x7c > 11) 2968 96 icmp_push_reply+0x7c/0x144 > 12) 2872 96 icmp_send+0x3c0/0x3c8 > 13) 2776 192 __udp4_lib_rcv+0x5b8/0x684 > 14) 2584 96 udp_rcv+0x2c/0x3c > 15) 2488 32 ip_local_deliver+0xa0/0x224 > 16) 2456 48 ip_rcv+0x360/0x57c > 17) 2408 64 __netif_receive_skb_core+0x4d0/0x80c > 18) 2344 128 __netif_receive_skb+0x24/0x84 > 19) 2216 32 process_backlog+0x9c/0x15c > 20) 2184 80 net_rx_action+0x1ec/0x32c > 21) 2104 160 __do_softirq+0x114/0x2f0 > 22) 1944 128 do_softirq+0x60/0x68 > 23) 1816 32 __local_bh_enable_ip+0xb0/0xd4 > 24) 1784 32 ip_finish_output+0x1f4/0xabc > 25) 1752 96 ip_output+0xf0/0x120 > 26) 1656 64 ip_local_out_sk+0x44/0x54 > 27) 1592 32 ip_send_skb+0x24/0xbc > 28) 1560 48 udp_send_skb+0x1b4/0x2f4 > 29) 1512 80 udp_sendmsg+0x2a8/0x7a0 > 30) 1432 272 inet_sendmsg+0xa0/0xd0 > 31) 1160 48 sock_sendmsg+0x30/0x78 > 32) 1112 32 ___sys_sendmsg+0x15c/0x26c > 33) 1080 400 __sys_sendmmsg+0x94/0x180 > 34) 680 320 SyS_sendmmsg+0x38/0x54 > 35) 360 360 el0_svc_naked+0x20/0x28 > > 2) stack_max_size > 4504 Strange, on x86 I have this (with my patch applied): Depth Size Location (39 entries) ----- ---- -------- 0) 3704 64 _raw_spin_lock+0x5/0x30 1) 3640 200 get_partial_node.isra.80+0x54/0x1da 2) 3440 208 __slab_alloc.isra.82+0x199/0x3f7 3) 3232 80 kmem_cache_alloc+0x151/0x160 4) 3152 16 mempool_alloc_slab+0x15/0x20 5) 3136 128 mempool_alloc+0x58/0x150 6) 3008 16 scsi_sg_alloc+0x42/0x50 7) 2992 112 __sg_alloc_table+0x10b/0x150 8) 2880 48 scsi_alloc_sgtable+0x43/0x80 9) 2832 32 scsi_init_sgtable+0x2b/0x70 10) 2800 80 scsi_init_io+0x59/0x1e0 11) 2720 128 sd_init_command+0x66/0xd80 12) 2592 24 scsi_setup_cmnd+0xa9/0x160 13) 2568 88 scsi_prep_fn+0x7d/0x160 14) 2480 48 blk_peek_request+0x168/0x2a0 15) 2432 112 scsi_request_fn+0x3f/0x610 16) 2320 8 __blk_run_queue+0x37/0x50 17) 2312 104 queue_unplugged+0x41/0xe0 18) 2208 112 blk_flush_plug_list+0x1b7/0x1e0 19) 2096 80 blk_queue_bio+0x257/0x340 20) 2016 48 generic_make_request+0xb1/0xf0 21) 1968 96 submit_bio+0x76/0x130 22) 1872 48 submit_bh_wbc.isra.35+0x10b/0x140 23) 1824 112 __block_write_full_page.constprop.40+0x188/0x310 24) 1712 64 block_write_full_page+0xdd/0x130 25) 1648 16 blkdev_writepage+0x18/0x20 26) 1632 8 __writepage+0x17/0x40 27) 1624 312 write_cache_pages+0x21e/0x480 28) 1312 96 generic_writepages+0x4a/0x70 29) 1216 16 do_writepages+0x20/0x30 30) 1200 96 __writeback_single_inode+0x45/0x350 31) 1104 176 writeback_sb_inodes+0x218/0x3d0 32) 928 80 __writeback_inodes_wb+0x8c/0xc0 33) 848 128 wb_writeback+0x239/0x2c0 34) 720 192 wb_workfn+0x24b/0x460 35) 528 80 process_one_work+0x14b/0x430 36) 448 128 worker_thread+0x117/0x460 37) 320 144 kthread+0xc9/0xe0 38) 176 176 ret_from_fork+0x3f/0x70 # cat /debug/tracing/stack_max_size 3704 > > In case of the number of entries, the following diff might be needed > as I suggested in the previous reply. ;) > > ----8<---- > > @@ -330,7 +333,7 @@ static int t_show(struct seq_file *m, void *v) > seq_printf(m, " Depth Size Location" > " (%d entries)\n" > " ----- ---- --------\n", > - max_stack_trace.nr_entries - 1); > + max_stack_trace.nr_entries); This would break x86. > > if (!stack_tracer_enabled && !max_stack_size) > print_disabled(m); > > ----8<---- > > However, 80-byte gap still appears. This seems to be specific to your arch. > > Since max_stack_trace.skip is 3 in your update, save_stack_trace in arm64 > should be refactored to align with this value. > > max_stack_trace.skip should be set to 4 if AKASHI's [RFC 2/3] patch is merged. > However, arch code is supposed to follow generic framework's rule in this case. > Isn't it? > yeah, you don't want to update the skip level. It should just work. I'll run this on my powerpc box and see if it shows something different. If I have to, I'll even boot up my arm (not 64) board and try it there. -- Steve -- 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/