From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it1-f197.google.com (mail-it1-f197.google.com [209.85.166.197]) by kanga.kvack.org (Postfix) with ESMTP id 980238E0002 for ; Sat, 19 Jan 2019 06:32:05 -0500 (EST) Received: by mail-it1-f197.google.com with SMTP id m128so5965028itd.3 for ; Sat, 19 Jan 2019 03:32:05 -0800 (PST) Received: from mail-sor-f69.google.com (mail-sor-f69.google.com. [209.85.220.69]) by mx.google.com with SMTPS id b21sor3428882ios.82.2019.01.19.03.32.04 for (Google Transport Security); Sat, 19 Jan 2019 03:32:04 -0800 (PST) MIME-Version: 1.0 Date: Sat, 19 Jan 2019 03:32:03 -0800 Message-ID: <00000000000010b2fc057fcdfaba@google.com> Subject: INFO: rcu detected stall in sys_sendfile64 (2) From: syzbot Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, amir73il@gmail.com, darrick.wong@oracle.com, david@fromorbit.com, hannes@cmpxchg.org, hughd@google.com, jrdr.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, willy@infradead.org Hello, syzbot found the following crash on: HEAD commit: 2339e91d0e66 Merge tag 'media/v5.0-1' of git://git.kernel... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=175f2638c00000 kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258 dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com audit: type=1400 audit(1547895693.874:36): avc: denied { map } for pid=8427 comm="syz-executor786" path="/root/syz-executor786610373" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 hrtimer: interrupt took 42996 ns rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=6469, q=3) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295051508-4295041006), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor786 R running task 21544 8437 8433 0x00000000 Call Trace: sched_show_task kernel/sched/core.c:5293 [inline] sched_show_task.cold+0x273/0x2d5 kernel/sched/core.c:5268 print_other_cpu_stall.cold+0x7f2/0x8bb kernel/rcu/tree.c:1301 check_cpu_stall kernel/rcu/tree.c:1429 [inline] rcu_pending kernel/rcu/tree.c:3018 [inline] rcu_check_callbacks+0xf36/0x1380 kernel/rcu/tree.c:2521 update_process_times+0x32/0x80 kernel/time/timer.c:1635 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline] RIP: 0010:write_comp_data+0x9/0x70 kernel/kcov.c:122 Code: 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 <65> 8b 05 80 ee 7f 7e a9 00 01 1f 00 75 51 41 8b 80 d8 12 00 00 83 RSP: 0018:ffff888080466f58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 000000000000226d RBX: ffff888080467140 RCX: ffffffff87f08bdf RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000007 RBP: ffff888080466f60 R08: ffff888096338480 R09: ffffed1015cc5b90 R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: 1ffff1101008cdf0 R13: ffff888092b64102 R14: ffff888092b64102 R15: ffff888080467158 xa_is_node include/linux/xarray.h:946 [inline] xas_start+0x1cf/0x720 lib/xarray.c:183 xas_load+0x21/0x160 lib/xarray.c:227 find_get_entry+0x350/0x10a0 mm/filemap.c:1476 pagecache_get_page+0xe6/0x1020 mm/filemap.c:1579 find_get_page include/linux/pagemap.h:272 [inline] generic_file_buffered_read mm/filemap.c:2076 [inline] generic_file_read_iter+0x7b2/0x2d40 mm/filemap.c:2350 ext4_file_read_iter+0x180/0x3c0 fs/ext4/file.c:77 call_read_iter include/linux/fs.h:1856 [inline] generic_file_splice_read+0x5c4/0xa90 fs/splice.c:308 do_splice_to+0x12a/0x190 fs/splice.c:880 splice_direct_to_actor+0x31b/0x9d0 fs/splice.c:957 do_splice_direct+0x2c7/0x420 fs/splice.c:1066 do_sendfile+0x61a/0xe60 fs/read_write.c:1436 __do_sys_sendfile64 fs/read_write.c:1491 [inline] __se_sys_sendfile64 fs/read_write.c:1483 [inline] __x64_sys_sendfile64+0x15a/0x240 fs/read_write.c:1483 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x446a19 Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f53e33cfda8 EFLAGS: 00000297 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000446a19 RDX: 0000000020000380 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000297 R12: 00000000006dcc2c R13: 00008080fffffffe R14: 00007f53e33d09c0 R15: 00000000006dcd2c rcu: rcu_preempt kthread starved for 10502 jiffies! g6469 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 26200 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1803 rcu_gp_fqs_loop+0x6ba/0x970 kernel/rcu/tree.c:1948 rcu_gp_kthread+0x2bb/0xc10 kernel/rcu/tree.c:2105 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 sched: RT throttling activated --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.7 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1B7AC61CE4 for ; Sat, 19 Jan 2019 11:32:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 725CA20821 for ; Sat, 19 Jan 2019 11:32:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 725CA20821 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DE23B8E0003; Sat, 19 Jan 2019 06:32:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D6A108E0002; Sat, 19 Jan 2019 06:32:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C5BC98E0003; Sat, 19 Jan 2019 06:32:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-it1-f197.google.com (mail-it1-f197.google.com [209.85.166.197]) by kanga.kvack.org (Postfix) with ESMTP id 980238E0002 for ; Sat, 19 Jan 2019 06:32:05 -0500 (EST) Received: by mail-it1-f197.google.com with SMTP id m128so5965028itd.3 for ; Sat, 19 Jan 2019 03:32:05 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:mime-version :date:message-id:subject:from:to; bh=IWHW3E/586yQ4o2zLnYO0TwsG10I99V4RUW+P2JvPdI=; b=EiGkQ9HeUDskhYS2PTH03B+OjOZgg3XDjIgVKmiREDZVVeVNeSsPrr/ce2B7TBQMOo yZGnNUta4Q0tW8B+6U1j+w6d03m0mx846/O7L2h9QWhvlJhUFTHdKOJtREezi2gc7WQC 5zzglsvw5ez20taezq7OAH8Cy1zFJvlqQ4njmLFGk7/OBJDBkbCod7kItag8IcLH5DVv bCNDVJjnyxuiC6AIEIJKsOCV2Glc3grs9kU21tVAhIh5MYiuMDdGC+mEmX2sFz3xpYl2 YroqcOXIfS+Ofgk+gdh5o4gLaJd2B2LDbchfOryIMXL01arNmBLXLXZMox7DhSCU2YQU MuPw== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of 3swpdxakbalwu01mcnngtcrrkf.iqqingwugteqpvgpv.eqo@m3kw2wvrgufz5godrsrytgd7.apphosting.bounces.google.com designates 209.85.220.69 as permitted sender) smtp.mailfrom=3swpDXAkbALwu01mcnngtcrrkf.iqqingwugteqpvgpv.eqo@M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=appspotmail.com X-Gm-Message-State: AJcUukfXqIYqtghIK1PHJfwDWRW2R04xVO+av0ALX3kgdPPr780OVBDo IZiSNVaLf27d8MnUmObDEApjtbrL3/hHPV0q6AUgihcGwJlZNmqqrPNew4r6kcVtMLO8rTyuiDT CY77qhccc/bjmUmGMXcZ6YgutKyoKOE0+K7LijzoNzi3w+hX7cE1vRWsQRvgtylwAACM2Div2fE 5bDw9GwxijqMpWbF1tNfGbhvBEM9ICNVJtdCQuWJWyN14YHpD4OZnb+ojpsJBGiL1YWtpbafij8 tSBWlQqb0o34MQmxC4L1MuSVDby7CwBhLTdPMz5OaDvKFGIGTR9XuNf+VHQUwYUZN/4z5TV5Eiy 60I9GOAccNQZPWhkyi+iKq8E5Jj5SuLnMBMGDDsT7Emx/P/sibtZOcfwWb6SrjS/OljsaPNjhw= = X-Received: by 2002:a24:f30b:: with SMTP id t11mr11338126ith.40.1547897525368; Sat, 19 Jan 2019 03:32:05 -0800 (PST) X-Received: by 2002:a24:f30b:: with SMTP id t11mr11338101ith.40.1547897524267; Sat, 19 Jan 2019 03:32:04 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1547897524; cv=none; d=google.com; s=arc-20160816; b=mWO8XCes3nTM97GZH+nYRs7VFYVR+wGsOPDUAlnTS8kuLtwnyJPgwG8DoFa9xsKtof obDXGS9sWbLAkj0CZlL434DIqqZbfWFReT858gcClOsAZVwgWftKNPCsFa+rYl0Z5wTY TtrvlJwp+bod2IRAH6smef5IIpzuCKcKeZiHW0Z+fjEdu3gkUnKG59f2OMfRlfp3xPQi tuZyBRmOTTlSUTuInRFDoQDI3wY+EG78ehTk7S2/1zfeF0ERGt1EFyZL7rj9OJPdovjI PAdzqji7UDz21D1a0i5UA0ZpgFb2KngVMNoJMlDpmgOfDzZUjJstBMxzQ6L+FHFmVFpq X4Sw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=to:from:subject:message-id:date:mime-version; bh=IWHW3E/586yQ4o2zLnYO0TwsG10I99V4RUW+P2JvPdI=; b=KpE/NhZmEkdSg2tnGER1chUcqcp/W0b8HMBOyh0CTyfPEcWpTkW8kV+iUgzQ+r7iMG BiLHnNiMhyoaTHpRgQfmr7iZ8sazsCnlIeeqrELkEks8tTzY5ryL5apwKHhJ29cW1Fb+ qsTwcoKA94JyvZq7FhvYZWbtemlARPDF5ySnkD1HdunbcLFbcajcu3f2E5COx4Z/hYgr vVGd3yrzeGiit8FljgraCPUqi+cInAuqZ71GsMR6dDF+SH6FmgW4HMkQ9w6Eq3iC/DM+ WQqwLHCSaou2b1zNdh1lYEvaIWblhVXO5onIjH/X7nlsFdhHlphVqBs1JDvmmLBJl+p3 /uLw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of 3swpdxakbalwu01mcnngtcrrkf.iqqingwugteqpvgpv.eqo@m3kw2wvrgufz5godrsrytgd7.apphosting.bounces.google.com designates 209.85.220.69 as permitted sender) smtp.mailfrom=3swpDXAkbALwu01mcnngtcrrkf.iqqingwugteqpvgpv.eqo@M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=appspotmail.com Received: from mail-sor-f69.google.com (mail-sor-f69.google.com. 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Sat, 19 Jan 2019 03:32:03 -0800 (PST) Date: Sat, 19 Jan 2019 03:32:03 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000010b2fc057fcdfaba@google.com> Subject: INFO: rcu detected stall in sys_sendfile64 (2) From: syzbot To: akpm@linux-foundation.org, amir73il@gmail.com, darrick.wong@oracle.com, david@fromorbit.com, hannes@cmpxchg.org, hughd@google.com, jrdr.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, willy@infradead.org Content-Type: text/plain; charset="UTF-8"; delsp="yes"; format="flowed" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Message-ID: <20190119113203.W7zpwFzV6udP6mIjShkQ7-1t4dVuHwsV5pC3pgqe66E@z> Hello, syzbot found the following crash on: HEAD commit: 2339e91d0e66 Merge tag 'media/v5.0-1' of git://git.kernel... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=175f2638c00000 kernel config: https://syzkaller.appspot.com/x/.config?x=abc3dc9b7a900258 dashboard link: https://syzkaller.appspot.com/bug?extid=1505c80c74256c6118a5 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c4dc28c00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15df4108c00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+1505c80c74256c6118a5@syzkaller.appspotmail.com audit: type=1400 audit(1547895693.874:36): avc: denied { map } for pid=8427 comm="syz-executor786" path="/root/syz-executor786610373" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 hrtimer: interrupt took 42996 ns rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=6469, q=3) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295051508-4295041006), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor786 R running task 21544 8437 8433 0x00000000 Call Trace: sched_show_task kernel/sched/core.c:5293 [inline] sched_show_task.cold+0x273/0x2d5 kernel/sched/core.c:5268 print_other_cpu_stall.cold+0x7f2/0x8bb kernel/rcu/tree.c:1301 check_cpu_stall kernel/rcu/tree.c:1429 [inline] rcu_pending kernel/rcu/tree.c:3018 [inline] rcu_check_callbacks+0xf36/0x1380 kernel/rcu/tree.c:2521 update_process_times+0x32/0x80 kernel/time/timer.c:1635 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline] RIP: 0010:write_comp_data+0x9/0x70 kernel/kcov.c:122 Code: 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 <65> 8b 05 80 ee 7f 7e a9 00 01 1f 00 75 51 41 8b 80 d8 12 00 00 83 RSP: 0018:ffff888080466f58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 000000000000226d RBX: ffff888080467140 RCX: ffffffff87f08bdf RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000007 RBP: ffff888080466f60 R08: ffff888096338480 R09: ffffed1015cc5b90 R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: 1ffff1101008cdf0 R13: ffff888092b64102 R14: ffff888092b64102 R15: ffff888080467158 xa_is_node include/linux/xarray.h:946 [inline] xas_start+0x1cf/0x720 lib/xarray.c:183 xas_load+0x21/0x160 lib/xarray.c:227 find_get_entry+0x350/0x10a0 mm/filemap.c:1476 pagecache_get_page+0xe6/0x1020 mm/filemap.c:1579 find_get_page include/linux/pagemap.h:272 [inline] generic_file_buffered_read mm/filemap.c:2076 [inline] generic_file_read_iter+0x7b2/0x2d40 mm/filemap.c:2350 ext4_file_read_iter+0x180/0x3c0 fs/ext4/file.c:77 call_read_iter include/linux/fs.h:1856 [inline] generic_file_splice_read+0x5c4/0xa90 fs/splice.c:308 do_splice_to+0x12a/0x190 fs/splice.c:880 splice_direct_to_actor+0x31b/0x9d0 fs/splice.c:957 do_splice_direct+0x2c7/0x420 fs/splice.c:1066 do_sendfile+0x61a/0xe60 fs/read_write.c:1436 __do_sys_sendfile64 fs/read_write.c:1491 [inline] __se_sys_sendfile64 fs/read_write.c:1483 [inline] __x64_sys_sendfile64+0x15a/0x240 fs/read_write.c:1483 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x446a19 Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f53e33cfda8 EFLAGS: 00000297 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000446a19 RDX: 0000000020000380 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000297 R12: 00000000006dcc2c R13: 00008080fffffffe R14: 00007f53e33d09c0 R15: 00000000006dcd2c rcu: rcu_preempt kthread starved for 10502 jiffies! g6469 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 26200 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1803 rcu_gp_fqs_loop+0x6ba/0x970 kernel/rcu/tree.c:1948 rcu_gp_kthread+0x2bb/0xc10 kernel/rcu/tree.c:2105 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 sched: RT throttling activated --- This bug is generated by a bot. 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